Free file tools and random pickers

Spin a wheel, pick a number, roll dice or make teams. File tools run on your device, so nothing you add is uploaded.

Free
No signup
Works on phones
Files and lists stay on your device

Not sure which tool?

Pick one name in front of a group: Wheel of Names
Get a random number in a range: Random Number Generator
Split people into teams: Team Maker
Make a photo fit an upload size limit: Compress Image
Join several PDFs into one: Merge PDF
Put a list in random order: Shuffle List
Settle a two-way choice: Coin Flipper
Roll dice without dice: Dice Roller
Turn photos or scans into a PDF: Images to PDF
Make a QR code: QR Code Generator

Random pickers

All random pickers

Spin a wheel, flip a coin, roll dice, draw cards or split a list into teams.

Wheel of Names: Spin a wheel to pick a name for draws and raffles.
Random Number: Generate numbers within any range.
Coin Flipper: Flip a coin for a quick heads or tails call.
Dice Roller: Roll d4 to d20 dice, one or many, with a total.
Team Maker: Split names into random teams or groups of a set size.
Lottery Generator: Random quick-pick tickets for lottery games.
Shuffle List: Randomize a list, pick the first few and copy.
Magic 8-Ball: Ask a yes or no question and get an answer.
Card Dealer: Shuffle and deal from a 52-card deck.
Stock Picker: Discover random market tickers.
ARCL Points: Cricket net run rate calculator and points simulator.
Business Name Generator: Make up to 60 business name ideas from your keywords and industry. Choose compound, blend, prefix or suffix, rhyme or invented names.
D&D Dice Roller: Roll dice notation such as 2d6+3, 4d6kh3 or d20 advantage, and see the exact chance of every total and of beating a target number.
Random Color: Pick 1 to 20 random colors, any, pastel, dark or vivid, with HEX, RGB and HSL codes. Runs in your browser.
Random Country: Pick 1 to 20 of the 195 UN member and observer states, by continent, with flags. Runs in your browser.
Random Date: Pick 1 to 100 dates between a start and an end date. Weekdays only, no repeats, four formats. Runs in your browser.
Random Letter: Pick one letter or up to 100, from A to Z, vowels or consonants. Runs in your browser.
Random Name Generator: Make 1 to 100 random names from eight regions. This makes names up; to pick from your own list, use Random Name Picker.
Random Name Picker: Paste your names, pick 1 to 100 winners, add weights if you want. Names stay in your browser.
Random Pairs: Paste names, get random pairs or trios, and keep chosen people apart. Runs in your browser.
Random Word: Pick 1 to 50 common English words. Choose nouns, verbs or adjectives, and short, medium or long. Runs in your browser.
Seating Chart: Paste names, set seats per row and get a random seating chart. Keep chosen people in the front row.
Secret Santa: Paste names, add couples who must not draw each other, and get the matches. The organiser sees all of them.
Truth or Dare: Get a random truth or dare for kids, teens or adults. 120 clean prompts, no repeats, and a turn order for your players.
Username Generator: Make 1 to 50 usernames from family-friendly word lists, with your own word if you like.
Would You Rather: Get a random would you rather question from 298 ones. Pick funny, deep, kids, food, travel or work, with a family-friendly switch.
Yes or No: Type a question, press the button and get Yes or No. Add Maybe if you want. Runs in your browser.

Photos & images

All image tools

Compress, resize, crop, convert, blur, rotate or read text from a picture.

Compress Image: Hit 20 KB, 100 KB or any limit.
Resize Image: Set exact pixels, a percentage or a social media size.
Image Converter: Convert between JPG, PNG and WebP.
Crop Image: Crop to any ratio or a circle.
Image to Text: Read text from images.
Rotate Image: Turn, flip or straighten photos.
Add Border to Image: Frame photos with a coloured border, optional padding and a square, 4:5 or 16:9 shape.
Add Text to Image: Put text on a photo. Up to 10 texts, outline, shadow, drag to place. Original size,.
Black and White Image: Greyscale, black and white or sepia, with a live preview.
Blur Image: Hide faces, text and numbers in a picture.
Brightness and Contrast: Four sliders with a live preview and stated formulas.
Change Image DPI: Set 72, 96, 150, 300, 600 or your own DPI in a JPEG or PNG. Pixels untouched,.
Color Blindness Simulator: See a picture as protanopia, deuteranopia, tritanopia or achromatopsia shows it. Compare and save PNGs,.
Combine Images: Join images into one, stacked or side by side.
EXIF Viewer: Camera, lens, exposure, date and location, listed per photo.
GIF Maker: Put 2 to 50 pictures in order, set the delay and repeat, download one GIF.
Image Color Picker: Click a pixel to read its HEX, RGB and HSL. Magnifier and keyboard included.
Image Diff: Mark the pixels that changed, see the percentage and the area, and download the result as a PNG.
Image to ASCII: Convert a picture to text characters. Pick the width and characters, copy or download.
Image to Base64: Get the Base64 text, a data URI, an img tag or a CSS rule for a picture.
Invert Image Colors: Make a negative, or flip only light and dark. Live preview,.
Make Background Transparent: Remove a plain white or solid background by colour. Click to pick, preview on a checkerboard,.
Photo to Coloring Page: Turn a photo or cartoon into a clean coloring page: closed black outlines on white, with Style, Detail and Line weight controls, saved as PNG or printable PDF.
Placeholder Image Generator: Pick a size and two colours, get a PNG, JPEG, WebP or SVG with the size written on it. Made in your browser.
PNG to SVG: Trace a logo or flat artwork into SVG shapes. Pick a preset, preview it, download.
QR Code Scanner: Add a photo or screenshot, or use your camera. See what the code holds before anything is opened.
Remove Background: An AI model finds the subject and cuts it out. Transparent, solid colour or your own picture. It runs.
Remove Photo Metadata: See what your photos reveal, then remove it.
Round Image Corners: Set a corner radius, pick which corners, save a PNG with clear corners.
Sharpen Image: Sharpen soft or slightly blurry photos with amount, radius and threshold, and check the result at 100 percent before you save.
Split Image: Cut one picture into rows and columns for a carousel or a profile grid. Numbered tiles, one zip.
Watermark Images: Add a text or logo watermark to many photos at once.

