Transaction Simulator
Send an Ethereum transaction to the simulator before you broadcast it, and see how it will behave on chain: whether it succeeds or reverts, the gas it uses and the fee, without paying a network fee. Mainnet and Sepolia.
curl -X POST https://rest.cryptoapis.io/simulate-transactions/evm/ethereum/mainnet \ -H "Content-Type: application/json" \ -H "X-API-Key: YOUR_API_KEY" \ -d '{ "data": { "item": { "amount": "0.123", "gasLimit": 84000, "gasPrice": "47125353", "inputData": "0xa9059cbb000000000000000000000000392214…", "maxFeePerGas": "60000000000" } } }'
{
"hash": "0xbedfba55a8ef9342d1fe70e1e9adefad20aca7c164b072a648b1bb95d5a6b631",
"timestamp": 1669627454,
"status": "0x1",
"gasUsed": 21000
}
Blockchain Transaction Simulator
Reduce Network Fees
Optimize gas fees by adjusting transaction parameters. Calculate transaction fees accurately, manage gas consumption expectations, and eliminate unnecessary gas expenses.
Prevent Gas Failure
Running out of gas or high gas fees can result in costly failures. Identify and prevent these issues before they occur with our Blockchain Transaction Simulator.
Detect Еrrors & Improve Security
Detect and prevent transaction failures and reverts even in the preparation stage of transactions. Identify potential risks in transactions, smart contracts, and other blockchain activities associated with overall stability and security.
Realistic Mainnet Simulation
Experience authentic mainnet results without the risk or expense of actual on-chain transactions. Gain precise insights into transaction behavior with our risk-free simulation.
Improve User Experience
Provide deeper and meaningful insights to your dApp users regarding their interactions with your system. Create a simplified feedback to enhance users experience and engagement.
Efficient DApp Testing & Optimization
Simulate transactions to assess confirmation times, fees, and errors. Ensure DApps and smart contracts functionalities are intact, and accelerate development by fixing identified bugs before deployment. Verify inputs, outputs, and transaction structure to guarantee optimal performance.
Request Additional Blockchains For Your Transaction Simulator
The simulator is live for Ethereum, on mainnet and Sepolia. Need it on another blockchain? Tell us which one.
Frequently Asked Questions
Does the transaction-simulator API support Solana?
No. The simulator is EVM-only, so Solana transactions cannot be simulated through it. Only EVM-based networks (mainnet and testnet) are supported. If you need another network, the page provides a 'Request additional blockchains' option.
Can I estimate gas and catch transaction reverts before broadcasting?
Yes. Simulating an EVM transaction lets you preview its behavior, estimate gas usage, and detect failures or reverts before it ever hits the chain. This helps you optimize gas fees and prevent costly out-of-gas or reverted transactions. It runs against realistic mainnet state without spending real funds.
How does the simulator fit with preparing and broadcasting a transaction?
The simulator works alongside CryptoAPIs' Prepare Transactions and Blockchain Fees products for EVM chains. A typical flow is to prepare an EVM transaction, simulate it to confirm expected behavior and fees, then broadcast the signed transaction. This lets you validate inputs, outputs, and structure before going on-chain.
Is the Transaction Simulator available today?
Yes. The Transaction Simulator is live in the Blockchain API: simulate an Ethereum transaction on mainnet or Sepolia before you broadcast it, and see whether it succeeds or reverts, the gas it uses and the fee. You can request other blockchains from the page.
Simulate before you send
14-day free trial, mainnet included. No card needed.