Spot changes between versions. Everything runs locally in your browser — your files are never uploaded to a server, no registration is required, and the tool is completely free.
How to Compare PDF
Add both versions of the document — the original first, then the revision.
Run the comparison; each page is rendered and checked pixel by pixel.
Read the summary: which pages changed, or confirmation that none did.
Download the result, where every changed area is highlighted in red.
Features
Catches What a Text Diff Misses: Comparison happens on rendered pixels, not extracted text, so a moved table, a swapped logo, a different figure inside an image or a substituted font all show up. A text-only diff sees none of those.
Marks the Changes on the Page: The output is a normal PDF of the revision with differing regions tinted red, so you can review it in any reader instead of trusting a similarity score.
Handles Different Page Counts: Pages that exist in only one of the two documents are reported as added or removed rather than being flagged as one enormous change.
Both Files Stay Local: Contract revisions and draft agreements are exactly the documents you should not be uploading to compare. Neither file leaves your browser.
Frequently asked questions
Why compare images instead of text?
Because most changes that matter are not word substitutions. A figure moved into a different column, a replaced signature block, or a chart redrawn with new numbers are invisible to a text diff but obvious in a pixel comparison.
It says pages changed but they look the same to me.
Look closely at spacing and glyph shapes. A font substitution or a shift of a fraction of a millimetre is a real difference in the file even if it reads identically. Very small ratios usually mean exactly that.
Does a scanned document compare reliably?
Less so. Two scans of the same page differ in noise, skew and exposure, which registers as change. It works best on digitally generated PDFs.
Which document does the output show?
The second one you added — the revision — with the differences highlighted on it.