Compare two texts side-by-side. Additions, deletions, and changes highlighted instantly. Everything runs locally in your browser.
Original and modified text displayed in two panes so you can instantly spot what changed. Scroll is synced between both sides.
Additions highlighted in green, deletions in red. Unchanged lines stay in context so you never lose your place.
Code diffs are syntax-highlighted for JSON, JavaScript, Python, HTML, CSS, and dozens of other languages.
JSON formatter, Base64 encoder, JWT decode, hash generator, and 44 other tools. All in one extension.
ArcPanel uses a line-by-line diff algorithm similar to Git's built-in diff. It compares the two texts, identifies insertions, deletions, and modifications, then renders them with color-coded highlights — all locally in your browser.
Yes. You can paste text directly or drag and drop files into each pane. ArcPanel will read the file contents locally and run the diff — nothing is uploaded to any server.
Yes. The diff engine is optimized for performance and can handle files with thousands of lines without freezing your browser. Everything stays fast and responsive.
Yes. You can copy the unified diff output or either side individually. ArcPanel also supports exporting the diff in standard unified diff format for use with Git or patch tools.
49 developer tools, one keystroke away.
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