UtilityBaseText Tools
Text Diff Checker
Compare two texts and see every added and removed line highlighted.
Updated July 7, 2026
How to use the text diff checker
- 1Paste the original text on the left and the changed version on the right.
- 2Enable 'ignore whitespace' if formatting differences don't matter.
- 3Click Compare and read the unified diff — green lines were added, red struck-through lines were removed.
- 4Check the +/− counts for a quick summary of how much changed.
Common uses
- Spotting exactly what changed between two versions of a document or contract
- Reviewing edits someone made to your writing
- Comparing configuration files or environment variables between systems
- Verifying a paste or migration didn't silently alter content
Frequently asked questions
How does the comparison work?
It computes the longest common subsequence of lines between the two texts, then marks everything outside that subsequence as added or removed. This keeps unchanged content aligned even when lines move.
Does it compare word-by-word within a line?
The comparison is line-based: a line with any change shows as a removal plus an addition. For prose where lines are long, breaking text into one sentence per line first gives much more granular results.
What does 'ignore whitespace' do?
It trims each line and collapses runs of spaces before comparing, so reindented code or re-spaced text registers as unchanged. Use it when formatting churn is hiding the real edits.
Is my text uploaded anywhere?
No. The diff runs entirely in your browser's memory — safe for contracts, unreleased copy, and anything else confidential.
About this tool
The text diff checker compares two blocks of text line by line and renders a unified view with additions highlighted in green and removals in red — the same visual language as code review tools, applied to any text. It uses a longest-common-subsequence algorithm, so unchanged lines stay aligned even when content shifts position. An ignore-whitespace option treats reindented or re-spaced lines as identical, cutting noise when formatting changed but content didn't. Compare contract revisions, before/after copy edits, configuration files, or two versions of anything — locally, with nothing uploaded.
Like everything on UtilityBase, the text diff checker runs entirely in your browser — nothing you enter is uploaded or stored on a server. It's free to use with no account required. Browse more text tools here.
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