Free Online Diff Checker
Great before sending a document back to a colleague: it shows exactly which sentences moved.
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How to use Diff Checker
- Paste the original on the left and the changed version on the right.
- Ignore case or whitespace if formatting noise bothers you.
- Read the coloured diff.
- Copy only the changed lines if you need them.
Questions about Diff Checker
How large can the files be?
A few thousand lines is comfortable; beyond that the browser is better served by a dedicated diff tool.
Does it do word-level changes?
Yes, when a line differs the tool falls back to word comparison inside that line.
About Diff Checker
Compare two texts and highlight the differences with our free online Diff Checker. 100% browser-based, fast, and private—no login or file uploads required.
These text and code tools clean and transform strings: count words, convert case, deduplicate lines, encode or decode Base64 and URLs, escape entities, hash, format JSON and compare two versions.
This tool runs in your browser. The file is not uploaded. Everything runs on the text you paste, so you can safely process snippets of code or logs; nothing is sent anywhere, and clearing the box removes it from memory.