Developer

Text diff checker

Compare two blocks of text and highlight additions, deletions, and unchanged lines side by side.

Original text

Modified text

Diff output

100% private. All processing happens locally in your browser — no files or data are ever sent to a server.

How to use Text diff checker

01 Paste or type your input into the text field provided
02 The output generates instantly as you type
03 Click Copy to send the result straight to your clipboard

Frequently asked questions

Common questions about Text diff checker.

Is Text diff checker free to use?

Yes, Text diff checker is completely free. No account, subscription, or payment is ever required — just open the page and start using it.

Does Text diff checker upload my data to a server?

No. Text diff checker runs entirely in your web browser using client-side JavaScript. Your files, text, and data never leave your device, making it 100% private.

Can I use Text diff checker on my phone or tablet?

Yes. Text diff checker is fully responsive and works on all modern smartphones, tablets, and desktop browsers without installing any app.

Does Text diff checker work without an internet connection?

Yes. Once the page has loaded, Text diff checker works fully offline — all processing is done locally in your browser.

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About Text diff checker

The Text Diff Checker compares two blocks of text and highlights the differences: additions in green, deletions in red, and unchanged lines in neutral. It uses a Longest Common Subsequence (LCS) algorithm for accurate line-by-line comparison — the same approach used by version control systems like Git. Common uses include reviewing changes between two versions of a document, comparing API responses during debugging, verifying that an edited passage matches its source, and spotting unintended changes in configuration files.