Text Diff Checker
Compare two blocks of text and highlight the differences line by line — 100% in your browser.
Enter text in both panes to see the differences.
About Text Diff Checker
Paste your original and changed text and the differences are highlighted instantly: added lines in green, removed lines in red, with inline word-level highlighting so you can see exactly which words changed within a line. Switch between a side-by-side and a unified view, and see a running count of additions and deletions.
Use the ignore-case and ignore-whitespace options to focus on meaningful changes. The comparison uses a longest-common-subsequence diff and runs entirely in your browser — your text is never uploaded, which makes it safe for code, contracts and other sensitive content.
How to use Text Diff
- Place the original text in one panel and the revised text in the other.
- Inspect added and removed lines and word-level changes before copying either version.
Limitations and common mistakes
A textual difference is not a semantic code review. Two different strings can mean the same thing, and a tiny change can have a large effect in code.
Check whitespace and newline conventions when unexpected changes appear. For large files, compare a smaller relevant section to keep the browser responsive.
The tool processes its input locally on your device. Read our privacy policy for analytics, storage and network details.
Spot a one-word change
A: The quick brown fox B: The quick red fox
Line 1 changed: “brown” → “red” (highlighted inline)
Identical lines are shown for context; only the differing words are marked.
Frequently asked questions
Does it highlight changes within a line?
Yes. When a line is modified, a word-level diff highlights exactly which words were added or removed, not just the whole line.
Can I ignore case or whitespace?
Yes. Toggle “Ignore case” and “Ignore whitespace” to treat differences in capitalization or spacing/indentation as equal.
What's the difference between side-by-side and unified view?
Side-by-side shows the two texts in parallel columns; unified stacks removals and additions in a single column with - and + markers, like a code review diff.
Is my text uploaded to a server?
No. The entire comparison happens locally in your browser, so nothing is transmitted or stored.
For related tasks, explore Regex Tester and Word Counter. Their guides explain the different inputs, assumptions and output formats.