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Compare two PDF files

View two versions side by side with every insertion, deletion and change highlighted automatically.

Runs in your browser Free, no signup No file uploaded
Select PDF files

or drop them here — as many as you like

Working…

Processing on your device — nothing is being uploaded.

How to use Compare PDF

  1. Add your file by dragging it onto the box above, or click to browse your device.
  2. Adjust the settings if you need something other than the defaults.
  3. Press the Compare PDF button and wait a moment while it processes.
  4. Your finished file downloads automatically. You can also download it again from the result panel.

Is it private?

This tool runs entirely inside your browser. When you select a file it is read straight into your tab's memory and processed on your own machine using WebAssembly. Nothing is uploaded, nothing is stored on a server, and nothing is logged. You can verify this yourself: open your browser's network inspector and run the tool — you will not see your document leave your device. Once you close the tab it is gone.

What it costs

Nothing. There is no account to create, no daily limit on how many files you can process, no cap on file size beyond what your own device can handle, and no watermark added to your output. The site is funded by advertising, which keeps the tools themselves free for everyone.

Good to know

Because compare pdf happens on your own hardware, speed depends on your device rather than on how busy our servers are. A modern laptop will handle most documents almost instantly. Very large files — several hundred megabytes, or documents with thousands of pages — will take longer and use more memory, so on a phone it is worth closing other tabs first.

If a file fails to open, it is usually because it is password protected or was damaged in transit. Remove the password with Unlock PDF, or try Repair PDF to recover a corrupted document.

Frequently asked questions

Is Compare PDF free to use?
Yes, completely. There is no account to create, no trial period and no daily limit on the number of files you can process. We do not add a watermark to anything you produce.
Do my files get uploaded to a server?
No. This tool runs entirely in your browser using WebAssembly, so your file never leaves your device. You can confirm this by opening your browser's network inspector while the tool runs — no file transfer takes place.
Is there a limit on file size?
We do not impose one. The practical limit is your device's available memory. Desktop browsers routinely handle files of several hundred megabytes; on a phone, very large documents may run out of memory.
Which browsers are supported?
Any current version of Chrome, Edge, Firefox, Safari, Opera or Brave, on desktop or mobile. No plugin or extension is needed and nothing is installed.
Will the quality of my document change?
No. Unless you are deliberately using a tool that reduces quality — such as compression, where you choose the trade-off yourself — the original content, fonts and images are preserved exactly as they were.

Related tools

Other things you can do in pdf security.

Protect PDF

Encrypt your document with a password and set permissions for printing, copying and editing.

Unlock PDF

Remove restrictions with no password at all, or recover a lost open-password automatically. Everything runs on your device.

Redact PDF

Permanently remove confidential text and images. The content is destroyed, not just covered over.

Edit Metadata

Inspect hidden document properties and wipe author, software and timestamp data before you share.