Diff Checker
Compare two blocks of text and see added and removed lines highlighted, with a running count of changes. Runs entirely in your browser.
How it works
- 1
Paste your input
Type or paste your data into Diff Checker.
- 2
Adjust options
Tweak the available settings — the output updates as you type.
- 3
Copy the result
Copy the output to your clipboard or download it as a file.
Common uses
- Compare two versions of a config to spot what changed.
- See added and removed lines between two text blocks.
- Check a pasted diff before applying it.
About the Diff Checker
Compare two blocks of text and see added and removed lines highlighted, with a running count of changes. Runs entirely in your browser.
Diff Checker is part of a free, privacy-first toolkit. Everything is computed instantly on the client, so your data never leaves the page — useful when you're working with sensitive payloads.
Because diff checker works without any sign-up or installation, you can use it as often as you like and it's always available — on desktop or mobile, and even offline.
Explore more developer tools, or try JSON Formatter · JSON Validator.
Related tools
Related guides
Diff Checker — FAQ
It runs a line-level longest-common-subsequence diff, highlighting added lines in green and removed lines in red with a running change count.