Text Diff
Compare two texts line by line with side-by-side or unified view, plus add/remove/change counts.
How to use it
- Paste the original text on the left and the changed text on the right.
- Click Compare (or press Ctrl/Cmd+Enter in either panel).
- Switch between Side by side (paired rows) and Unified (− / + lines) views.
- Read the counter line:
+added,−removed,~changed rows.
Common use cases
- Reviewing config edits — diff two versions of a
.env, YAML or JSON file before committing. - Checking copy changes — compare a paragraph before and after an edit to see exactly what moved.
- Log comparison — paste two log excerpts and spot the lines that differ.
- Teaching and docs — show a before/after pair when explaining an API change.
Why it stays private
The diff runs as a local longest-common-subsequence pass in your browser. Sensitive configs, contracts and logs never leave your device.
FAQ
Q: How large can the inputs be? A: Up to 4000 lines per side. The comparison is a full dynamic-programming pass, so beyond that it asks you to trim the input instead of freezing the tab.
Q: Does it compare within a line (word-level)? A: No — it pairs changed lines and shows them as a −/+ pair in unified view. Line granularity keeps results predictable for configs and code.
Q: Are whitespace differences shown? A: Yes, exactly as they are. Trailing spaces show up as a changed line, which is usually what you want when reviewing edits.
Your data stays on this device
Text Diff runs 100% locally. Everything you paste or drop is processed by your own browser and never transmitted. Nothing is stored on our servers — close the tab and it is gone.
Nothing you type is sent to a server, logged, or used for analytics. The page works even with your network disconnected after first load.