What algorithm is used?

A longest common subsequence (LCS) based diff algorithm that compares text line by line — similar to what Git uses for showing changes.

Paste the file contents into the text boxes. The tool handles text comparison — for binary files, use a dedicated diff tool.

Is there a size limit?

No hard limit, but very large texts (100,000+ lines) may be slow since the diff runs in your browser. For most practical uses, it's instant.

No. All comparison happens locally in your browser.

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Developer Tools

Compare two texts side by side and see exactly what was added, removed, or changed. Line-by-line diff with color highlighting.

OriginalModified

Paste text into one or both boxes, then compare the changes.