Diff Checker Online
Use this free online Diff Checker tool to compare and view differences between two text outputs client-side.
How it works & FAQ
Why this is secure?
Text comparison runs entirely in your browser. Your text is never uploaded or seen by any server.
Step-by-Step Guide
- 1Paste the original text in the left panel and the modified text in the right panel.
- 2Additions are highlighted in green, deletions in red, and changed lines are shown side by side.
- 3Use the controls to switch between unified and split diff views.
Frequently Asked Questions (FAQ)
Can I compare files, not just text?
Paste the text content of any file — source code, config files, JSON, Markdown — and the diff runs instantly.
Does this do character-level or line-level diffing?
Line-level diffing is used by default, with character-level highlights within changed lines for precise change detection.
Can I compare two versions of code?
Yes — it works well for source code, configuration files, and any plain text. Syntax highlighting is applied when the language is detected.
Both text blocks are compared locally in your browser. No text is uploaded anywhere.