Diff Checker
Compare two versions of code, config or text side by side, with changed words highlighted and a unified diff you can copy.
Free · No upload · 100% on your device
How to use Diff Checker
- Paste the original text on the left, or open a file.
- Paste the changed text on the right.
- Choose the settings in the side panel. The comparison updates as you type.
- Copy or download the result.
Private by design. Everything you type, open or record is processed in this browser tab and is never uploaded to KittySuite.
About Diff Checker
Open two files or paste two snippets. Lines are aligned with the longest-common-subsequence method used by Git, and each changed line is compared word by word. Ignore spacing to skip indentation-only changes.
Everything runs in this browser tab: your text is never uploaded or stored, and the result updates as you type. It keeps working offline once the page has loaded.
Diff Checker: frequently asked questions
How do I compare two code files?
Open two files or paste two snippets. Changed lines are highlighted side by side, with changed words marked.
Can I ignore indentation changes?
Yes. Turn on “Ignore spacing” to skip whitespace-only changes. You can also ignore case.
Can I get a unified diff?
Yes. Copy or download the unified diff to paste into a review or patch.
Is my code sent anywhere?
No. Both versions are compared in this browser tab and never uploaded.