Text Diff Checker – Compare Texts Line by Line
Paste an original and a revised version to see which lines were added, removed or kept. Your text stays in the browser.
Paste both versions to compare.
Supports up to 1,000 lines and 100,000 characters per side. Switch between line comparison and word-level highlighting. Word mode normalizes whitespace and supports 500 words per side.
How to compare two texts
- Paste your original paragraph, draft, log or configuration into the first box.
- Paste the revised version into the second box.
- Click Compare text to compute the line differences.
- Review added and removed lines, or copy the annotated version for review.
What do the highlighted changes mean?
Added lines exist in the revised version but not in the matching location of the original. Removed lines appeared in the original. Unchanged lines provide context. A rewritten line generally appears as one removal plus one addition. Lines are matched in order using a longest-common-subsequence algorithm.
Ignore capitalization and whitespace
The optional Ignore letter case setting treats Release and release as equivalent for matching. Ignore whitespace collapses runs of spaces and trims the ends of each line. The display still shows the revised line when the normalized versions match.
When is a line diff useful?
Compare two versions of a product description before publishing, audit changed configuration lines, inspect updated terms, or verify a pasted transcript against an earlier draft. Line matching is deliberately simpler than full document revision tracking: moved blocks may appear as deletions and additions, and the tool does not interpret the meaning of an edit.
Privacy and large inputs
All comparison runs locally in your browser. We do not upload entered text, store revisions or generate shareable URLs containing your content. To keep the workspace responsive, each input is limited to 1,000 lines and 100,000 characters. For much larger files or character-level code diffs, use a dedicated version control or diff program.
Frequently asked questions
Can I compare two code snippets?
Yes, if you paste them as plain text. This tool does not parse programming languages or ignore syntax-specific changes.
Why are edited lines shown twice?
The comparison works at the line level. A changed line can appear as an old line removed and a new line added.
Does PostChars save either version?
No. Entered text stays in browser memory while the page is open.