What Text Diff Does
Text Diff compares two versions of a document and shows exactly what changed. Added lines are highlighted in green, removed lines in red, and unchanged lines stay neutral. This is useful for reviewing edits, comparing configuration files, checking generated output or verifying that a replacement produced the expected result.
Options
- Ignore case: treat uppercase and lowercase as equal.
- Ignore whitespace: collapse spacing before comparing.
- Swap: reverse the original and modified panels.
The stats show additions, deletions, unchanged lines and a similarity percentage,
giving you a quick sense of how much the text changed. The diff can be copied or
downloaded as plain text with + and - prefixes.
How to Read the Diff
Lines prefixed with + exist only in the modified version. Lines prefixed
with - exist only in the original. Lines with two spaces are unchanged.
The comparison is line-based, so a small edit inside a line appears as a removed line
and an added line rather than a character-level change.
Common Workflows
Compare an old and new version of a contract, check what changed between two API responses, review edits before publishing, or verify the output of Find and Replace. For whitespace cleanup before comparing, use Text Minifier.
Limitations
- Comparison is line-based; word-level changes are shown as whole-line changes.
- Very large files can be slow and may exceed browser memory limits.
- Different line endings or encodings can create noisy differences.
- The similarity percentage is a heuristic, not a legal or forensic measure.
Line Endings and Encoding
Different line endings, trailing spaces or encodings can create noisy differences that are not meaningful content changes. Normalize the text with Text Minifier before comparing, or enable “Ignore whitespace” when spacing should not count. Check for a byte-order mark if the first line always appears different.
Comparing Code and Config
Text Diff is useful for reviewing configuration changes and small code edits, but it is not a replacement for a version-control diff with syntax awareness. For large code changes, use Git or a code-aware diff tool; use this page for quick comparisons of snippets, environment variables or API responses. Version control provides history and rollback; this tool provides a quick visual check.
Privacy
The comparison runs locally in your browser. Your texts are never uploaded, which makes the tool suitable for private documents and internal data. For related work, use the Find and Replace tool or Text Minifier.