PDFs

All PDF tools

Merge, split, compress, reorder, number or convert PDFs.

Merge PDF: Combine PDFs in any order.
Split PDF: Split a PDF or pull out the pages you need.
Compress PDF: Shrink scanned PDFs. Text becomes an image.
Images to PDF: Turn photos and scans into one PDF.
PDF to JPG: Turn PDF pages into JPG or PNG images.
Organize PDF: Reorder, rotate and delete PDF pages.
Add text to PDF: Type text onto any page, or fill a flat PDF form.
Compare PDF: Line up the pages of two PDFs, list the text that changed, and mark the pixels that differ in red.
Crop PDF: Trim the margins off every page of a PDF.
Extract PDF images: Save the pictures embedded in a PDF, as they are stored.
Fill PDF form: Type into the fields of a PDF form, then save it.
Markdown to PDF: Turn Markdown with headings, lists, tables and code into a paginated A4 or Letter PDF, and check each page first.
Number PDF pages: Add page numbers to any PDF.
PDF Booklet Maker: Put two pages on each landscape sheet in the order a folded, stapled booklet needs, padded with blanks to a multiple of 4.
PDF metadata: See and change a PDF's title, author, subject and keywords.
PDF to Excel: Find the tables in a text PDF from the position of the words, preview them, and save an .xlsx or a CSV.
PDF to Markdown: Turn the text of a PDF into Markdown with headings and lists.
PDF to Text: Pull the text out of a PDF.
PDF to Word: Turn the text of a PDF into an editable Word file with headings and lists.
Protect PDF: Lock a PDF with an open password and AES encryption.
Redact PDF: Draw black boxes or search for words to cover. Each redacted page becomes a picture, so nothing is left to copy.
Resize PDF pages: Fit every page of a PDF onto A4, Letter, Legal, A3, A5 or your own size.
Sign PDF: Draw, type or add a photo of your signature and place it on a page.
Unlock PDF: Type the password once and save a copy that opens without it.
Watermark PDF: Stamp text across your PDF pages.
Word to PDF: Turn a .docx into a PDF with headings, lists, tables and pictures.

Make something

All makers and printables

Worksheets, resumes, certificates, QR codes, calendars, collages and memes.

QR Code Generator: Free QR codes that never expire.
Password Generator: Strong random passwords.
Signature Maker: Draw, type or scan your signature. Download it transparent.
Passport Photo Maker: Size, crop and print passport photos.
Collage Maker: Put 2 to 9 photos in one picture. No watermark, no signup.
Meme Generator: Add classic top and bottom captions to your own picture.
Avatar Generator: Initials on a colour, or a symmetric pattern, from any name. Copy the SVG or download a PNG. Made.
Barcode Generator: Code 128, EAN-13, UPC-A and Code 39 with check digits worked out. Download SVG or PNG. Made in your browser.
Bingo Card Generator: Make up to 100 different bingo cards, with 75-ball numbers or your own words, and download them as a PDF with a caller sheet.
Certificate Maker: Pick one of six templates, fill in the name, text, date and signatures, add your logo, and download a PDF or PNG. Paste a list to make one page per name.
Chart Maker: Type or paste your numbers, pick a chart and download it as SVG or PNG.
Citation Generator: Type the details of a book, article, website, newspaper story or video and get the reference and in-text citation with italics.
Crossword Maker: Type 2 to 40 answers with clues, get a numbered crossword layout, and print the puzzle with an answer key as a PDF.
Email Signature Generator: Fill in your details, pick a layout and copy the signature as formatted text or HTML. Your details stay in your browser.
Favicon Generator: Make a full favicon set from a logo, emoji or letters.
Flashcard Maker: Paste terms and definitions, flip and shuffle cards to study, or print up to 200 cards as a double-sided PDF with cut lines.
Graph Paper: Pick square, dot, isometric, hexagon or polar paper, set the spacing in mm or inches, and download it as a PDF or PNG.
ICS File Generator: Fill in an event, set a time zone, a repeat and a reminder, and download a standard .ics file or a Google Calendar link.
Image Color Palette: Pull 3 to 10 main colours out of any picture.
Invoice Generator: Fill in the form, check the live totals and download an invoice PDF.
Lined Paper: Pick wide, college, narrow, handwriting or Cornell ruling, add a margin line and a colour, and download a page as a PDF or PNG.
Math Worksheets: Make addition, subtraction, multiplication or division worksheets with your number range, stacked or in a row, and an answer key page.
Multiplication Chart: Print a times table chart from 1 to 12 or 1 to 20 with coloured rows, a practice chart with blanks, or a quiz with an answer key.
Online Whiteboard: Draw with a pen, highlighter, shapes, arrows and text on a board you can pan and zoom. Undo and redo, then download a PNG or SVG, or save the board as a file.
Printable Calendar: Pick a month or a whole year, add your logo, a banner photo or a picture for each month, and download the calendar as a PDF.
Resume Builder: Fill in your contact details, jobs, education and skills, reorder the sections, pick one of four single-column templates and download a PDF with real text.
Screenshot Beautifier: Paste a screenshot, make it look good.
Text to Handwriting: Type your text and see it in a handwriting font on lined, grid or plain paper. Pick the ink, size and spacing, then download PNG pages or a PDF.
vCard Generator: Type a contact's name, phones, email, address and birthday, choose vCard 4.0 or 3.0, and download a .vcf file or a QR code.
Word Cloud Generator: Paste text or a list of words with weights, pick a rectangle, circle or heart, and save the word cloud as a PNG or SVG.
Word Search Maker: Type 2 to 30 words, pick a square or rectangular grid and the difficulty, and print the puzzle with an answer key as a PDF.

