Transaction simulation runs a proposed blockchain action against a model of current state before the user signs or broadcasts it. A wallet may use the result to preview token movements, approvals, or contract calls.
Simulation can make hidden effects visible
A readable preview can reveal that a request transfers an unexpected token, grants a large allowance, or calls a suspicious contract. It gives the user more information than raw hexadecimal data alone.
Simulation estimates effects before authorization
The preview can decode expected transfers, approvals, logs, and contract calls so the user can compare them with the action they intended.
A safe-looking preview is not absolute proof
The real transaction may execute later under different state, and malicious contracts can attempt to behave differently during analysis. Users should still verify the site, contract, network, permissions, and destination.
Simulation is a safety signal, not a guarantee
State changes, unsupported behavior, provider blind spots, and adversarial contracts can make a preview incomplete or misleading.
Sources
Educational information, not investment advice.