Does it compare word by word or line by line?

It compares line by line, which is the clearest way to review edits in paragraphs, lists and code. Lines that differ are shown as a removal plus an addition.

Yes. It works with any plain text, including source code, JSON, CSV and config files. Indentation and spacing differences are detected.

Is my text uploaded anywhere?

No. The comparison runs locally in your browser — neither block of text is sent to a server.

Text Diff Checker

Compare two blocks of text or code and highlight added, removed and unchanged lines side by side.

Changed Text

What Is the Text Diff Checker?

The Text Diff Checker compares two versions of text or code and highlights exactly what changed — added lines in green, removed lines in red and unchanged lines in gray. It uses a line-by-line longest-common-subsequence comparison, the same approach as developer diff tools, and runs entirely in your browser so private content stays on your device.

How It Works

Paste your original text on the left and the changed text on the right. The differences appear automatically below, with counts of added and removed lines. Scroll the result to review every change in context.

When to Use It

Use it to compare document drafts, spot edits between two versions, review configuration or code changes, check what a tool or AI rewrote, or verify that two files are identical.

Frequently Asked Questions

Does it compare word by word or line by line?: It compares line by line, which is the clearest way to review edits in paragraphs, lists and code. Lines that differ are shown as a removal plus an addition.
Can I compare code?: Yes. It works with any plain text, including source code, JSON, CSV and config files. Indentation and spacing differences are detected.
Is my text uploaded anywhere?: No. The comparison runs locally in your browser — neither block of text is sent to a server.

Last reviewed: 2026-06-27