Code Diff Tool
Compare two blocks of text or code side by side. See additions, deletions, and unchanged lines.
How to Compare Code Online
Paste the original text or code in the left panel and the modified version in the right panel, then click Compare. The tool computes a line-by-line diff and highlights additions in green and deletions in red. Toggle between unified view (interleaved changes, like git diff) and side-by-side view for a visual comparison. Line numbers help you navigate to specific changes quickly. The summary shows how many lines were added, removed, and left unchanged, giving you a quick overview of the change scope.
When to Use a Diff Tool
Diff comparison is fundamental to code review, debugging, and documentation. Use it to verify configuration changes before deployment, compare API response versions, check database migration scripts, or review text edits in documents. Unlike git diff, this tool does not require a repository — just paste any two text blocks and compare them instantly. The diffing algorithm runs entirely in your browser using a longest-common-subsequence approach, so your code and data never leave your device.