Is it correct to say “I don’t see any difference”?

Yes. “I don’t see any difference” is correct and natural.

It means that two things look, seem, or feel the same to you.

Examples:

• I don’t see any difference between the two designs.

• I can’t see any difference in the results.

• I don’t notice a difference after the update.

You can also say “I don’t see any differences” if you expected several differences but did not find any.