How to Use the Text Diff Checker
Paste or load two versions of any text — code, JSON, YAML, logs, or prose. The tool uses a proper longest-common-subsequence (LCS) diff so insertions and deletions align correctly (not just line-by-line index comparison). Changed lines get word-level highlights when enabled.
- Side by side — original on the left, modified on the right, with line numbers.
- Unified — classic patch view with
+and-prefixes. - Export — copy or download a unified diff patch for reviews or git-style sharing.
Frequently Asked Questions
Is my text sent to a server?
No. Comparison runs entirely in your browser. Your data never leaves your device.
How is this different from a basic line compare?
Basic tools compare line 1 to line 1, line 2 to line 2, etc. This tool finds the best alignment so adding a line at the top does not mark every following line as changed.
Can I ignore formatting differences?
Yes. Enable ignore whitespace, ignore case, or ignore blank lines to focus on meaningful content changes.