How to Identify ERC-20 ERC-721 and Other Token Standards on an Explorer
Block explorers label token standards in different ways. Sometimes the label is explicit. Other times it is buried in code. This guide shows you how to find those labels and - more importantly - how to verify them yourself.
The skill matters because explorers are not infallible. They pull data from on-chain sources, but their interpretation can lag or err. Independent verification keeps you in control.
What token standards look like on EVM explorers
Etherscan handles Ethereum. BscScan handles BSC. Both work the same way.
When you view a token contract on Etherscan, look for the "Contract" tab. Under it, you will see a sub-tab called "Read Contract." This is where the standard reveals itself.
ERC-20 tokens show functions like name(), symbol(), decimals(), totalSupply(), and balanceOf(). If the contract includes transfer() and transferFrom(), it is a standard ERC-20.
ERC-721 tokens (NFTs) add functions like ownerOf(), tokenURI(), and safeTransferFrom(). The explorer sometimes labels these as "ERC-721" in the token type column. That label comes from the contract's bytecode and ABI detection.
ERC-1155 tokens mix both. They use balanceOf(), safeTransferFrom(), and uri(). Explorers may show "Multi Token" or "ERC-1155" as the type.
BEP-20 tokens on BSC are identical to ERC-20 in structure. The same read contract functions apply. The label may say "BEP-20" but the standard is the same.
Where the label comes from
The label on an explorer is not magic. It is derived from the contract's deployed bytecode. The explorer scans for known function signatures. If it finds transfer(address,uint256), it assumes ERC-20. If it finds ownerOf(uint256), it assumes ERC-721.
That is why you verify.
How to verify independently
Open the contract on Etherscan or BscScan. Click the "Contract" tab. Then click "Read Contract."
You will see a list of functions. The explorer shows these functions because the contract source code is verified. If the source is not verified, you see only the bytecode.
Check for these interfaces:
- ERC-20: Must have
totalSupply(),balanceOf(address),transfer(address,uint256). Optional but common:symbol(),decimals(). - ERC-721: Must have
ownerOf(uint256),balanceOf(address),safeTransferFrom(address,address,uint256). Look fortokenURI(uint256). - ERC-1155: Must have
balanceOf(address,uint256),safeTransferFrom(address,address,uint256,uint256,bytes).
If the contract claims to be ERC-20 but lacks totalSupply(), be suspicious. If it claims ERC-721 but has no ownerOf(), something is off.
Solana: A different model
Solana does not use ERC standards. It uses the SPL Token Program.
On Solscan (the primary Solana explorer), every token uses the same underlying program: the SPL Token Program. The standard is detected by checking if the mint account is owned by that program.
SPL Tokens (fungible tokens) show a "Mint" address. The explorer lists them as "Token" or "SPL Token." There is no separate "ERC-20" label.
SPL NFTs use a different variation. Solana NFTs are technically SPL tokens with supply of 1 and decimals of 0. The explorer may show "NFT" in the type column, but the underlying program is the same.
To verify on Solscan:
1. Open the token's mint address.
2. Look at the "Token Program" field. It should show "Token Program" with a program ID of TokenkegQfeZyiNwAJbNbGKPFXCWuBvf9Ss623VQ5DA.
3. Check the supply. If supply is 1 and decimals is 0, it is likely an NFT.
A Concrete Example
The token sonny (staring robot) lives on Solana at address FAJW358HjJ2mHXSHbHyxghfVGzX5SBoupdjRr2y9pump. As of August 31, 2026, it has three trading pairs. Liquidity sits at $25,952.03. Volume over 24 hours is $0.22 with exactly one transaction.
To check its standard:
- Open Solscan and paste the mint address.
- The token program will be TokenkegQfeZyiNwAJbNbGKPFXCWuBvf9Ss623VQ5DA.
- Decimals will appear in the metadata.
This confirms it is a standard SPL token. No extra verification needed beyond the program ID.
Why This Matters
Explorers are tools, not authorities. They make assumptions. You can trust the label, but only if you check the functions yourself. That takes thirty seconds.
Do it once. Then you know.
Not financial advice. sonnyonsol.xyz publishes market data and general information about staring robot. Crypto assets are volatile and you can lose everything you put in. Nothing here is a recommendation to buy, sell or hold, and we make no price predictions.
Prices are sourced from third parties and may be delayed or wrong. Verify anything you intend to act on against a primary source.