Text & lists

All text tools

Count, convert, compare and generate plain text.

Word Counter: Count words, characters and reading time as you type.
Case Converter: Change text case instantly.
Remove Duplicates: Paste a list and drop the repeated lines.
Find and Replace: Replace words or patterns in pasted text and see how many changed.
Sort Lines: Paste a list and put it in order: A to Z, Z to A, numeric, by length or natural.
Text Diff: Paste two texts and see what changed.
Add Prefix & Suffix: Put the same text before and after each line of a list.
ASCII Art Generator: Type a word and get big letters drawn with plain characters, in 10 FIGlet fonts. Copy it or download it.
Binary Text Converter: Turn text into 8-bit binary, or binary back into text.
Bionic Reading: Bold the first letters of every word and copy the result as HTML or Markdown.
Caesar Cipher: Shift letters by any number to hide or read a message.
Character Counter: Count characters, letters, digits and bytes, and check SMS parts and a limit.
Compare Lists: Paste two lists and see what is unique to each and what they share.
Delimiter Converter: Turn a comma separated list into lines, lines into a comma list, or any separator into any other.
Emoji picker: Search 1,914 Unicode 17.0 emoji plus skin tones by name and click to copy. Mixed-tone pairs are not included. Nothing you search is sent or saved.
Extract Emails: Paste any text and get its email addresses, one per line.
Extract Numbers: Paste any text and list its numbers with their sum, smallest and largest.
Extract URLs: Paste any text and get its web links, one per line.
Fancy Text: Turn your text into 20 Unicode styles and copy any of them.
Invisible Character: Copy a blank character, such as U+3164 or U+200B, in 1 to 500 copies, and test pasted text for hidden ones.
Keyword Density: Count how often each word and 2 or 3 word phrase appears, with the density as a percentage of all words.
List Cleaner: Trim, drop blanks, drop repeats, sort and fix letter case together.
Lorem Ipsum: Filler text by paragraphs, sentences or words.
Morse Code Translator: Type text for dots and dashes, or paste Morse to read it.
NATO Phonetic Alphabet: Turn text into Alfa, Bravo, Charlie, or code words back into text. Runs in your browser.
Number Lines: Number each line with your own start, step and separator, or strip numbers off.
Online Notepad: A plain text pad that keeps your notes in this browser, with word count, copy and a .txt download. No account needed.
Readability Checker: Paste English text for 6 readability scores and a list of long sentences.
Remove Accents: Paste text with accents and get plain letters back.
Remove Empty Lines: Paste text and delete the blank lines, or squeeze each run down to one.
Remove Extra Spaces: Collapse double spaces, trim line ends and turn tabs into spaces.
Remove HTML Tags: Paste HTML and get the plain text.
Remove Line Breaks: Join wrapped lines into paragraphs and keep the blank lines you want.
Remove Punctuation: Strip punctuation from any text and choose what stays: apostrophes, hyphens, decimals or sentence endings.
Repeat Text: Type something, pick how many copies and what goes between them.
Reverse Text: Flip text backwards, reverse the word order, or turn a list upside down.
Slug Generator: Paste titles, one per line, and get clean URL slugs.
Split Text: Cut text into parts every N characters, every N lines or at a delimiter.
Text to speech: Paste text, pick a voice and press Play. Set speed and pitch, pause and resume. No audio file is made. This page sends nothing; voices marked online may send text to their provider.
Typing Test: Type for 15, 30, 60 or 120 seconds and get net and gross WPM, accuracy and characters per minute.
Word Frequency: Paste text and get a table of words, counts and shares.
Word Unscrambler: Type your letters, with up to 2 blank tiles, and see every word you can make, longest first.

