Text Diff Checker

Paste two texts and instantly see exactly what changed — added, removed, and modified lines highlighted side-by-side.

Ignore case Ignore leading/trailing whitespace Show unchanged lines Highlight changed characters

Original

Modified

Added

Removed

Changed

Unchanged

Enter text in both panels and click Compare

How to Use

Paste the original text into the left panel and the modified text into the right panel.
Choose options: ignore case, ignore whitespace, or show/hide unchanged lines.
Click Compare to generate the diff. Results appear in the panel below.
Green lines are additions, red lines are deletions, yellow lines are changes.
With "Highlight changed characters" enabled, the exact changed characters within a line are marked.

About This Tool

This diff checker uses the Myers diff algorithm — the same algorithm used by Git and most version-control systems — to compute the minimal edit distance between two texts. Results are displayed as a side-by-side comparison with colour-coded lines, line numbers, and optional character-level highlighting for changed lines. Everything runs in your browser: no text is ever uploaded to a server, making it safe for proprietary code, configuration files, legal documents, or any sensitive content.

Frequently Asked Questions

Is there a size limit on the texts I can compare?

There is no hard limit, but very large texts (hundreds of thousands of lines) may be slow because the diff is computed in the browser. For typical code files, configuration files, and documents the comparison is instantaneous.

How is this different from `git diff`?

The underlying algorithm is the same Myers diff, but this tool works on raw text you paste — it does not require a Git repository. It is ideal for quick comparisons of clipboard snippets, API responses, or any two blocks of text without setting up a file or running a terminal command.

Can I compare code files?

Yes. Simply open both files in a text editor, copy their contents, and paste them into the two panels. Syntax highlighting is not applied, but all line-level and character-level differences will be shown correctly.