Contract verification allows smart contract developers to prove and publish the source code of the contracts deployed on-chain.

This in turn allows end users to inspect and independently verify that a particular contract function does exactly what it is intended to do by reading the contract source code.  

There are 3 different tiers of contract verification available when open sourcing contracts on Etherscan.  

Unverified

An unverified contract tab is the default for all contract addresses upon being deployed to the blockchain, showcasing the contract creation's bytecode.

As the contract creator, you may choose to verify your source code from which, if successful, will be updated to Exact Match.

Similar Match

You may search for similar contracts using our Similar Match Search tool!

A similar match verification happens automatically when your contract creation's bytecode matches an existing contract that has been deployed and verified on Etherscan.

This however does not take into account constructor arguments ( simply initial settings of a contract, or if you'd like to dive deeper ).  

The contract code tab displays a yellow verified badge, along with the contract address it was matched to.

Exact Match

Akin to Similar Match above, an Exact Match verification represents the exact contract code that was deployed, along with any constructor arguments that was deployed with it.

The contract code tab displays a green verified badge, complete source code and deployment details, as well as the ability to interact with it via our built-in Read/Write contract buttons.

Contract Verification FAQs

Can I unverify a contract ?

In general — no. Contracts that have been verified on Etherscan are considered to have been made open source.

Can Similar Match be upgraded to Exact Match ?

If your contract was verified via Similar Match, there is no tool to include constructor arguments to attain Exact Match for the time being — we're considering making this an option in the future!

Update 4/5/22: Similar Match reverification is now enabled for whitelisted users.