Developer & web

All developer tools

Format, encode, decode and check JSON, tokens, hashes, IDs and timestamps.

JSON Formatter: Format, check or minify JSON.
Regex Tester: Test a JavaScript regular expression: matches, indexes, named groups and a replace preview.
HTML Formatter: Re-indent messy or minified HTML. Choose the indent and line wrap. Runs in your browser.
Text Encoder: Encode and decode Base64, URLs and HTML entities. Handles emoji.
JWT Decoder: Read a JWT's header, claims and expiry.
UUID Generator: Generate random v4 or time-ordered v7 UUIDs.
Bcrypt Generator: Make a bcrypt hash with a cost from 4 to 15, or check a password against an existing hash.
Chmod Calculator: Tick read, write and execute, or type 755 or rwxr-xr-x. Shows the octal mode, symbolic form and the chmod command.
Credit Card Validator: Run the Luhn check, see the card brand and the digit count a number should have, and list public test numbers.
Cron Expression Explainer: Type a crontab line and see it in plain English, field by field, with the next 5 runs.
Crontab Generator: Pick how often a job should run and get the five-field cron line, a plain-English description and the next five run times.
CSS Formatter: Format CSS into readable rules, or minify it. Shows characters before and after. Runs in your browser.
CSV to SQL: Turn CSV into CREATE TABLE and INSERT statements for MySQL, PostgreSQL, SQLite or SQL Server, with guessed column types.
cURL Converter: Paste a curl command and get JavaScript fetch, Python requests, Node axios and Go net/http.
Encrypt Text: Lock text with a password using AES-256-GCM and PBKDF2, get one string to copy, and decrypt it later.
Gitignore Generator: Tick the languages, frameworks, editors and systems you use and get one .gitignore with repeats removed.
Hash Generator: Get SHA-256, SHA-1, SHA-384 and SHA-512 of text or a file.
HMAC Generator: Sign a message with a secret key using HMAC-SHA-256, SHA-1, SHA-384 or SHA-512. Key as text, hex or Base64.
IP Subnet Calculator: Network, broadcast, usable hosts, masks and binary forms for an IPv4 address with a prefix or mask. IPv6 is not supported.
JavaScript Formatter: Re-indent minified or messy JavaScript. Pick indent and brace style. The code is never run.
JSON CSV Converter: Convert JSON to CSV and back.
JSON Diff: Paste two JSON texts and get the added, removed and changed values by path, plus a JSON Patch.
JSON Escape: Turn text into a JSON string and back, with optional \uXXXX for non-ASCII.
JSON to TypeScript: Paste JSON and get TypeScript types plus a matching Zod schema. List items are merged.
JSON YAML Converter: Convert between JSON and YAML in either direction. Errors show the line and column.
JSONPath Tester: Paste JSON and a JSONPath query to see the matched values and their normalized paths. Follows RFC 9535.
Markdown Preview: Type Markdown, see it rendered in a locked-down preview, and copy the HTML.
Markdown Table: Paste rows from a spreadsheet or CSV and get an aligned Markdown table.
Meta Tag Generator: Fill in the fields, copy the head tags, and check an estimated Google result and social card. Nothing is fetched.
Mock Data Generator: Define columns as name: type, pick up to 1,000 rows and copy fake data as JSON, CSV, SQL INSERT or JSON Lines. Email addresses use a reserved example domain.
Number Base Converter: Binary, octal, decimal, hex and bases 2 to 36.
Password Strength Checker: Type a password to see its length, character types, entropy, weak patterns and an illustrative time to guess. Nothing is sent or saved.
Random String: Make 1 to 1,000 random strings of up to 1,024 characters.
Robots.txt Generator: Build a robots.txt with Allow, Disallow, Crawl-delay and Sitemap lines for up to 3 crawlers. Copy it or download it.
Schema Markup Generator: Pick a type, fill in a few lines and get a ready JSON-LD script block, with checks against what Google asks for.
Sitemap Generator: Paste your URLs and get a valid sitemap.xml with escaped characters, no duplicates and a list of problems. Large lists are split.
SQL Formatter: Lay out a SQL query with one clause per line. Pick the dialect and keyword case. Nothing is run.
SRT to VTT: Convert subtitles between SRT and WebVTT, shift the timing and renumber cues.
SSH Key Generator: Make an Ed25519 or RSA SSH key in your browser. Get the OpenSSH public and private files, the SHA256 fingerprint and ready-to-run commands.
SVG Optimizer: Paste SVG code to strip comments, editor data and extra digits. See the bytes saved. The SVG is never drawn or run, and it stays in your browser.
Timestamp Converter: Convert Unix timestamps to dates and back.
Unzip files: Open a .zip file, see every file in it and download one or all. Password-protected entries and zip bombs are refused.
URL Parser: Split a web address into scheme, host, port, path, query and fragment, and list every parameter.
User Agent Parser: See your browser's user agent string and get the browser, engine, OS and kind of hardware from any string.
UTM Builder: Add utm_source, medium, campaign and more to a link. Keeps your existing parameters. Nothing is sent or stored.
XML Formatter: Indent XML with 2 or 4 spaces or tabs, or minify it. Reports the first broken tag by line.
XML to JSON: Convert XML to JSON and back with clear rules for attributes, text and repeated elements.
YAML Formatter: Check YAML and re-indent it, sort keys and set quotes. Errors show the line and column.

