About ModifyPDF

ModifyPDF is a free collection of PDF tools: merge, split, compress, convert, edit, sign, protect and more. What makes it different is where the work happens: in your browser, on your own device.

Who runs it

ModifyPDF is built and run by Jason Nel of Jaytec, an independent web developer in South Africa. Bug reports and corrections sent to [email protected] go straight to the developer.

How it works

When you choose a file, it’s read into your browser’s memory and processed with open-source libraries (pdf-lib and Mozilla’s PDF.js). The result is saved straight back to your device. Your documents are never uploaded to our servers, so we couldn’t read them even if we wanted to.

What you can expect from each tool

Every tool page explains what the tool does and what it doesn’t, in plain language. If a conversion can’t carry something over (for example, editable text from a scanned page) or an option has a trade-off (such as image quality at the strongest compression level), the page says so, so you know what to expect before you start.

The guides are written to answer a real question completely, with steps you can follow in ModifyPDF and, where it helps, in the software you may already have, such as Microsoft Word or Preview on a Mac. If you spot a mistake, please tell us and we’ll correct it.

What you can do here

  • Organize: merge, split, reorder, rotate, extract and remove pages.
  • Make files smaller: compress a PDF by level or down to a size limit such as 200 KB or 1 MB.
  • Convert: PDF to and from Word, Excel, JPG, PNG and text, plus HEIC, TIFF and WebP images to PDF.
  • Edit and sign: add text and images, sign, redact, watermark, number pages, crop and fill in forms.
  • Protect: add or remove a password and strip hidden metadata.
  • Official forms: fill in IRS forms such as the W-9, W-4, 1099-NEC, SS-4 and W-7 on the blank PDF published by the IRS.

How we check our work

Before a tool is published it is run on real documents: scans, forms, statements, files made in Word and files made by phone apps. For conversions, the output is opened in the program it is meant for, such as Microsoft Word or Excel, and compared with the original. Pages about official forms are checked against the form and the instructions published by the agency that issues it, and they say which revision of the form is provided.

What we don’t do

We don’t keep copies of your files, because we never receive them. We don’t ask you to create an account, we don’t add watermarks, and we don’t guess or crack passwords: Unlock PDF only works when you know the password. Our pages about tax forms explain the form; they are not tax advice.

Why it’s free

ModifyPDF is supported by advertising. There are no accounts, subscriptions, usage limits or watermarks.

Guides

Alongside the tools we publish practical PDF guides, such as how to redact a document properly or shrink a file for email.

Contact

Questions, bug reports or ideas for new tools are welcome. See the contact page or email [email protected].