Compare PDFs (Visual & Text Diff)
Compare two PDF versions side by side — a visual pixel diff of what changed on each page, a line-by-line text diff, and which pages differ. Free, no upload.
Drop the original PDF or click to browse
Drop the revised PDF or click to browse
🔒 Both PDFs are rendered and compared entirely in your browser — nothing is uploaded.
See exactly what changed between two PDFs
Drop in an original and a revised PDF and this tool matches the pages up by what is on them rather than by their number, so a page inserted or deleted in the middle is reported as inserted or deleted instead of knocking every page after it into "changed". A matched pair is labelled with both of its page numbers, so you can see at a glance that page 4 of the original is page 5 of the revised. Every page of both files is rendered to an image at a common scale and compared pixel by pixel, so the areas that changed are highlighted in red — a moved paragraph, an edited figure, a new stamp or a tweaked number all stand out at a glance. Alongside the visual diff it extracts the text of each page and shows a line-level comparison that marks added and removed lines, plus a summary of how many pages differ. When the two files have a different number of pages, the extra pages are flagged as added or removed. You can switch between a side-by-side view and a diff overlay, and toggle the text comparison on or off. Above the pages sits a change report: every added and removed line of the whole comparison in one list, with a count, a search box, and Previous/Next buttons that scroll straight to the page a change is on — so a single altered figure is one search away instead of forty page cards down. And if the two files went into the wrong boxes, Swap exchanges them and runs the comparison again the other way round instead of making you start over.
Private by design
Both PDFs are opened, rendered and compared entirely in your browser with pdf.js — nothing is uploaded to a server, so it is safe for contracts, drafts and confidential documents, and it keeps working offline once loaded. A few limits are worth knowing: the visual diff compares rendered pages aligned from the top-left corner, so a change in page size or margins can register as a difference; scanned or image-only pages have no selectable text, so only the visual diff applies to them, and because there is no text to match them on they are lined up in page order instead — an inserted scan can push the rest out of step, and the tool says so on screen when that risk exists; and very large documents take longer and use more memory because every page is rasterized.
Frequently asked questions
How does the visual comparison work?
Every page of both PDFs is rendered to an image at the same scale and compared pixel by pixel. Any pixel whose color differs by more than a small threshold is marked, and those regions are painted red in the diff overlay so you can see precisely what moved or changed. A page is reported as changed once more than a tiny fraction of its pixels differ, or whenever its text differs at all — so a single edited number still shows up even though it moves almost no pixels.
Does it compare the actual text too?
Yes. The text of each page is extracted and compared line by line, with added and removed lines marked separately, so you get both a visual and a textual view of the changes. Scanned or image-only pages have no extractable text, so only the visual diff is shown for those.
Are my PDFs uploaded anywhere?
No. Both files are rendered and compared entirely in your browser with pdf.js, so they never leave your device and nothing is sent to a server. That makes the tool safe for sensitive documents, and it works offline after the first load.