Text Diff Tool
Compare two texts and highlight differences. Line-by-line and character-level diff. Useful for code review and document comparison.
The diff shows line changes; the character view narrows further to the exact insertion or deletion. Whitespace-only changes can be ignored, which is usually what you want when reviewing a pull request.
Tool workspace
Compares raw text line by line. Whitespace and letter case count as differences unless ignored below.
Line-by-Line
Compares text line by line to identify added and removed lines.
Character Level
Highlights differences at the character level within changed lines.
How to Compare Text Online
Learn how to compare two texts and highlight differences using a zero-knowledge, client-side tool.
- 1
Enter original text
Paste the original text in the left input box.
- 2
Enter modified text
Paste the modified text in the right input box.
- 3
Click Compare
The tool highlights differences line by line and character by character.
- 4
Review results
View added, removed, and unchanged lines in split or unified view.
Use cases
- 1Review code changes line by line before committing or merging
- 2Compare two versions of a configuration, document, or API payload
- 3Spot whitespace and character-level differences that break exact-match checks
- 4Track what changed in logs or error messages across environments
Frequently Asked Questions
Which diff modes are available?
Line-by-line and character-level comparison, with unified and side-by-side views.
Are my texts uploaded?
No. Comparison happens entirely in your browser.
Can I compare large files?
Large inputs are handled client-side; performance depends on your browser.
Can I compare JSON semantically instead of line by line?
Yes. The JSON mode parses both sides and reports added, removed, and changed keys regardless of key order or whitespace. Line and character modes remain available for plain text.
How large can the inputs be?
Each side accepts up to 1 MB, which keeps the comparison responsive in the browser. Larger inputs are rejected with a clear message rather than freezing the tab.
Related Guides
Related Tools
You are responsible for key management and output validation.