Diff Checker

Comparing two versions of text—code, config, or prose—reveals what changed. Manually scanning side by side is slow and error-prone. A diff highlights additions and deletions so you see exactly what changed. This Diff Checker pastes two text blocks side by side and shows the differences. Additions in one color, deletions in another. Useful for code reviews, document edits, and spotting unintended changes. No diff tool to install—it runs in your browser.

Paste the original in the first box and the modified version in the second. The tool computes a line-based diff and highlights added and removed lines. For code, that often corresponds to logical changes. For prose, it shows edited sentences or paragraphs. Use it to compare config files before and after a change, drafts of an article, or two versions of a script. See what landed in the update, what was removed, and what stayed the same.

Code reviewers use it to verify patches. Paste the before and after; the diff shows the impact. For larger files, a dedicated diff tool (e.g. Git) may be better, but for quick checks and ad-hoc comparisons, this works. Writers use it to compare revisions. Support teams use it to see what changed between versions of a document or template. The tool doesn't understand semantics—it compares text. For structured data like JSON, formatting differences can dominate; normalize first if needed.

All processing is client-side. Your text never leaves your device. Paste sensitive code, proprietary docs, or personal writing. No storage, no logs. Free and instant. Bookmark it for the next time you need to compare two pieces of text.