Diff Checker Online

Diff Checker Online for Text, Code, and JSON

This diff checker online compares two text values side by side and highlights what was added, removed, or changed. It is useful for source code, configuration, documentation, logs, and API responses.

Comparison happens in your browser. The text in either editor is not uploaded to an application server.

How to Compare Two Texts

1. Paste the earlier or expected version into Original.
2. Paste the newer or actual version into Modified.
3. Review the highlighted differences as you edit either pane.
4. Copy either version when needed, or select Clear to reset the comparison.

The left pane represents removals from the original, and the right pane represents additions in the modified version. Unchanged sections remain aligned to provide context.

Compare JSON Without Key-Order Noise

Two JSON objects can contain the same values while listing their keys in a different order. Select Sort JSON Keys to parse both panes, recursively sort object keys, and rewrite them with consistent indentation before comparing.

Both panes must contain valid JSON. Arrays retain their existing item order because changing array order can change the meaning of the data. If either pane is invalid, the tool reports which side needs attention and leaves both values unchanged.

For syntax errors or an expandable tree view, use the JSON formatter and validator first.

Common Diff Checker Uses

• Review code or configuration changes before committing them.
• Compare expected and actual API responses.
• Inspect edits between two document drafts.
• Find environment differences in configuration files.
• Compare logs after normalizing timestamps and request identifiers.
• Check generated HTML against an earlier version.

Reading a Side-by-Side Diff

Changed lines are paired where possible so you can inspect smaller character-level edits within them. Added lines appear only on the modified side, while removed lines appear only on the original side. Unchanged sections remain aligned to provide context.

The checker compares text, not the semantic meaning of a programming language. Formatting changes, line endings, and whitespace can therefore appear as real differences.

Related Developer Tools

• Format and validate JSON before comparing payloads.
• Beautify HTML to reduce indentation-only changes.
• Convert UTC offsets when comparing timestamped logs.