Free Online Text Diff Checker
Paste two blocks of text and instantly see every addition, deletion, and change — highlighted line by line and character by character.
Open the Tool — Free & InstantYour data never leaves your browser
No server processing
All diffing runs locally in your browser using JavaScript. Zero data transmitted.
No logging or storage
We do not store, log, or read your content. Nothing is saved anywhere.
Safe for sensitive content
Confidential code, config files, API keys — safe to compare here.
PII detection on share
Before any share link is generated, your content is scanned for emails, API keys, and tokens — with options to redact or encrypt.
Features
- ✓Side-by-side and unified diff views
- ✓Character-level change highlighting
- ✓Ignore whitespace option
- ✓Added and removed line counters
- ✓Shareable links — share any diff with a URL
- ✓File upload support — drag and drop text files
- ✓100% in-browser, nothing sent to a server
- ✓Works on any device, no install needed
Frequently Asked Questions
How do I compare two pieces of text online?
Paste your original text in the left panel and the modified text in the right panel. The diff is computed instantly in your browser — changed lines are highlighted red (removed) and green (added).
Is my text kept private?
Yes. Everything runs entirely in your browser. Your text is never uploaded to any server, stored, or logged. It is safe to use with sensitive or confidential content.
Can I share a diff with someone else?
Yes. Click the Share button to generate a link. The diff content is compressed and stored in the URL itself — no server involved. You can also encrypt the link with a password before sharing.
What is the difference between side-by-side and unified view?
Side-by-side shows original and modified text in two columns so you can read them in parallel. Unified view shows a single stream with + and − markers, similar to git diff output.
Can I compare text files instead of pasting?
Yes. Click the File button above either text panel or drag and drop a .txt file directly onto the panel.