Productivity
Text Diff Checker
Compare two blocks of text line by line and identify added, removed, and unchanged lines.
How to use this tool
- Paste the earlier version into Original text and the revised version into Changed text.
- Select Compare text to align matching lines and identify additions and removals.
- Read the summary cards for a quick count, then inspect the colored line results below.
- Make further edits in either input and compare again when ready.
Practical examples
Check which steps changed between two versions of an operating procedure.
Compare an old and new product list to spot added or removed entries.
Review edits to a plain-text email template before publishing it in an automation.
Common mistakes to avoid
- Expecting a word-level highlight when the tool compares complete lines.
- Ignoring trailing spaces or capitalization differences that make lines unequal.
- Reordering many lines and assuming they will all count as unchanged.
- Using a browser comparison instead of a version-control review for complex source-code changes.
Useful internal links
Frequently Asked Questions
How does the comparison work?
The checker compares complete lines and finds a shared line sequence, then marks the remaining lines as added or removed.
Does it compare individual words?
No. This tool is intentionally line-based, making it useful for lists, notes, configuration, and paragraph revisions.
Are spaces and capitalization significant?
Yes. A difference in case, punctuation, or whitespace means the complete line is treated as changed.
Is my text sent to a server?
No. The comparison runs locally in your browser and the tool does not submit either text block.
How the comparison works
- The tool compares complete lines with a longest-common-subsequence approach and marks each line as added, removed, or unchanged.
- Reordered lines can appear as a removal plus an addition because the comparison is sequence-based rather than semantic or word-level.
- Each side is capped at 1,000 lines to reduce the chance that the quadratic comparison table freezes a browser tab on very large documents.
Review line changes in context
Who this helps
Useful for comparing lists, notes, procedures, configuration, and other plain text where line order matters.
A practical workflow
Normalize formatting, compare the two versions, inspect additions and removals, then verify important changes against the source document.
Important limitation
The comparison is line-based, not word-aware, and reordered lines may appear as separate removals and additions.
Privacy note
Both versions remain in the browser. Anonymize contracts, credentials, and private records before comparison.