Compare PDF Files Free Online — Highlight Differences Instantly
Upload two PDF versions and see every addition, deletion, and change highlighted side by side. Green for added text, red for removed, yellow for modified lines. No signup, no upload — runs entirely in your browser.
Compare PDF Files
Upload both PDFs — differences highlighted instantly in a side-by-side view
Original PDF
Drop or click to upload
Modified PDF
Drop or click to upload
🔍Compare PDF Files — How This Tool Works
When you have two versions of a document — a contract before and after negotiation, a report draft and its final form, a policy document that may have been quietly changed — you need to know exactly what is different. Reading both documents side by side and spotting every change manually is slow, error-prone, and misses small wording changes entirely.
This tool uses PDF.js to extract the text content from both PDFs page by page. It then runs a diff algorithm comparing the lines, identifying which lines were added, which were removed, and which were modified. Results appear in a colour-coded side-by-side panel: green for text that was added in the modified version, red for text that was removed from the original, and yellow for lines where content changed. With word-level diff enabled, even small inline word changes are highlighted within the line itself.
Upload Both PDFs
Drop the original PDF on the left and the modified version on the right. Both load locally — nothing is uploaded.
Set Options
Choose whether to ignore case differences, ignore extra whitespace, and whether to enable word-level diff highlighting within changed lines.
Compare
Click Compare PDFs. Text is extracted from both files and the diff runs instantly across all pages.
Review & Download
Navigate page by page through the side-by-side diff. Download a plain text report of all differences found.
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