Cronos

Cronos are EVM and PoS Networks Powered by CRO

Cronos are blockchain networks where the EVM runs Ethereum-style programs and gas means the CRO fee paid for computation. The main Cronos EVM chain uses chain ID 25, accepts Ethereum wallets and smart contracts and supports DeFi, tokens, NFTs and games. Cronos POS handles native CRO transfers and staking, while the Cronos zkEVM Alpha is winding down ahead of its scheduled 2027 closure.

Key takeaway: They are blockchain networks led by an EVM-compatible chain for DeFi and Web3 apps, where CRO pays gas and EVM support lets Ethereum smart contracts run with minimal changes.

The network label controls where CRO arrives

Because CRO exists on several networks, the selected withdrawal or bridge network determines where the asset arrives and which wallet address and fee currency apply. Cronos EVM uses chain ID 25 and 0x addresses whose payloads are 20 bytes, displayed as 40 hexadecimal characters after the prefix. Cronos POS uses cro1 addresses and represents one CRO as 100,000,000 basecro, while ERC-20 CRO on Ethereum sits on chain ID 1. A shared ticker doesn't merge those ledgers; the sending service must support the exact destination network.

How does CRO pay Cronos gas?

When a transaction targets Cronos EVM, CRO pays for the gas units consumed by EVM execution, and the fee equals gas used multiplied by the effective gas price.

The base fee and denomination

The chain recalculates a base fee as blocks fill, using a fee-market design similar to EIP-1559. CRO uses 18 decimal places on the EVM chain, so one CRO contains 1,000,000,000,000,000,000 base units and one gwei equals 0.000000001 CRO.

Contract calls consume more gas

Plain CRO sent between two externally owned accounts has 21,000 gas as its standard intrinsic requirement. A VVS Finance swap or Tectonic deposit executes several contract operations, so the wallet estimates a larger gas limit. A token approval also consumes a separate transaction when no sufficient allowance exists.

Worked example

Worked example: take a hypothetical simple-transfer estimate of 21,000 gas and a hypothetical effective price of 500 gwei. Multiplication produces 10,500,000 gwei, which converts to 0.0105 CRO because 1,000,000,000 gwei equals one CRO. The sender therefore needs the transfer amount plus 0.0105 CRO in the wallet. A wallet's gas limit is a ceiling, not an automatic charge; the receipt records actual gas used. Changing either input changes the answer, while CRO's 18-decimal conversion remains fixed.

Ethereum execution over Cosmos infrastructure

Because Cronos EVM combines an Ethereum execution layer with Cosmos components, it accepts familiar smart-contract tooling while reaching consensus through a separate validator architecture underneath, as covered in Using Cronos.

That split explains why Solidity code ports cleanly while network selection, fee payment and bridge routes remain specific to this chain.

EVM execution

At the execution layer, Solidity contracts expose the same application binary interface patterns used on Ethereum. EVM words are 256 bits, function selectors occupy 4 bytes and transaction hashes are 32 bytes. MetaMask, Trust Wallet, WalletConnect, Hardhat and Ledger therefore use familiar signing and JSON-RPC flows once chain ID 25 is selected. Compatibility reduces code changes for developers and interface changes for users, but a deployment on the chain has its own contract address and state. An ERC-20 balance on Ethereum doesn't automatically appear in its EVM counterpart. The ledger boundary remains absolute.

Consensus and blocks

Cronos EVM mainnet uses EVM chain ID 25 and Cosmos chain identifier cronosmainnet_25-1. Cosmos SDK supplies the application framework, while CometBFT Byzantine fault tolerant consensus orders blocks under Cronos EVM's proof-of-authority validator model. Validator signatures provide deterministic finality once a block commits. This design exchanges open validator entry for a more constrained authority set and short confirmation times.

IBC and token movement

IBC gives the Cosmos side a packet-based route between compatible chains, while EVM contracts receive token representations they understand. Cronos Bridge uses that mechanism for supported movements between Cronos POS and Cronos EVM; routes involving Ethereum rely on different bridge infrastructure. CRC-20 is the ecosystem's name for its ERC-20-compatible fungible token format, while ERC-721 and ERC-1155 cover unique and multi-token assets. The standards govern contract interfaces, not asset identity. A bridge transfer changes the chain and representation recorded in the wallet, so the route must match the receiving application, which is walked through in Cronos working with limits in practice.

DeFi, NFTs and games on the EVM chain

When the goal is on-chain trading, lending, liquid staking or gaming, Cronos EVM supplies composable contracts that share one wallet account and one CRO gas balance.

VVS Finance provides automated-market-maker pools and swaps, so price execution comes from token reserves rather than an order book. Tectonic supports overcollateralized lending markets, where supplied assets back borrowing and positions face liquidation thresholds set by each market. Veno Finance represents liquid-staked CRO through LCRO, separating a transferable receipt from the underlying staking position. Fulcrom offers perpetual-contract trading, which introduces collateral, funding and liquidation mechanics. Games and NFT applications use ERC-721 or ERC-1155 ownership records. Each use case adds its own contract fees, pool depth and position rules on top of network gas paid in CRO.

What do you need before using Cronos?

When a wallet supports custom EVM networks and holds native CRO on chain ID 25, it has the two prerequisites for entering Cronos EVM applications.

Select an EVM wallet

MetaMask, Trust Wallet and Onchain Wallet connect to the EVM chain, while Ledger signs through a compatible wallet interface. The same private key derives the same 20-byte account across EVM networks, so the address looks identical even though each chain records a separate balance.

Fund the gas balance

Withdraw or bridge CRO specifically to Cronos EVM, then leave enough native CRO outside application positions for fees. Wrapped CRO, or WCRO, follows the CRC-20 contract interface and unwraps one-to-one into native CRO, yet the WCRO token balance doesn't pay protocol gas directly.

Read the first receipt

When no allowance exists, an ERC-20 swap requires two transactions: an approval and the swap itself. Each processed outgoing transaction advances the account nonce by 1, including a contract call that reverts. Cronos Explorer then shows status, gas used, effective gas price and emitted logs, which separates the network charge from the application's token movements.

Cronos suits CRO-centered EVM activity

When users already hold CRO and want Ethereum-style DeFi within that asset ecosystem, Cronos EVM offers the clearest fit, though validator and liquidity trade-offs remain.

Proof of authority gives Cronos EVM fast finality, yet validator admission is more constrained than on Ethereum's proof-of-stake network. DeFi positions also inherit contract, collateral, oracle and liquidity risk from Tectonic and Fulcrom; CRO gas doesn't remove those mechanics. Cronos POS applies a 28-day unbonding period to directly delegated CRO. The separate Cronos zkEVM Alpha is deprecated, its bridge has disabled deposits and the network is scheduled to close on June 3 2027. Cronos works best when the available applications and CRO fee model match the intended transaction, with EVM for contracts and POS for validator delegation.

Ethereum, Base, Arbitrum and BNB Smart Chain as alternatives

When Ethereum-native settlement, rollup execution or BNB-denominated gas matters more than CRO integration, Ethereum, Base, Arbitrum One and BNB Smart Chain provide direct alternatives. Ethereum uses chain ID 1 and ETH gas; Base uses 8453 and Arbitrum One uses 42161, with both settling to Ethereum and charging ETH. BNB Smart Chain uses chain ID 56 and BNB. Cronos remains distinct through native CRO gas and its Cosmos SDK and IBC architecture, so the deciding constraint is where the application and assets already live.