Does this require an existing wallet?

No. A generator should create new random keys locally and should never ask for an existing seed phrase.

Can a vanity pattern prove value?

No. A visible pattern is not proof of safety, ownership quality, or financial value.

Prefix and suffix matching fix exact positions, so they are easy to reason about.

Contains matching can feel more flexible, but it may be less visually prominent.

Vanity address tools work best when the target pattern is short and easy to validate.

Every extra fixed character multiplies the expected work, so a pattern that looks only slightly longer can be much harder.

Generated keys are sensitive. Never upload, log, or share private keys or secret keys.

A visually interesting address does not make a wallet safer and should not be treated as financial advice.