How does the PDF comparison work?

Both PDFs are rendered and analyzed entirely in your browser. For each page you get three views: the two pages side by side, a visual difference heatmap that highlights changed pixels in red, and a word-level text diff that lists exactly which words were added or removed.

Are the files uploaded anywhere?

No. Rendering (PDF.js) and diffing run locally in your browser — neither PDF leaves your device, so it's safe for confidential contracts and drafts.

Can it compare documents with different page counts?

Yes. Pages are compared by position; if one file has more pages, the extra pages are shown as present on one side only. The text diff still runs on whichever pages exist.

What kinds of changes can it detect?

The visual heatmap catches any change to the rendered page — text edits, moved images, formatting, colors. The text diff specifically reports added and removed words, which is ideal for reviewing wording changes between versions.

Compare PDFs — Visual & Text Difference, Free & Private

Compare two PDF files in your browser: side-by-side pages, a visual difference heatmap, and a word-level text diff showing exactly what was added or removed. No uploads.