Text Diff Checker
Compare two texts side-by-side with color-coded additions, deletions and changes. No data leaves your browser.
- 100% free
- No sign-up
- No limits
- Instant results
- Side-by-side comparison with line numbers
- Color-coded: green (added), red (removed), yellow (changed)
- Summary stats for quick overview
- Copy diff output in unified format
- Pure client-side processing
What is Text Diff Checker?
A text diff checker compares two versions of text and highlights the differences between them.
It works line by line, identifying which lines were added, removed, changed or left unchanged. This is essential for writers reviewing edits, developers comparing code versions, translators checking localized text, and anyone who needs to spot changes between two documents. Our tool uses color-coded highlighting — green for additions, red for deletions and yellow for modifications — making differences instantly visible. The comparison runs entirely in your browser using JavaScript, so your sensitive documents are never uploaded to any server. Unlike command-line diff tools, this visual interface shows both versions side by side with line numbers, making it easy to trace exactly what changed and where.
How to use Text Diff Checker
- 1
Paste the original text
Enter your original or baseline text in the left textarea.
- 2
Paste the modified text
Enter the updated or modified version in the right textarea.
- 3
Review the diff
The tool instantly highlights differences with colors. Green means added, red means removed and yellow means the line was changed.
- 4
Copy the result
Click Copy diff to get a unified diff format you can share or save.
Everything this tool
does for you
- Line-by-line text comparison
- Color-coded additions, deletions and changes
- Side-by-side view with line numbers
- Summary statistics (added, removed, changed, unchanged)
- Copy diff output in unified format
- Works with large documents
- Pure client-side — your text stays private
Related free tools
Frequently asked questions
This tool fixed one thing.
Now fix the whole site.
Our scanner runs 240+ checks across 10 audit areas, ranks every issue by the score points it costs, and hands you the code to paste.
Run a free audit