Token-2022 vs SPL Token: Why Pump.fun Tokens Are Different

Solana has two token programs. The original SPL Token program runs almost every token created over the years; Token-2022 (also called Token Extensions) is its successor with optional features built in. New pump.fun tokens are Token-2022 mints, while LetsBonk and Bags tokens use SPL Token. For most holders it makes no difference - but for anyone building, checking or bundling tokens, a few details matter.

The two programs

• SPL Token - program TokenkegQfeZyiNwAJbNbGKPFXCWuBvf9Ss623VQ5DA. A mint account is a fixed 82 bytes: supply, decimals, mint authority, freeze authority. Metadata (name, symbol, image) lives in a separate Metaplex metadata account.
• Token-2022 - program TokenzQdBNbLqP5VEhdkAS6EPFLC1PHnBqCXEpPxuEb. Same base layout, plus optional extensions appended to the mint or token accounts.

What a pump.fun mint carries

We read a live pump.fun mint. It has exactly two extensions: metadataPointer and tokenMetadata. In other words, the name, symbol and metadata URI are stored inside the mint account itself instead of a separate Metaplex account. That is why the mint account is larger (420 bytes in the token we checked vs 82 for SPL Token). Mint and freeze authority are both revoked. No transfer fee, no transfer hook, no permanent delegate.

Extensions worth knowing

Token-2022 offers extensions that change how a token behaves. The ones a buyer should look for:

• Transfer fee - every transfer pays a percentage to an authority. Sells net less than expected.
• Transfer hook - a custom program runs on every transfer and can block it.
• Permanent delegate - an address that can move or burn tokens from any holder's account.
• Default account state frozen - new token accounts start frozen until thawed.

None of these are on pump.fun mints, and LetsBonk and Bags mints use SPL Token, which can't have them. A token outside these launchpads deserves a look at its extensions - together with the authorities covered in mint and freeze authority explained.

What changes in practice

• Token accounts. A holder's token account is created by the program that owns the mint. The associated token address is derived with that program's id, so a tool that assumes SPL Token computes the wrong address for a pump.fun token and sees an empty balance.
• Rent. Token-2022 token accounts can be slightly larger than SPL ones because of extension data, so rent can be a little higher (rent explained).
• Older tools. Some older wallets and scripts only understood SPL Token and showed Token-2022 balances as missing. Current wallets and explorers handle both.

SolBundle's launch, Terminal and tools detect the program of each mint and use the right one, so pump.fun, LetsBonk and Bags tokens all show correct balances.

Frequently asked questions