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Text Diff Comparator

Paste two versions of any text and see exactly what changed. Uses an LCS-based line diff algorithm to find the longest common subsequence and mark every other line as added or removed. Up to 5,000 lines per side are supported.

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How it works

We split each input by line and build a Longest Common Subsequence DP table, then backtrack to produce the diff. Each line is tagged unchanged, added or removed and shown with old/new line numbers. Output is also available as a unified +/- block for copy or download.

How to use it

  1. Paste both versions

    Drop the old version into the left pane, the new version into the right. Up to 5,000 lines per side are supported.

  2. Run the diff

    An LCS-based algorithm finds the longest common subsequence between the two inputs, then tags every other line as added or removed.

  3. Inspect added and removed

    Lines come back with a +/- marker and old/new line numbers. Unchanged lines are kept as context so the diff reads like a patch.

  4. Copy or download the diff

    Take the unified +/- block into a code review, a spec change log, a translation audit, or an email summarising what changed.

Use cases

Compare two drafts of a document and spot the edits.

See what changed between two versions of a config file.

Review a colleague's edits without firing up git.

Audit a translation against the original.

Diff two log files quickly.

Your data never leaves your browser

Every utility runs entirely on your device. Nothing is uploaded, nothing is stored on a server. You can disconnect from the internet and they keep working.

Frequently asked questions

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