Compare PDF
Compare PDF lets you check two versions of a document and pinpoint exactly which lines of text, numbers, tables or images were added, removed or edited. The tool renders every page of both files and compares them at the pixel level, so it catches even changes in PDFs that keep the original hidden text layer (text that was redacted or overwritten). Results show both pages side by side with changed regions outlined, a detailed change report and an overlay preview mode. Everything runs right in your browser — your files never leave your device.
When do you need it?
- Review a revised contract against the original before signing.
- Check printed or submitted forms for changed content, figures or signatures.
- Compare drafts of reports, theses and technical documents across revisions.
- Reconcile invoices, vouchers and minutes between scanned and digital copies.
- Verify a translation does not distort the original content.
Key features
- Pixel-accurate page comparison — catches redacted or overwritten text too.
- Two view modes: side-by-side pages with change boxes, or a content overlay.
- Before → after change report with page numbers, keyword filter and HTML download.
- Zoom, page navigation and synchronized scrolling for easy inspection.
- Runs 100% in the browser, free with no page limits.
How to use
- Upload or drag & drop your file — everything runs right in your browser.
- Pick your options and hit the process button.
- Download the result — fast, free, no account required.
Safety & privacy
Both PDFs are opened and rendered entirely in your browser with pdf.js — never uploaded, stored or shared. Document content, including sensitive contract or record data, never leaves your device.
Genuinely free — no limits
KitsyApp is 100% free — no signup, no daily limits, no watermarks. Processing quality is on par with paid tools like Smallpdf or iLovePDF, and your files are processed on your own device instead of someone else's server.
Frequently asked questions
Can Compare PDF detect redacted or blacked-out text?
Yes. Many redaction tools just draw a black rectangle over text that stays in the file. Because we compare the rendered pixels, that region is correctly flagged as a change.
Can files with different page counts be compared?
Yes. Pages are compared one by one in order; pages that exist in only one file are reported as present in file A or file B only.
Can scanned PDFs be compared?
Yes. Comparison is based on the rendered image of each page, so scans are handled normally. For scans with slight misalignment, differences usually appear along the margins.
Can I save the comparison result?
Yes. You can download the change report as an HTML file (opens in any browser, printable) right from the results page.