The new standard
Transact with confidence. Preview how transactions will behave on-chain, and keep your assets safe.


Empower your users to transact with confidence
Actionable simulations
In 2022, more than $5B was lost in crypto scams. With transparent previews, Transaction Simulation ensures transactions will behave as users expect.
Save gas
Simulate a transaction and know if it will revert on chain ahead of time. No more wasting unnecessary gas.
Control your data
With three products, Asset Changes, Execution Simulation and Bundle Simulation, choose the type of transaction to simulate, and the format and granularity of the preview data.
Ergonomic access
Simulate any transaction with a single method. Compatible with the Alchemy SDK and available on Ethereum, Polygon, Arbitrum, Optimism and Base.
Educate your users
Malicious transactions are predicated on opaque smart contracts that most users don't understand. Users deserve predictability and clear previews, 100% of the time.
Complex inputs, simple outputs
Other simulation methods, e.g., debug_traceCall, have limited functionality with hard-to-parse outputs. Now, simulate complex transactions and get simple results, such as why transactions will fail and revert.
What you can do
Asset Changes
Receive simulation data that is sanitized and simplified, to quickly find out the asset deltas of a transaction, before it's executed.
Execution Simulation
Receive an end-to-end simulation of the EVM execution, inclusive of ABI decoded results and comprehensive logs, events and traces data.
Bundle Simulation
Pass in an array of transactions to accurately simulate and preview sequential transactions. Example use cases may be (1) simulating the end-to-end flow of approving before swapping a token or (2) deploying a contract then calling a function on that contract.
“Alchemy handled the heavy lifting for us and saved us hundreds of hours of development time. Transaction Simulation allowed us to go-to-market 4 weeks faster!”

tools for the transaction lifecycle
The Smart Transaction Platform
UserOp Simulation
UserOp Simulation APIs enable you to know how a UserOp will behave before it's executed.
Use with Transaction Simulation so users can preview both Externally Owned Accounts (EOA) and Smart Contract Account (SCA) transactions.
Reinforced Transactions
Reinforced transactions send transactions 7.9x faster and 100% reliably, no matter what.
Use with Transaction Simulation so users can preview transactions then send them fast and reliably.
Private Transactions
Use Flashbots' private relay to prevent frontrunning.
Use with Transaction Simulation so your users understand asset changes ahead of time, and then can protect their txn from malicious MEV until it's included on chain.
Alchemy Notify
Through advanced webhooks, get notified as transactions move through the mempool and land on chain.
Use with Transaction Simulation to understand how a transaction will behave ahead of time and get notified as soon as its mined.