Free Developer Tool - runs 100% in your browser
Text Diff Checker
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Compare two texts online and spot every change
This text diff checker compares two blocks of text line by line and highlights what wasadded and what was removed - the same unified-diff view you know from Git, generated instantly in your browser. Use it to compare code snippets, config files, contracts, SQL dumps, translations or two versions of an article.
How the diff is computed
The tool uses the longest common subsequence (LCS) algorithm - the classic approach behindgit diff and diff -u. It finds the largest set of lines the two texts share in order, then reports everything outside that set as an insertion or deletion. That gives minimal, readable diffs rather than naive position-by-position comparison, which flags every subsequent line after a single insertion.
When a diff tool saves the day
- Code review without a repo - compare a snippet from chat with what's actually deployed.
- Config drift - spot the one changed line between staging and production configs.
- Document versions - see edits between contract or policy revisions.
- Data debugging - find the record that differs between two exports.
Both texts stay on your device - nothing is uploaded, so it's safe for proprietary code and confidential documents. Also useful alongside the JSON formatter: format both payloads first, then diff them to see exactly which fields changed.