Diff Checker

The Developer Diff Checker is optimized for code: it supports syntax-aware diffing, handles indentation changes separately, and offers unified diff format output (patch format). The Text Diff Checker focuses on prose comparison with word-level highlighting. Choose this tool for code reviews and patch generation.

The tool offers side-by-side (split) view showing both versions with aligned line numbers, unified view showing changes in a single column with +/- prefixes, and inline view highlighting changes within each line. Switch between views depending on your preference and the type of changes.

Yes — toggle "ignore whitespace" to suppress differences caused only by indentation, trailing spaces, or blank lines. This is useful when comparing code reformatted by different editors or linters. You can also choose to ignore only leading whitespace or only trailing whitespace.

Yes — click "Export as Patch" to generate a standard unified diff format compatible with git apply, patch, and other tools. The output includes file headers, context lines, and change markers (+/-) that can be applied to transform one version into the other.

The tool runs in your browser and handles files up to several hundred kilobytes efficiently. Very large files (multiple MB) may slow down the diff computation and rendering. For very large file comparisons, command-line tools like git diff or Beyond Compare are more suitable.