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COMPARE PDFS
Compare PDFs Online Free
See what changed between two PDFs — text lines and looks, page by page.
100% private — processed in your browser
Your files are processed locally in your browser with JavaScript. They are never uploaded to a server. You can verify this yourself: open your browser DevTools, go to the Network tab, and watch — no file data leaves your device.
How to compare two PDFs
Two versions of the same document, and nobody remembers what changed. This tool compares them page by page: first the text, line by line, then the look of each page. The first file you add is document A, the second is document B, and pages are compared in order — page 1 with page 1, and so on.
Drop both PDFs and press Compare PDFs. For each page you get the text changes (lines added and lines removed) and a visual difference in percent: how much of the rendered page actually changed. A summary table shows every page at a glance, and the diff report downloads as a .txt file with the changed lines.
Two honest limits. First, the text diff is line-based: a moved paragraph shows as removed in one place and added in another, even though the words are the same. Second, the visual diff counts any pixel change, so a different font or a shifted margin looks like a big change even when the words match. Read the two numbers together: text tells you what the words did, visual tells you what the eye sees.
Everything runs in your browser, so both documents never leave your device. There is no daily limit.
How to use this tool
- 1Drop two PDFs: first document A, then document B.
- 2Press Compare PDFs.
- 3Read the per-page table, then download the diff report if you need the details.
Frequently asked questions
Which file is A and which is B?
The first file you add is document A and the second is document B. Added lines are lines only in B; removed lines are lines only in A. You can reorder the files with the up and down arrows.
Why does a moved paragraph show as changed?
The text diff compares lines in order, so a paragraph moved to another place counts as removed where it was and added where it went — even though the words are identical. The content did not change, only its position.
What does the visual percent mean?
How much of the rendered page differs in pixels: 0% means the pages look identical, 100% means nothing matches. Any pixel change counts, so a different font or a shifted layout pushes the number up even when the words are the same.
My PDFs are scans. Does the text diff work?
No — scanned pages have no text layer, so there are no lines to compare. The visual diff still works: it compares how the pages look. Reading text from a scan needs OCR.
Are my files uploaded anywhere?
No. Comparison happens entirely in your browser. Both PDFs never leave your device.