ToolBirch

Text Diff

Compare two texts by line or word with a colour-coded diff.Text Tools

Text Diff

Compare two texts line by line (or word by word) using a longest-common-subsequence diff. Everything is computed locally.

Paste text on both sides to see the differences.

About this tool

Check what actually changed between two versions of a paragraph, config or list without a terminal. The diff is a standard longest-common-subsequence comparison, so moves and edits are reported the way a programmer expects.

How to use the Text Diff tool

  1. Paste the original. Left side holds the before text.
  2. Paste the changed text. Right side holds the after text.
  3. Read the diff. Green rows are additions, red rows are deletions; unchanged rows provide context.

Supported formats

Input

  • Two plain-text inputs

Output

  • Colour-coded diff rows
  • Added and removed counts

Inputs are validated before anything is processed. Invalid values and unsupported files are rejected with a clear error instead of failing silently.

Frequently asked questions

Which algorithm is used?

A longest-common-subsequence diff over lines or whitespace-separated words — the same family of algorithm Git uses.

Is my text uploaded?

No. The comparison runs entirely in the browser tab.

Does it highlight character changes inside a line?

The line view shows whole rows; switch to word view for finer granularity inside paragraphs.

Why does a moved line show as removed and added?

LCS diffs do not track moves. A line that moved is reported as a deletion plus an addition.

Privacy

Everything you enter stays in this browser tab. There is no upload endpoint for tool inputs, no account, and no server-side copy of your text or files. Results are produced locally and disappear when you close the page.

No account is required and no file is ever uploaded. See the privacy policy for details about analytics and the limited data this site stores.

Known limitations

  • Very large documents are capped at 400 displayed rows for responsiveness.
  • Moved lines appear as separate removals and additions rather than move markers.
  • Word mode splits on whitespace, so punctuation attaches to the neighbouring word.

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