Question 1

What diff algorithm is used?

Accepted Answer

LCS (Longest Common Subsequence) based diff — same approach as professional diff tools.

Question 2

Can I copy the diff?

Accepted Answer

Yes — click Copy Diff to get unified diff format output.

Question 3

How do I check online free?

Accepted Answer

Enter your input above and get an instant result. Free with no sign-up, works on mobile and desktop.

Question 4

What does it check?

Accepted Answer

It validates your input against standard rules instantly. Enter the value above to see the result.

Question 5

Is my data kept private?

Accepted Answer

Yes. Everything runs in your browser. Nothing you enter is uploaded or stored.

Question 6

Is this Text Diff Checker free?

Accepted Answer

Yes, completely free with no sign-up. Use it unlimited times online on any device.