Compare PDF
Compare PDF shows both documents next to each other and outlines the regions that changed, all rendered locally with pdf.js. Jump between differing pages, tune the sensitivity, and read the difference count. Great for proofing revisions.
Drop PDF A here or click to browse
Drop PDF B here or click to browse
Files stay in your burrow: everything is processed on your device, never uploaded.
How to use this tool
- 1Drop the original PDF (A) and the revised PDF (B).
- 2The tool renders matching pages side by side and scans them for differences.
- 3Coral boxes outline changed regions on both sides; tune sensitivity if small shifts matter.
- 4Page through the documents or jump straight to the next differing page.
FAQ
What exactly counts as a difference?
It is a pixel comparison, not a text diff. Both pages are rasterized, and regions whose average brightness changes more than the sensitivity threshold are flagged. You see what the eye would see, so a one-pixel shift or a tiny punctuation change may pass below the threshold.
Can it compare PDFs with different page counts?
Yes. Pages beyond the shorter document are treated as differences, and the summary tells you both counts. The comparison runs up to the longer document.
Does it produce an output file?
No. This is a review aid: the comparison happens on screen, in your browser. If you need to send the result to someone, take a screenshot of the highlighted pages.