Compare two PDFs
Show what changed between two versions of a document, word by word.
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What this does
This shows what changed between two versions of a document, word by word: what was added, what was removed, and — if you ask — which parts of the page look different even though the words are the same. It compares page one with page one and so on, which means a page inserted at the front makes everything after it look changed, because to a reader it is.
What it will not do
Every tool here says what it cannot do, in its own words, before you rely on it.
- The pages are compared in order: page one with page one. A page inserted at the front makes every page after it look changed, because to a reader it is.
- A word is compared as it reads, not as it is drawn. A change of font, colour or position that leaves the words alone is a visual difference, and is reported as one.
- Comparing how the pages look needs a browser that can draw a page off-screen. In one that cannot, turn that comparison off and the words are still compared.
- A scanned page holds no words to compare. Two scans are compared by how they look and nothing else.
Questions people ask
Why is every page after page three marked as changed?
Because a page was inserted or removed, and the pages after it no longer line up. That is what a reader sees too. Compare the two versions of a section rather than the whole document if you need to isolate the rest.
Can it compare two scans?
Only by how they look — there are no words in a scan to compare. Run Make a scan searchable over both first if you want a word-by-word comparison.
Is my file uploaded anywhere?
No. The work happens in this browser tab, on your own machine. There is no server in this product to send a file to, which is why the promise is checkable rather than something you have to take on trust: open your browser's network panel and watch it do the work without making a request.
Is there a size limit, or a limit on how many files?
None that we impose. The limit is your own machine's memory, because that is where the work happens — a few hundred megabytes is comfortable on a laptop, and less on a phone. There is no daily task counter, no queue and no account.
What does it cost, and what is the catch?
Nothing, and there is no paid tier that unlocks features: the whole product is the free one. That is affordable because running it costs us nothing — your computer does the work — so there is no per-file cost to recover, no advertising and no data to sell.