Compare PDFs
See exactly what changed between two versions of a document, down to the word.
Compare two PDFs for free in your browser. The pages are lined up first, so inserting one page into a contract shows as one page added rather than turning every page after it red. Then the words are compared, and the exact stretches that changed are boxed on both copies side by side. You can download the new version with the changes highlighted. Nothing is uploaded: two versions of a contract are exactly the pair you should not be sending to a server.
When this is worth doing
- A contract came back from the other side and you need the clause they touched
- Checking a supplier's revised quote against the one you agreed
- Confirming that a signed copy matches the version you sent
- Finding what an editor changed in a document you wrote
- Working out which version of a report is the later one
- Proving a document has not been altered since you last saw it
What you get
- ✓Pages Matched First - An inserted or deleted page reads as exactly that, instead of flagging every page after it. A page that simply moved is reported as moved
- ✓Down To The Word - The exact stretches that changed are boxed on both copies, not the whole paragraph they sit in, so you can see the edit rather than hunt for it
- ✓It Admits What It Cannot Compare - A scanned page has no text in it. This says so instead of reporting no differences, which is the one wrong answer a comparison tool must never give
- ✓Neither File Leaves Your Device - Two versions of a contract are exactly the pair you should not be uploading. All of this runs in your browser
Privacy First:
Both PDFs are read and compared inside your browser. No upload, no server, no copy kept anywhere. Close the tab and nothing remains.
Questions about comparing PDFs
What happens if a page was inserted or deleted?
It is reported as one page added or removed, and the pages around it are left alone. That is the whole reason the pages are matched to each other before anything is compared: a tool that pairs page 2 with page 2 turns a single insertion into a document where everything after it looks rewritten, and the change you were actually looking for is lost in the noise.
Can it compare scanned documents?
Not usefully, and it will tell you so rather than pretend. A scan is a picture of text, with no text in it to compare, so those pages are counted separately and reported as not compared. Run them through the OCR tool first to give them a text layer, then compare the results.
Does it notice formatting changes?
No. This compares what the documents say, not how they look, so a paragraph moved down the page or set in a different font reads as unchanged. That is deliberate: for contracts and reports the words are the thing, and a comparison that lights up because the margins moved is one nobody can use.
What does the downloaded file contain?
Your revised PDF exactly as it was, with a highlight drawn over each stretch that changed. It is a normal PDF, so you can send it to whoever has to approve the changes and they see them without needing this tool.
How big a document can it handle?
A 300 page document takes well under a second to read and match. Pages are only drawn when you look at them, so the size of the file does not decide how long you wait. A single page rewritten from end to end is reported as changed throughout rather than marked word by word, which keeps a pathological page from freezing the tab.
Are my files uploaded?
No. Both files are read, matched and compared inside your browser, and the marked up copy is written there too. Nothing is sent anywhere, which matters more here than almost anywhere else on this site: if you are comparing two versions of an agreement, those are two documents you have every reason not to hand to a server.
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Once you know what moved, use Organize PDF to put the pages back in order, or Redact to take something out.