Compare two PDFs online
Find out exactly what changed between two versions of a document — a contract redline, a report draft and its final version, anything where "did they actually change section 4?" matters more than trusting a memory of it.
This compares the text of both files, line by line, and reports what was added and what was removed — the same idea behind any code diff tool, applied to a PDF's extracted text instead of source code.
Your files never leave your device. Comparison runs entirely in your browser, so nothing is uploaded, stored, or scanned.
or drop them here — nothing is uploaded
How to compare pdf
Add both PDFs
Drop the two files into the box, in either order — add the older version first for a report that reads naturally.
Compare and download
Press Compare PDF. A report downloads showing every line added or removed.
Frequently asked questions
Are my files uploaded anywhere?
No. Comparison runs in your browser using JavaScript, so your files stay on your device. You can confirm this by opening your browser devtools Network tab while working — there are no upload requests.
Does this compare the visual appearance, or the text?
The text only. Two pages that read identically but differ in font, colour, or exact layout will show as no differences, because this never looks at pixels — it extracts each PDF's text and compares that. For a visual, pixel-level comparison, this is not the right tool.
What does the report look like?
A plain text file in the familiar diff style: unchanged lines shown plainly, added lines prefixed with a plus sign, removed lines prefixed with a minus sign — the same convention `git diff` and most code-comparison tools use.
Why does a small wording change show as a whole line added and removed?
Because the comparison works at the level of a whole reconstructed line, not individual words — changing even one word inside a line means that line no longer matches, so it shows as the old line removed and the new line added, rather than highlighting just the changed word.
Can this compare very long documents?
Most documents, yes — very long ones can hit a limit, since comparing every line of one document against every line of the other gets computationally expensive as both grow. If a comparison is refused as too large, try a page range at a time instead.
Can this compare a password-protected PDF?
Not directly — unlock it first, using a password you know.