Text Diff Checker
Paste an original text and a revised version to see exactly which lines changed — additions in green, deletions in red, all computed locally.
How to use the Text Diff Checker
Paste the original text on the left and the modified version on the right.
Click Compare texts — changed lines appear with − for removed and + for added.
Review the counts of added, removed and unchanged lines above the output.
Frequently asked questions
How does the comparison work?
The tool runs a line-by-line LCS (longest common subsequence) diff — the same class of algorithm used by Git — to match unchanged lines and highlight real changes.
Can I compare code?
Yes — it works well for source code, config files, JSON and any line-based text. For very large files, a dedicated code-diff tool may be faster.
Is my text uploaded?
No — the comparison runs entirely in your browser, so confidential drafts and code stay on your device.