Is my text uploaded anywhere when I compare it?

No. The comparison runs entirely in your browser using JavaScript. Neither the original nor the changed text ever leaves your device, so your data stays completely private.

What's the difference between side-by-side and unified view?

Side-by-side view shows the original and changed text in two parallel columns, making it easy to scan line-by-line. Unified view stacks the changes in a single column with added and removed lines interleaved, similar to a Git diff.

What does 'ignore whitespace' do?

When enabled, lines that differ only by leading, trailing, or repeated spaces and tabs are treated as identical. This is helpful when indentation or formatting changed but the actual content did not.

How is the diff calculated?

The tool uses a line-based longest common subsequence (LCS) algorithm to find the smallest set of additions and removals that turn the original text into the changed text — the same core approach used by tools like Git and diff.

Can I compare code, JSON, or logs?

Yes. The diff checker is line-based and content-agnostic, so it works well for source code, configuration files, JSON, CSV, logs, or any plain text you paste in.

Diff Checker

Compare two texts and instantly highlight added and removed lines — privately in your browser.

Original

Changed

Ignore whitespaceIgnore case

Paste text into both boxes to see the differences here.

How it Works

Spot every change between two texts in three simple steps.

Paste the original

Add the first version of your text or code into the Original box.

Paste the changed version

Add the updated version into the Changed box to compare against.

Review the highlights

Added lines appear in green and removed lines in red, in split or unified view.

Diff Tips

Get cleaner comparisons with these tips.

Ignore whitespace for reformats

If only indentation or spacing changed, enable Ignore whitespace so the diff focuses on real content changes.

Use unified view for reviews

Unified view mirrors the Git diff format many developers already read in pull requests and commit history.

Split view for translations

Side-by-side view is ideal when comparing two full documents, drafts, or translations line by line.

Ignore case for prose

When capitalization is not meaningful, enable Ignore case to avoid flagging purely cosmetic differences.