Everything here runs on your device. Your files and text are not uploaded.
These tools work on PDF documents inside your browser. Common jobs are joining a scanned ID, a signed form and a cover letter into one file, pulling pages 3 to 7 out of a long report, putting pages in the right order or turning a sideways one upright, adding page numbers or a DRAFT stamp, shrinking a scan so it fits an email, copying the text out of a report, turning each page into a JPG for a website that does not accept PDFs, or building one PDF from a set of phone photos.
A PDF is read into memory, its pages are copied or drawn by two open-source libraries, pdf-lib and PDF.js, and a new file is written for you to download. Nothing is sent to a server, which matters for contracts, tax forms and identity documents. Merging, splitting and organizing copy pages as they are, so text stays text and images are not compressed a second time. Compress PDF is the exception: it turns every page into a picture so that scans get much smaller, and the text in the result can no longer be selected.
Some limits are worth knowing. A PDF that is locked with a password is refused with a message, so remove the password in your PDF reader first and add the unlocked copy. Very large documents, such as a 300-page scan, need a lot of memory on a phone and may be slow. Bookmarks are dropped when files are merged, and fillable form fields may stop being fillable. Page ranges use one format: 1-3, 5, 8-10 selects pages 1 to 3, page 5, and pages 8 to 10. PDF to Text reads text that is stored in the file, so a scan with only pictures of pages gives nothing.
Yes. Add two or more files, drag them into order, and the browser joins them locally. Merging ten PDFs of 2 MB each produces a single file of about 20 MB that you save from the page.
The tool refuses it with a message and does not try to unlock it. Open the file in a PDF reader you trust, save a copy without the password, and add that copy. This applies to every PDF tool here.
No. Pages are copied with their text, fonts, images, size and rotation, so an A4 page stays A4 beside a US Letter page. PDF to JPG is different: it draws each page as a picture at the resolution you pick, such as 150 or 300 DPI.
Compress PDF turns every page into a JPEG picture and rebuilds the file from those pictures, so the letters are pixels, not text. It suits scans and photo PDFs. If the PDF is made of real text, the result can be larger than the original, and the tool tells you first; you get the bigger picture-only copy only if you ask for it.