About Text Diff

Compare two text blocks and highlight differences. Part of the DevTools Surf developer suite. Browse more tools in the Text / String collection.

Use Cases

• Comparing configuration files before and after deployment
• Spotting differences between staging and production API responses
• Reviewing translated content against the original source text
• Auditing changes in legal documents or policy updates

Tips

• Compare config file versions to spot unintended changes
• Paste two API responses side by side to find differences
• Use the highlighted output to document changes in code reviews

Fun Facts

• The diff algorithm was published by Hunt and McIlroy in 1976 at Bell Labs and became the foundation for all modern diff tools.
• Git uses the Myers diff algorithm by default, published by Eugene Myers in 1986, which finds the shortest edit script.
• The first version control system, SCCS, was created by Marc Rochkind at Bell Labs in 1972 and relied heavily on diff.

FAQ

Line diff or character diff?

Both — line-level by default, word-level highlighting within changed lines. Switch to character-level for very short texts where line-level isn't granular enough.

Does it handle CRLF vs LF?

Configurable — ignore line-ending differences, or highlight them as changes. Default is ignore (since they're often artifacts of editor mixing).

Can I diff very large files?

Up to ~5 MB comfortably. Beyond that use `diff` at the command line — browser memory and CPU become bottlenecks.

Is there an ignore-whitespace mode?

Yes. Matches `diff -w` behavior — whitespace changes (added/removed spaces, tabs) are suppressed. Great for reviewing reformatted code.