Compare two PDF files — text and visual, in your browser
To compare two PDFs, drop both files into Diffesq: it shows every text change page by page — including paragraphs that merely moved — plus a visual lens that highlights layout and image differences, without uploading either file. The comparison is page-aware: pages are matched by content, so an inserted page never cascades false changes onto everything after it.
Because everything runs locally in your browser, it's suited to documents you can't send to a third-party service: contracts, filings, invoices, anything confidential.
How it works
- Open the Diffesq workbench and drop a PDF on each side.
- Diffesq extracts each page's text on your device and aligns pages by content.
- Review insertions, deletions, edits, and moved paragraphs anchored to their pages — or switch any page pair to the visual lens to see the rendered pages with differing regions highlighted.
- Export a report (HTML, Markdown, JSON, PDF) generated on your device.
What the comparison covers
- Page-aware text comparison with word-level highlighting; relocated paragraphs are reported as a single moved change — even across pages — never as an unrelated delete and insert.
- Added, removed, and reordered pages are reported as page-level changes.
- A per-page visual lens renders both pages from the PDFs and highlights the regions that differ — layout shifts, swapped images, stamps, signatures.
- Scanned or image-only PDFs degrade automatically to the visual comparison, clearly labeled — never a silent "no differences".
- Very large documents warn before comparing (never refused); comparisons show progress and can be cancelled. Password-protected PDFs aren't supported in this release.
Free vs Pro
Structured-file comparisons run in full on your device on the free tier, with about a third of the results shown as a preview; Pro unlocks the complete results and clean, unwatermarked exports (HTML, Markdown, JSON, PDF).
See Pricing for plans — $6/month, $48/year, or $119 once.
Privacy
Every comparison runs locally in your browser. Your files are never uploaded — there is no server that receives them, and the page keeps working with Wi-Fi turned off. Details in the Privacy Policy.
Frequently asked questions
Does it OCR scanned documents?
No — scanned pages compare visually, with differing regions highlighted. Text comparison needs an extractable text layer.
Are my PDFs uploaded anywhere?
No. Both files are parsed, rendered, and compared entirely on your device.
Does it work offline?
Yes — once the page has loaded, parsing, comparing, and rendering all happen on your device. Turn off Wi-Fi and it still works.
Do I need an account?
No. Comparisons run without any signup. Pro features unlock with a license key — still no account or login.