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Text & String

Text Diff Checker

Compare two text blocks and see exactly what changed. Line-level and word-level diff highlighting with added, removed, and changed lines clearly marked.

Free Client-Side No Sign-Up Nothing Stored
Paste two texts to compare
Original (Text A)
Modified (Text B)
ORIGINAL
MODIFIED

What This Tool Does

The Text Diff Checker uses a Longest Common Subsequence (LCS) algorithm to compare two text blocks line by line. Removed lines are highlighted in red on the left, added lines in green on the right. Options for case-insensitive comparison and whitespace ignoring help filter noise from the results.

Frequently Asked Questions

What is the difference between this and the Diff Checker tool?
This Text Diff Checker is optimised for plain text comparison — prose, lists, configuration values. The Diff Checker tool in the Regex & Testing category is designed for code, with a code-style monospace layout and line numbers.
How does word-level highlighting work?
For lines that were modified (not entirely added or removed), the tool highlights the specific words that changed within each line, giving you finer-grained insight into exactly what was altered.
Is my text sent to a server?
No. The diff is computed entirely in your browser using JavaScript. Nothing is transmitted anywhere.

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