Compare PDF
Two versions of a document: which one changed? Get a page-by-page text diff between two PDFs as a clean report, generated entirely in your browser.
Files processed in your browserSelect two PDFs or drag & drop
Original first, revised second
Your files never leave your device. Compare PDF runs entirely in your browser using JavaScript. Nothing is uploaded to a server. When you close this tab, your file is gone from memory.
How to compare pdf
- Select two PDFs. Pick the original and the revised version of the document.
- Compare. The text of both files is extracted page by page and diffed in your browser.
- Read the report. Download a plain-text report: removed lines marked -, added lines marked +, page by page.
Want more detail? Read our full guide: How to compare two PDF files.
Why compare two PDFs?
Documents rarely change all at once. A contract comes back marked "final" after a round of edits, a policy is reissued with a "minor revision," a proposal returns from a colleague who swears they only tweaked one clause. The wording that actually moved is what matters, and it is exactly what a quick read tends to miss: a single altered figure or a flipped "not" can hide in plain sight among pages that look unchanged.
Checking by eye does not scale. Opening both versions in side-by-side windows and scrolling in lockstep is slow, and concentration slips somewhere around page five. This tool removes the guesswork: it extracts the text of both files page by page and runs a real line-by-line diff, then produces a plain-text report that marks removed lines with a minus and added lines with a plus, organised page by page, with the page counts of the two files compared up front.
The first file you choose is treated as the original and the second as the revision, so the plus and minus markers read in the direction you expect; swap the order before comparing to flip it. A report like this is easy to skim, easy to archive as a record of what changed between drafts, and easy to forward to whoever needs to sign off.
It is worth knowing this is a text comparison, not a visual one. If an image is swapped, or a paragraph moves to a different page but keeps the same words, the diff will not flag it. For those cases a side-by-side look still helps. Everything is parsed and compared inside your browser, which means confidential contracts and unreleased documents are never uploaded anywhere.
Frequently asked questions
Are my files uploaded?
No. Both files are parsed and compared entirely in your browser.
What exactly is compared?
The text content, page by page: each page's lines are matched with a diff algorithm, so added, removed and changed lines are identified. Page counts are compared too.
Does it detect image or layout changes?
No. This is a text comparison: if a picture is swapped or a paragraph moves to another page with the same words, the text diff sees no change. For visual checks, open the two files side by side.
Which file is the 'original'?
The first file you select is treated as the original and the second as the revised version: lines only in the first are marked -, lines only in the second are marked +. Reorder the files before comparing to flip the direction.
What's in the report?
A plain-text (.txt) file: a summary of page counts, then for each page the differing lines with - and + markers, and a note for pages that don't align between the two files.