AI and LLM tools

All AI tools

Repair AI output, count tokens, check schemas and set up agents.

AGENTS.md Generator: Fill in your project once. Get AGENTS.md, CLAUDE.md, a Cursor .mdc rule with frontmatter and a SKILL.md skeleton, each ready to copy, plus lint notes from the vendors' docs.
AI Tool Converter: Paste one tool or a list in any of five formats. The format is detected, converted to the one you pick, and checked against that vendor's name and schema rules.
Apply Patch: Paste a unified diff and the original text. Get the patched text and a status for every hunk: exact, offset, fuzz or failed, with the reason.
Block AI Crawlers: Pick training only, all AI bots or your own list and copy the robots.txt lines, with each bot's purpose from its operator's own page where there is one.
Context Pack Builder: Add files, a folder or a .zip and get one Markdown, XML or plain-text pack with a file tree and a token estimate.
Cosine Similarity: Paste two vectors, a list of embeddings or two texts. Get cosine similarity, angle, dot product, euclidean distance and norms, or a ranked list.
Exact Math Calculator: Type one expression per line. Get exact fractions, mixed numbers and decimals with repeating digits marked, and no floating-point error.
HTML to Markdown: Paste HTML and get clean Markdown: headings, links, lists, code blocks and tables. Scripts and styles are dropped.
Invisible Characters: Find hidden characters in pasted text, see each one as a code point, and remove or replace them by type.
JSON Repair: Paste almost-JSON from a chat reply, a log or a config. Get strict JSON back and a list of every fix, with line and column.
JSON Schema to Zod: Paste a JSON Schema (draft-07 or 2020-12) and get Zod 4 or Zod 3 code, optional TypeScript types, and a table of the keywords that could not be converted.
JSON Schema Validator: Paste a schema and some JSON and see every error with its path, keyword and message. Draft 2020-12 core rules.
JSON Summarizer: Paste a large API response. Long strings and lists are cut with markers, nulls and empties are dropped, and you see tokens before and after plus an outline of the structure.
JSON to JSON Schema: Paste a JSON example or a list of samples and get a draft 2020-12 schema with types, required keys and formats.
JSONL Validator: Check every line of a JSONL file, turn JSON Lines into a JSON array or a JSON array into JSONL, and check the chat fine-tuning format.
LLM Cost Calculator: Type your tokens per request, request volume and per-1M-token prices to get cost per request, day, month and year.
llms.txt Generator: Build an llms.txt file from a list of pages, or paste one to check its H1, links and sections. Follows the llmstxt.org proposal.
Log Condenser: Strip colour codes and timestamps, collapse repeated lines and keep the errors. See how much shorter the log got.
MCP Config Generator: Enter a server once. Get the config entry for your client, the file path for macOS, Windows and Linux, and a warning if a secret would end up in plain text.
OpenAPI to AI Tools: Paste an OpenAPI 3.0 or 3.1 spec as JSON or YAML. Each operation becomes one tool with merged parameters, resolved references and a clear list of what was left out.
Prompt Cache Analyzer: Paste two API request bodies. See the first block that changed, the shared prefix size and whether it meets the minimum cacheable length.
Prompt Injection Scanner: Paste web page text, tool output or a document. See instruction overrides, hidden characters, data-leaking links and encoded text, with line and column.
Prompt Template Tester: Paste a prompt with {{var}}, {var} or ${var} placeholders and your values. See the rendered prompt, missing and unused variables, and a token estimate.
Redact Secrets: Paste logs, config or a prompt and replace API keys, tokens, passwords, emails and card numbers before you share it.
Remove Markdown: Strip asterisks, hashes, links and tables from ChatGPT or Markdown text. Choose how bullets, links and tables come out.
Retrieval Evaluation: Paste ranked results and the relevant ids for each query. Get precision@k, recall@k, MRR, MAP, nDCG@k and hit rate per query, or compare two runs side by side.
Schema Strict Mode: Paste a JSON Schema. Get a version the chosen API accepts, a list of every change by JSON Pointer path, and warnings for rules that cannot be kept.
Shell Command Checker: Paste a bash or zsh command from a chat, a README or an AI agent. See what each part does and which parts are risky, with a reason for each.
Shell Escape: Quote one string or a list of arguments for five shells, and see how each shell splits the result, so you know it reads back unchanged.
SKILL.md Validator: Paste an agent skill, a Cursor .mdc rule or an AGENTS.md. Get errors and warnings with line numbers, checked against the published rules.
Text Chunker: Split text by characters, words, approximate tokens, Markdown headings or paragraphs, with overlap. Copy the chunks or a JSON array.
Token Counter: Paste text to get the exact token count for OpenAI's o200k_base encoding, see where it is cut, and check it against context sizes.
Tool Call Validator: Paste an Anthropic, OpenAI Chat or OpenAI Responses conversation. Get a list of broken tool_use, tool_calls and result pairs with the message index.
Tool Schema Linter: Paste tools from OpenAI, Anthropic, Gemini or MCP, even from several servers. Get name errors, weak descriptions, schema mistakes, name collisions and a token estimate per tool.
Unified Diff Checker: Paste a unified diff to check its hunk headers and line prefixes, get a corrected diff and apply it to your file.

