Support: Diff Checker

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Common questions

How do I compare two texts for differences?

Paste the original in the left box and the new version in the right and press Compare. Lines that were removed are red, added lines green, and inside an edited line the changed words are highlighted.

Can I compare two files?

Yes. Press Open a file above each box to load a text file, such as .txt, .csv, .json, .html or source code, up to 10 MB. Word and PDF files are not text; extract their text first.

What does Ignore spaces and tabs do?

Runs of spaces and tabs are treated as one space and leading and trailing ones are dropped before comparing, so re-indented code or reflowed text shows only the real changes. Ignore case treats A and a as the same; Ignore blank lines drops added or removed empty lines.

What is a unified diff?

The standard text format for changes, used by patch tools and code reviews: a header for each changed region, lines starting with a minus for removed, plus for added, and three unchanged lines of context around them. Copy unified diff puts it on your clipboard.

Why are some unchanged lines hidden?

Long runs of identical lines are folded to keep the result readable, with a note of how many. Click the note to show them all.

Does it work for code?

Yes. Code is compared like any text, with indentation shown as typed; tick Ignore spaces and tabs to ignore re-indentation. Nothing is syntax-aware, so a moved function shows as removed and added.

Is my text sent anywhere?

No. The comparison runs in your browser on your own device and nothing is stored.

Is it free?

Yes, completely free, with no sign-up.