Is the diff line-by-line or character-by-character?

The default view is line-by-line, which is the most readable for code and prose. Within changed lines, character-level differences are also highlighted.

Can I compare code files?

Yes. Paste the content of any two text files — code, config files, markdown, JSON — and the diff will show all differences. Syntax is not interpreted; it treats all input as plain text.

What do the colours mean?

Green highlighted lines are additions (present in the second text but not the first). Red highlighted lines are deletions (present in the first text but removed in the second). Unchanged lines are shown without highlighting.

Can I share the diff with someone?

Use the Share button to generate a URL that encodes both text inputs, allowing you to share the exact comparison with a colleague.

What diff algorithm does this use?

The tool uses the Myers diff algorithm, which is the standard algorithm used by Git for showing the minimum number of insertions and deletions between two texts.

Can I ignore whitespace when diffing?

Yes. Enable "Ignore whitespace" to treat lines that differ only in leading/trailing spaces or indentation as identical — useful when comparing code that has been reformatted.

Diff Checker

The Diff Checker compares two blocks of text line-by-line and displays the additions, deletions, and unchanged lines with colour highlighting — green for added lines, red for removed lines. Useful for comparing code versions, document revisions, configuration file changes, or any two text samples you need to diff without a code editor.

Runs entirely in your browser — your input is never uploaded, stored, or logged.

Paste two versions of any text and instantly see what changed, what was added, and what was removed. For bulk replacements in a single text, try the Find & Replace tool.

How to Use

1Paste the original text in the left panel.
2Paste the modified text in the right panel.
3Differences are highlighted: additions in green, removals in red.
4Scroll through the diff to review all changes.

Common Uses

→Compare two versions of a document to find what changed
→Review code changes without a diff tool installed
→Check what changed between two CSV or JSON exports
→Compare API responses side by side

Examples

Code change

Input

Original:
const x = 1;
const y = 2;

Output

Modified:
const x = 1;
const z = 3;

Frequently Asked Questions

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