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EVOA Toolbox

Text Diff Checker

Compare two texts side by side and see added and removed lines, words or characters. Copy the result as a unified patch.

Processed locally in your browser. Your text is not uploaded.

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What this tool does

Paste an original and a modified version and the tool highlights exactly what changed. Compare by lines (like git diff), by words (best for prose, contracts and copy edits) or by individual characters (best for spotting a single typo in a long identifier). Additions are marked with + and underlined, removals with − and struck through, so the result is readable even without colour.

On a wide screen you get a side-by-side view with line numbers on both sides; on a phone the same changes are shown as a single unified list. Long unchanged stretches fold away so you only see changes with three lines of context, and you can expand any fold. Options ignore whitespace differences or letter case, which is useful when reformatting or re-capitalising produced noise.

The comparison uses the jsdiff library. Statistics show how many lines, words or characters were added, removed and unchanged, plus a similarity percentage. You can copy or download the changes as a standard unified patch for code review, tickets or the patch command. Large inputs are diffed in a background thread so the page stays responsive.

How to use it

  1. 1Paste the original text on the left and the changed text on the right (or press Example).
  2. 2Choose Lines, Words or Characters, and optionally ignore whitespace or case.
  3. 3Review the highlighted changes and the statistics. Switch between side-by-side and unified view if you like.
  4. 4Copy the unified patch or download it as a .patch file.

Supported formats

Plain text in any language. The patch output uses the unified diff format understood by git, patch and most review tools.

Privacy

This tool runs in your browser. The data you provide is processed on your device and is not sent to our servers.

Limitations

  • Inputs over about 1 MB combined ask for confirmation first; very large or very different texts can take a long time and may be stopped as too complex.
  • The diff is computed on text only. Binary files, formatting and images are not compared.
  • Moved blocks are shown as a removal plus an addition; the algorithm does not detect moves.
  • The unified patch always records real differences, so the ignore-case option is not applied to it.
  • Only the first 3,000 rows are drawn at once to keep the page fast; expand folds selectively on huge diffs.

FAQ

What is the difference between lines, words and characters mode?

Lines mode marks whole lines as changed, like git diff. Words mode highlights only the changed words inside a sentence. Characters mode pinpoints single-letter edits. The statistics use the same unit.

Can I use the result with git or patch?

Yes. The copied text is a unified diff with 'original' and 'modified' as file names and three lines of context. Rename the headers if your tool expects real paths.

Why does ignoring whitespace help?

Re-indenting or re-wrapping text changes many lines without changing meaning. With the option on, lines that differ only in spaces or tabs count as unchanged.

Is my text uploaded anywhere?

No. The comparison runs in your browser, in a background worker for large inputs.

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