PDF Tools

20 free PDF utilities, all running entirely in your browser. No uploads, no accounts.

How these PDF tools work

Every PDF tool on this page runs entirely inside your web browser using WebAssembly and the PDF-lib library. When you select a file, it is loaded into memory on your device and processed there — nothing is transmitted to a server. This means your documents stay private by design, not just by policy.

Most PDF operations complete in under a second for typical file sizes. Merging, splitting, compressing, rotating pages, adding passwords, and watermarking all happen client-side. For compression specifically, the tool removes redundant embedded resources and re-encodes images at a lower quality level while keeping the document readable. The result is a smaller file that opens normally in any PDF viewer.

Password protection uses AES-256 encryption, the same standard used by banks and government agencies. Once a password is set, the file cannot be opened or edited without it. The unlock tool works by verifying the password you supply and then producing an unencrypted copy — it does not brute-force anything and requires the correct password.

Frequently Asked Questions

Are all 20 PDF tools free?
Yes: no account, no watermarks on output, no file count limits. Every PDF tool here is genuinely free.
Do my PDFs get sent to a server?
No. AlteredIdea uses pdf-lib compiled to WebAssembly, so your file is processed inside your browser tab. Nothing is uploaded.
Is there a file size limit?
We don't set one. Your browser's memory is the practical ceiling. Most users handle files up to a few hundred MB without issues; very large files may slow things down a bit.
Why does my laptop fan spin up when processing a big PDF?
Because your CPU is doing the work instead of a remote server. That's intentional: it's the trade-off for keeping your files private. For large PDFs, expect a few seconds of heavy lifting.
Can I use these tools on iPhone or Android?
Yes. Safari on iPhone and Chrome on Android both work. You can upload from your Files app or Photos app. Some tools like the PDF editor are more comfortable on a bigger screen, but they all run on mobile.
Can I process a password-protected PDF?
Most tools need the file to be unlocked first. Use the Password Unlock tool (you'll need the current password), then run it through whatever else you need.