Calculators & dates

All calculators

Work out percentages, ages, dates and ratios.

Percentage Calculator: Five percentage calculators with the working shown.
Loan Calculator: Monthly payment, total interest and a payment table for a fixed-rate loan.
Tip Calculator: Work out the tip, the total and each person's share.
Age Calculator: Age in years, months and days (calendar months), on any date.
BMI Calculator: Work out BMI from height and weight in cm and kg, or ft, in and lb.
Date Calculator: Add or subtract years, months, weeks and days to a date.
Alarm Clock: Set a time, add a label, pick a sound and snooze 5 or 10 minutes. It rings only while this tab stays open.
APR Calculator: Turn a loan's rate and fees into its APR and effective annual rate, with a payment schedule.
Aspect Ratio: Find a ratio, or the missing width or height.
Average Calculator: Paste a list of numbers and get the mean, median, mode, range and sum. Exact arithmetic,.
Body Fat Calculator: Estimate body fat from neck, waist and height measurements, in cm or inches.
Break-Even Calculator: Find the units and revenue needed to cover fixed costs, and the units for a target profit.
Business Days Calculator: Count working days between two dates, or add working days to a date.
CAGR Calculator: Find the CAGR from a start and end value, or the future or start value from a rate.
Calorie Calculator: Work out BMR, daily maintenance calories and calories for a weight goal.
Compound Interest Calculator: Final balance, total contributions and interest with compounding and regular deposits.
Concrete Calculator: Work out how much concrete a slab, footing or round column needs in yd³, m³ and ft³, plus the number of premix bags.
Confidence Interval Calculator: Enter a sample mean, standard deviation and size, or a count out of a sample, for the interval, margin of error and critical value at 80 to 99.9 percent.
Countdown Timer: Set hours, minutes and seconds, press Start. It rings at zero and stays right in a background tab.
Currency Converter: Convert between 165 currencies with Frankfurter blended reference rates, today or on any date since 1999. Your amount stays.
Days Until: See how many days, weeks and working days are left until a date or holiday.
Debt Payoff Calculator: Compare the snowball and avalanche methods across several debts, with a payoff date and total interest.
Debt-to-Income Calculator: Work out your front-end and back-end debt-to-income ratio and what would bring it down.
Depreciation Calculator: Straight-line, declining balance, sum-of-the-years' digits and units of production, with a yearly schedule.
Discount Calculator: Find the sale price and what you save, with a second discount and tax.
Dog Age Calculator: Convert a dog's age to human years with the 2020 epigenetic formula and a size-based rule of thumb.
Due Date Calculator: Find your estimated due date, how far along you are today and the milestone dates.
Electricity Cost Calculator: Work out kWh and the cost per day, month and year for any appliance, with optional standby power.
FD Calculator: Work out a fixed deposit's maturity amount, interest and yield, with a table by year.
Final Grade Calculator: Find the score you need on the final exam to reach a target grade, with a table for 90, 80, 70 and 60 and a what-if score.
Fraction Calculator: Add, subtract, multiply or divide fractions, mixed numbers and decimals. Get the simplified fraction, mixed number and decimal with the steps.
Gas Mileage Calculator: Turn distance and fuel used into MPG (US and UK), L/100 km and km/L, or price a trip.
GCD and LCM: Find the greatest common divisor (HCF) and least common multiple of 2 to 20 whole numbers, with Euclid steps and prime factors.
GPA Calculator: Work out a semester GPA from grades and credits, with the scale shown.
Grade Calculator: Work out a weighted course grade, or the score you need on the final.
Gravel Calculator: Work out how much gravel, crushed stone, sand, topsoil or mulch an area needs, in yd³, m³, weight and bags.
GST Calculator: Convert GST-exclusive to GST-inclusive prices and back, with an optional India invoice layout: CGST and SGST, or IGST.
Home Affordability Calculator: Find the home price your income and debts support at editable debt-to-income limits.
Ideal Weight Calculator: See the ideal weight for your height by four classic formulas, next to the weight range for a BMI of 18.5 to 24.9.
Inflation Calculator: What an amount from one year is worth in another, using official US, UK or Canadian price data.
Interval Timer: Work and rest rounds with beeps, round counts and total time left. It stays right in a background tab.
Logarithm Calculator: Find log base b of x, solve b^y = x for x or for the base, and see the change-of-base steps.
Macro Calculator: Turn daily calories into grams of protein, carbs and fat, per day and per meal, for a diet style and goal.
Margin Calculator: Give any two of cost, price, margin and markup and get the rest, with the profit.
Matrix Calculator: Add, subtract and multiply matrices, or find a determinant, inverse, rank, RREF or power, up to 6 × 6, in exact fractions with the row operations shown.
Mortgage Calculator: Monthly mortgage payment with property tax, insurance and other costs, plus a yearly payment table.
Ohm's Law Calculator: Type any two of voltage, current, resistance and power to get the other two, with unit prefixes and the Ohm's law wheel.
