Solana does not have one token standard. It has two token programs: the original SPL Token program that almost every major asset uses, and Token-2022 (also marketed as "Token Extensions"), a richer successor. Every mint belongs to exactly one of them, and the difference matters more than most people expect.
Two programs, two program IDs
On Solana, tokens are not smart contracts you deploy yourself, the way ERC-20s are on Ethereum. All tokens are accounts owned by a shared, audited program. The original program lives at the address starting Tokenkeg…; Token-2022 lives at TokenzQd…. A mint created under one program can never migrate to the other: the choice is permanent at creation time.
This is why "which program owns this mint?" is the first question worth asking about any unfamiliar Solana token. Our token lookup reads it straight from the chain and labels the result SPL Token or Token-2022.
Why a second program exists
The original SPL Token program is deliberately minimal: mint, transfer, burn, freeze, delegate. Years of real-world use produced a wish list (fee-on-transfer tokens, confidential amounts, richer metadata), but the program is load-bearing infrastructure holding billions of dollars, so bolting features onto it in place was judged too risky.
Token-2022 is the clean answer: a superset of the original instruction set, deployed as a separate program, with new behavior packaged as opt-in extensions attached per mint or per account. Old assets stay untouched; new assets choose their feature set at creation.
The extensions that matter in practice
A few extensions account for most real-world usage:
The compatibility catch
Token-2022 is not a drop-in upgrade for tooling. Associated token account derivation includes the program ID, so a wallet that assumes the classic program will derive the wrong address for a Token-2022 mint. Older dapps, indexers, and exchange integrations may not recognize Token-2022 balances at all, and a program that hard-codes Tokenkeg… will simply fail.
The ecosystem has largely caught up (major wallets and DEXes handle both), but "largely" is doing real work in that sentence. Before moving significant value in a Token-2022 asset, confirm the receiving side supports it. Sending to a platform that only understands classic SPL Token is a support-ticket generator.
What to check before interacting with a mint
Three reads cover most of the risk. First, the owning program: classic or 2022. Second, the authorities: a live mint authority means supply can be inflated, and a live freeze authority means your account can be frozen (both are normal for stablecoins, notable for "community" tokens). Third, for Token-2022 mints specifically: which extensions are enabled, because a permanent delegate or a transfer hook changes what "owning" the token means.
All three are on-chain facts, not marketing claims. Thirty seconds with a lookup tool reads them directly.