Text Diff Checker
Compare two texts line by line and see additions and deletions instantly.
All conversions happen in your browser. No data is sent to our servers - see why that matters. Share links encode your input in the URL itself; nothing is stored on a server. Press Cmd/Ctrl + Enter to convert.
How to Compare Two Texts
Paste the original text in the first panel and the changed text in the second. Click Compare (or let auto-convert run) to see a line-by-line diff with a summary of additions and deletions at the top.
Reading the Output
Lines starting with - exist only in the original; lines starting with + exist only in the changed text; other lines are identical in both. This mirrors the unified diff format used by git and most code review tools.
Common Use Cases
Developers diff texts to review config changes before deploying, compare API responses between environments, verify generated output against expectations, and spot edits between document versions. For structured JSON comparison, use the JSON Compare tool instead.
Frequently Asked Questions
How does the diff checker compare texts?
It compares line by line using the longest-common-subsequence algorithm - the same approach used by git diff. Unchanged lines are shown with two spaces, removed lines with a minus, and added lines with a plus.
Can I compare code files?
Yes. Paste any text - source code, configs, SQL, logs - into the two panels. The output uses the familiar unified-diff style that developers already know.
Is there a size limit?
Each input is limited to 3,000 lines to keep the comparison instant in your browser. For larger files, compare focused sections.
Is my text uploaded anywhere?
No. The comparison runs entirely in your browser, so proprietary code and confidential documents are safe to compare here.