One Rep Max Calculator: Estimate your one-rep max from the weight and reps of a set, with four formulas and a table of percentages.
Ovulation Calculator: Estimate your ovulation day, fertile window and next period from your last period and cycle length.
Pace Calculator: Work out pace, finish time or distance, with splits and race predictions.
Paint Calculator: Work out litres or gallons of paint for your rooms, minus doors and windows, with coats, ceilings and can sizes.
PayPal Fee Calculator: Work out the PayPal fee on a payment, or the amount to ask for so you receive what you want.
Permutation and Combination: Count ordered arrangements (nPr) and unordered choices (nCr), with or without repeats, as exact whole numbers. List the sets when n is 8 or less.
Pomodoro Timer: Focus 25 minutes, break 5, long break 15 after four sessions. All lengths editable, with a session count.
PPF Calculator: Maturity value, interest and a year-by-year table for a PPF account, in rupees with lakh and crore grouping.
Prime Number Checker: Check whether a whole number up to 10^15 is prime, see its factors, and find the previous and next prime.
Probability Calculator: Work out P(A and B), P(A or B), the chance of at least one success in n tries, binomial odds and odds to probability.
Pythagorean Theorem Calculator: Enter two sides of a right triangle to find the third, with steps, exact radicals and a labelled diagram.
Quadratic Formula Calculator: Solve a quadratic equation with steps: discriminant, roots, vertex and factored form.
Ratio Calculator: Simplify a ratio to lowest terms, solve a proportion a:b = c:x, or split a total in a ratio. Exact, with steps.
Rent vs Buy Calculator: Compare owning a home with renting and investing the difference, with a break-even point and a year-by-year table.
Resistor Color Code Calculator: Read resistor color bands as ohms with tolerance, or turn a value into colors, with a drawing and the nearest E-series value.
Retirement Calculator: Project your savings at retirement, the monthly income they can pay and how long they last.
ROI Calculator: Work out ROI, the gain or loss and the annualised return from what you put in and got back.
Salary to Hourly: Turn a yearly, monthly, weekly, daily or hourly pay into every other period.
Sales Tax Calculator: Add sales tax to a price or take it out of a total. Type one or two rates.
Sample Size Calculator: Find how many responses a survey needs for your confidence level and margin of error, or the margin for a sample you have.
Savings Goal Calculator: Find the monthly deposit that reaches a goal in a set time, or how long a set deposit takes.
Scientific Calculator: Trig, logs, roots, powers, factorials and brackets, with a keypad or your keyboard and a clear message for every error.
Scientific Notation Converter: Paste numbers, one per line, and convert them between decimal, scientific, engineering and E notation, with no digits lost on long numbers.
Significant Figures Calculator: Count the significant figures in a number, round to a set number of them, or add, subtract, multiply and divide with the sig fig rules, with each rule explained.
Simple Interest Calculator: Interest and total from principal, yearly rate and time in years, months or days.
SIP Calculator: Estimate the value of a monthly investment plan, with an optional yearly step-up.
Sleep Calculator: Find a bedtime for the time you must wake up, or a wake-up time for when you go to bed, in whole sleep cycles.
Slope Calculator: Find the slope as an exact fraction, plus the line equation, intercepts, angle, distance, midpoint and a graph.
Split Bill Unevenly: Share a bill by what each person ordered or by shares, with tax and tip shared in proportion.
Square Footage Calculator: Add up to 10 rectangles, triangles, circles and trapezoids and get the total area in square feet, metres, yards, acres and hectares.
Square Root Calculator: Find square roots, cube roots and nth roots to up to 100 exact decimal places, with radical form.
Standard Deviation: Paste numbers, choose population or sample, and get the standard deviation, variance and a steps table. Exact arithmetic.
Stopwatch: Start, pause and record laps. It follows the clock, so a background tab stays right.
Tile Calculator: Work out how many tiles and boxes a floor or wall needs from its size, the tile size, the grout gap and the waste.
Time Calculator: Add and subtract a list of durations, or turn hours and minutes into decimal hours.
Time Card Calculator: Add up a week of shifts with breaks and overnight hours, then split overtime and pay.
Time Duration Calculator: Work out the hours between two times, with a break and a rate, or add time to a time.
Triangle Calculator: Enter any three of sides a, b, c and angles A, B, C to solve the triangle, with steps and a drawing to scale.
Unit Price Calculator: Compare the price per unit of two to four items and see which is cheapest.
VAT Calculator: Add VAT to a net price or remove it from a gross price. Type a rate or pick a common one.
Watts to Amps Calculator: Convert watts to amps, amps to watts, find volts or use Ohm's law, for DC, single-phase and three-phase.
Week Number Calculator: Find the ISO week number of any date, the US-style week and the day of the year.
Z-Score Calculator: Turn a value, mean and standard deviation into a z-score, or turn a z-score or percentile back into a value, with left, right and between probabilities.

Converters

All converters

Units, time zones, colours and numbers in words.

