Text Diff Checker
Paste two versions of a text or code file and see additions and removals highlighted line by line. Comparison runs locally, so it's safe for private code and documents.
Runs locally — nothing you enter is sent
Developer
Free · no signup
How to use
- Paste the original text into the left panel.
- Paste the changed text into the right panel.
- Run the comparison and review highlighted additions and deletions line by line.
Supported formats
- Any plain text: source code, configuration files, prose, JSON, logs.
Privacy
This tool runs entirely in your browser. Nothing you enter or open is sent anywhere. Privacy policy.
Limitations
- Comparison is line-oriented; moved blocks show as a deletion plus an addition.
- Extremely large inputs (hundreds of thousands of lines) may be slow, since the diff runs in the page.
FAQ
Is this diff tool private?
Yes. Both texts are compared in your browser with no network calls, so proprietary code never leaves your machine.
Does it show character-level differences?
Differences are highlighted per line. Within-line (character-level) highlighting is deliberately kept simple to stay fast on large inputs.