Text Diff Checker

Compare two blocks of text line by line and highlight what changed. Runs locally.

Paste two blocks of text and see exactly which lines were added, removed, or changed, highlighted side by side. Useful for comparing two drafts of an article, checking what changed between two versions of a config file, or reviewing edits to a legal document without a full version-control setup. Comparison runs entirely client-side, so neither block of text leaves your browser.

Runs in your browser // nothing is uploaded

Loading tool

Details

Runs
In your browser
Files uploaded
No
Cost per run
Free
Sign-in
Not required
Works offline
Yes, once loaded

Last updated 2026-08-03

Common questions

Does it compare word by word or line by line?

The comparison works line by line, highlighting added, removed, and changed lines between the two inputs.

Can I compare code, not just prose?

Yes - it works on any plain text, including source code, configs, or JSON.

Is my text uploaded anywhere?

No - the comparison runs entirely in your browser.

Does it highlight character-level changes within a line?

Changed lines are shown together so you can visually spot the difference; the highlighting operates at the line level.

Related tools