Text Diff Checker
Runs in your browser. Your files never leave your device.
How we keep your files private
How to use Text Diff Checker
- Paste the original text in A and the changed text in B.
- Read the highlighted result: green lines are added, red lines are removed.
- Copy lines you need from the output.
Common uses
- Comparing versions of an essay or contract.
- Spotting changes in configuration files or code.
- Checking two lists for differences.
About this tool
Paste two versions of a text and see added lines highlighted in green and removed lines in red. The comparison is line by line, which suits code, configuration files and lists. Up to 2,000 lines per side are supported, and nothing is uploaded.
Worked example
Comparing “The cat sat on the mat” with “The cat slept on the mat” highlights sat as removed and slept as added, and leaves the other words unchanged. Use it to review edits to a contract, essay or configuration file.
Common problems and fixes
- Everything shows as different.
- Line endings (Windows versus Mac or Linux) or invisible spaces can make every line differ. Normalise them first.
- Moved paragraphs show as delete plus insert.
- A line-based comparison does not detect moves. Compare the moved section on its own.
- The result is hard to read.
- Compare smaller sections at a time for long documents.
Next steps
Frequently asked questions
Is the comparison line by line?
Yes. Lines are compared whole, so a small edit inside a line shows as one removed and one added line.
How large can the texts be?
Up to 2,000 lines per side.
Are my files uploaded to a server?
No. Everything runs inside your browser on your own device, so your files and text are never sent anywhere.
Is it really free?
Yes. There is no sign-up, no watermark and no limit on how often you use it.
Does it work on my phone?
Yes. It works in any modern browser on phones, tablets and computers. Very large files may be slow on older phones.
Does it work offline?
Once the page has loaded, most tools keep working without a connection, because processing happens on your device.