What mint authority and freeze authority mean on Solana
Every SPL token on Solana has two optional "authorities" set by whoever created it. They are the two settings rug checkers look at first.
Mint authority
The mint authority is a wallet allowed to create (mint) new tokens. If it is active, the supply is not fixed: the holder can print more tokens whenever they want and sell them, diluting everyone else.
When the mint authority is revoked (set to none), nobody can ever mint more. The supply is permanently fixed. Rug checkers show this as "mint authority revoked" or "supply fixed".
Freeze authority
The freeze authority can freeze token accounts, which stops a wallet from moving or selling its tokens. Some legitimate stablecoins keep it for legal reasons. For a memecoin, an active freeze authority is a serious red flag because it can trap buyers.
Metadata update authority
Separately, the token's name, ticker and logo live in metadata that may still be editable. A changeable name is less dangerous than an active mint, but it allows a coin to impersonate another later.
How to check
Paste the token address into a free rug check. It reads the authorities straight from the chain and tells you in plain words whether each one is revoked or still active.
FAQ
What does "mint authority revoked" mean?
Nobody can create more of the token. The supply is fixed forever.
Is an active freeze authority always a scam?
Not always. Regulated stablecoins such as USDC keep one. For a memecoin, it is a big warning sign because the creator could stop you from selling.
Do pump.fun tokens have mint authority?
pump.fun revokes mint and freeze authority at launch. The bigger risks there are holder concentration, bundled wallets and the creator dumping.
More: Red flags glossary · Launch checklist · Rug Screener
Educational only, not financial advice.