🔍 Line by Line · Color Coded · Free

Text Diff
Checker

Compare two texts and see every difference highlighted line by line. Added lines in green, removed in red, unchanged in grey.

Original text (A)
Modified text (B)
Auto-compare as you type Case insensitive Ignore leading/trailing spaces Ignore empty lines
Added in B
Removed from A
Unchanged
Paste text in both fields to see differences…

Free Online Text Diff Checker — Compare Two Documents

ExperToolBox's text diff tool compares two versions of a text and highlights every difference line by line. Added lines (present in B but not A) are shown in green. Removed lines (present in A but not in B) are shown in red. Unchanged lines are shown in grey. The format mirrors the classic Unix diff output used by version control systems like Git.

Optional settings let you ignore case differences, trim leading and trailing whitespace before comparison, and skip empty lines — useful when you want to focus on meaningful content changes.

Common uses for text diff

Text diff tools are used in software development to review code changes before committing to Git. Writers use them to compare drafts and track revisions. Lawyers and editors use them to compare contract versions. Data analysts use them to spot changes between exported reports. Teachers use them to compare student submissions against originals for plagiarism detection.

How the diff algorithm works

This tool uses a line-by-line comparison algorithm. For each line position, it checks whether the line in A matches the line in B. If they match, it's unchanged. If B has a line where A doesn't (or vice versa), it's added or removed. For a more sophisticated diff that detects moved blocks and minimal edit distances, the Myers diff algorithm (used by Git) is more accurate — this tool uses a simpler approach optimised for speed and browser performance.

Frequently Asked Questions

Can I compare code files?
Yes. Paste any text including code, and the diff will work line by line. For syntax highlighting in the diff output, use a dedicated code diff tool. This tool is best for prose text, data files, and simple code comparisons.
Is there a size limit?
No hard limit. The tool processes text in your browser. For very large texts (thousands of lines), the comparison may take a moment but there's no restriction.
What does "case insensitive" do?
With case insensitive enabled, "Hello" and "hello" are treated as identical lines and shown as unchanged. Without it, any difference in capitalisation, even a single character, is treated as a changed line.

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