Diff Checker

Compare two text blocks side-by-side with color-coded line-by-line differences; apply or generate unified diff patches; load files via drag-and-drop; word-level and JSON-aware modes.

Ln: 1  Col: 1 13px
Ln: 1  Col: 1 13px

Diff updates automatically · Press Ctrl+Enter to force refresh

Enter or load text in both panels to compare.

Diff Checker

Compare two text blocks side-by-side with color-coded line-by-line differences; apply or generate unified diff patches; load files via drag-and-drop; word-level and JSON-aware modes.

Common uses

  • Compare two versions of a config file
  • Apply a unified diff patch to text
  • Find word-level changes between two paragraphs

Frequently asked questions

How do I compare two texts?

Paste the original on the left and the changed version on the right; differences are highlighted line by line. You can optionally ignore whitespace.

Is my data uploaded to a server?

No. This tool runs entirely in your browser — your input is processed locally on your device and is never uploaded or stored on a server.