About this tool
What does it do?
It compares two texts line by line and highlights insertions, deletions and modifications — the fastest way to review what actually changed between two versions of code, config, prose or data.
How to use it
- Paste the original and the modified text side by side.
- Changed lines highlight; identical context stays dim.
- For structured data (JSON/XML), prefer the dedicated structural diffs.
Examples
- Reviewing a .env change before deploying.
- Spotting what an update changed in a 200-line SQL migration.
- Comparing OCR output against the source scan.
Important limitations
- Line-based: a reworded paragraph shows as delete+insert, not as an edit.
- Whitespace-only differences can hide real changes — normalize when it matters.
- For JSON, key order and formatting noise make structural diff far more precise.
Privacy
Diffing is local. Diffs often contain secrets on both sides — neither side leaves your browser.
Frequently asked questions
Why is everything marked changed?
Line endings (CRLF vs LF) or trailing whitespace differ. Normalize both sides first.
Word-level diff?
Line diff first, then inspect within changed lines — most reviewers work this way.
Can I compare files?
Paste their contents; for very large files compare focused sections.