Unit Converter: Convert length, weight, temperature and more as you type.
Time Zone Converter: Convert a time between zones. Handles daylight saving.
Number to Words: Write any amount in words for cheques and documents.
Roman Numerals: Convert numbers to Roman numerals and back, with a symbol-by-symbol breakdown. Strict standard form, optional bracket notation for large numbers.
CSV to Excel: Turn CSV or TSV into an .xlsx workbook with bold headers, set column widths and leading zeros kept.
Cups to Grams: Turn cups, tablespoons and teaspoons of flour, sugar, butter and more into grams and ounces, or grams back into cups.
Excel to CSV: Turn any sheet of an .xlsx workbook into CSV, with real dates and one file per sheet.
Military Time Converter: Convert military time such as 1430 hours to 2:30 PM and back, many lines at once, with a chart of all 24 hours.
Shoe Size Converter: Convert shoe sizes between US men's, women's and children's, UK, EU, Japan and Mondopoint, from a size or a foot length.
World Clock: See the live time in cities you choose, the difference from your own zone and the hours when working days overlap.

Sports & teams

All sports tools

Fixtures, brackets, scores and team lists.

Bracket Generator: Single or double elimination brackets with byes and seeding. Entries stay.
Round Robin: Paste your teams and get every round, home and away.
League Table: Paste match results and get the standings for any sport.
Scoreboard: Big tap-to-score numbers for two to four sides, with sets, undo and full screen.
Draft Order: Paste team or manager names, pick snake or linear, and get every pick for every round.

Design & colour

All design tools

Palettes, gradients and colour checks.

Gradient Generator: Build a linear, radial or conic gradient with up to 5 color stops and copy the CSS.
Color Palette Generator: Build color harmonies from one base color: complementary, analogous, triadic and more.
Color Converter: Convert HEX, RGB, HSL and CMYK and check contrast.
Box Shadow Generator: Set offset, blur, spread, color and opacity for up to 3 shadow layers and copy the CSS.
Border Radius Generator: Round all corners at once or one by one, in px or %, with optional elliptical corners.
PX to REM Converter: Convert px to rem or em and back at any base font size, one value or a whole list.
Clip-path Generator: Pick a polygon, circle, ellipse or inset, drag the points on a live preview and copy the clip-path rule.
Contrast Checker: Check text and background colors against WCAG 2.x AA and AAA, with a live preview and a passing color suggested.
CSS Grid Generator: Set columns, rows, track sizes, gaps and named areas, then copy the grid CSS and a child placement example.
Flexbox Generator: Pick direction, wrap, justify, align and gap, then copy the flex CSS with a table of what each value does.
Glassmorphism Generator: Set blur, transparency, border and shadow for a frosted glass panel and copy CSS with a fallback.
Tint and Shade Generator: Make lighter tints and darker shades of one color, in 3 to 10 steps or a 50 to 900 scale.

Audio, video and device tests

All media tools

Test your mic, webcam, keyboard and screen, or record audio and your screen.

Audio Converter: Turn WAV, M4A, OGG, FLAC or MP3 into MP3 or WAV. Pick the bitrate. Files stay.
Audio Joiner: Put 2 to 20 audio files in order, add a crossfade if you like, and save one MP3 or WAV.
CPS Test: Click as fast as you can for 1, 5, 10, 30 or 60 seconds and see your clicks per second.
Dead Pixel Test: Fill your screen with black, white, red, green, blue and grey to spot dead and stuck pixels. No flashing.
Guitar Tuner: Play a string and see its note and how many cents sharp or flat it is. Five tunings, a chromatic mode and reference tones.
Keyboard Tester: Press keys and watch them light up on a 104-key layout. See key codes and how many keys you can hold at once.
Metronome: Set 20 to 300 BPM, pick a time signature, add subdivisions and tap in a tempo. Every click is timed on the audio clock.
Mic Test: See your microphone level live, then record 5 seconds and play it back.
MP3 Cutter: Load a song or recording, drag the handles on the waveform, add a fade and save the part you want as MP3 or WAV.
Reaction Time Test: Wait for the screen to turn green, then click as fast as you can. Five tries, your average in milliseconds, false starts caught.
Screen Recorder: Record a tab, a window or your whole screen in the browser, with optional sound and microphone.
Screen Resolution: See your screen size, pixel ratio, viewport and colour depth, with a summary you can copy.
Video to GIF: Pick a start and up to 15 seconds of an MP4, MOV or WebM video, choose frames per second and width, and save an animated GIF.
Video to MP3: Pull the sound out of an MP4, MOV, WebM or MKV video and save it as MP3. Pick the bitrate.
Voice Recorder: Record your voice in the browser, pause and resume, play it back and download the file.
Webcam Test: See your camera live, check the real resolution and frame rate, and save a snapshot.

Games

All games

Sudoku, Bottle Brain, Snake, Hangman and Cascade.

Sudoku: Play interactive Sudoku puzzles.
Bottle Brain: Guess the hidden colour order.
Arcade Games: Play Snake, Hangman and Cascade.
Crossword Puzzle: A new random crossword every time, or the daily crossword. Three sizes, check and reveal, a timer, and progress saved in your browser.