Never paste a live password or passphrase into a forum post. For a sensitive account, prefer a unique, sufficiently long value generated and stored by a trusted password manager.
A strength meter can catch obvious weakness, but it cannot prove uniqueness or that a phrase has never leaked. Avoid famous quotations and predictable substitutions. Enable multifactor authentication where available, and keep recovery codes private.
Are you choosing a new phrase or assessing an already-used one?