Text Tools
Text Diff Checker
Compare two text blocks line by line and highlight additions, removals and unchanged lines.
Processed locally — your data never leaves this browser.
Example input and output
Line change
Old:
alpha
beta
New:
alpha
gamma alpha
- beta
+ gammaHow to use Text Diff Checker
Paste or enter your two text blocks, adjust any options, then run the tool. The result appears in the output panel where you can copy or download it.
Related guides
What this tool does
The Text Diff Checker compares two pasted text blocks locally and produces a readable unified-style line diff for copy review, QA and debugging. It is free to use and designed for technical workflows where pasted data should stay private.
Common use cases
- Compare copied config
- Review generated output
- Spot differences in logs or fixtures
Privacy and security
Processed locally — your data never leaves this browser. Lumarc DevTools does not include a backend, account system or hidden analytics in this initial release.
Limitations
- This first version compares lines and does not provide a side-by-side merge editor.
Frequently asked questions
Does this upload either text block?
No. Both versions are compared locally in your browser.