Op Codes

OP Codes Are The Building Blocks Of Script

Short for operation codes, these are the building blocks of Bitcoin Script, the scripting language used in the Bitcoin protocol. Each op_code represents a specific operation/function/command that manipulates or reads data within a Bitcoin Script. Explore a few below!

OP_ZERONOTEQUAL

Checks if the top item of the stack is not 0

Math

Pop & Push

OP_1ADD

Increments the top item of the stack by 1

Math

Pop & Push

OP_1SUB

Decrements the top item of the stack by 1

Math

Pop & Push

OP_ABS

Absolute value of the top item of the stack

Math

Pop & Push

OP_ADD

Adds the top two items on the stack and pushes the result onto the stack.

Math

Pop & Push

OP_BOOLAND

Logical AND of the top two items of the stack

Math

Pop & Push

OP_BOOLOR

Logical OR of the top two items of the stack

Math

Pop & Push

OP_CHECKLOCKTIMEVERIFY

Ensure a UTXO cannot be spent until an absolute block height or specific time

Locktime

Push

OP_CHECKSEQUENCEVERIFY

Ensure a UTXO remains unspendable for a relative number of blocks or duration since its confirmation.

Locktime

Verify

OP_CHECKMULTISIG

Verifies multiple signatures against multiple public keys.

Crypto

Pop & Push

OP_CHECKSIG

Verifies a cryptographic signature against a public key & a message.

Crypto

Pop & Push

OP_DEPTH

Pushes the depth of the stack onto the stack.

Stack

Stack

OP_DROP

Removes the top item from the stack.

Stack

Pop

OP_DUP

Duplicates the top item on the stack and pushes the duplicate onto the stack.

Stack

Push

OP_EQUAL

Checks top items for equivalency & pushes result (0x00 or 0x01)

Logic

ScriptControl

OP_EQUALVERIFY

Compares the top two items on the stack for equality, doesn't push result.

Logic

Conditional

OP_GREATERTHAN

Returns 0x01 if item-1 is greater than item-2, 0x00 otherwise

Math

Pop & Push

OP_GREATERTHANOREQUAL

Returns 1 if item-1 is greater than or equal to item-2, 0 otherwise

Math

Pop & Push

OP_HASH160

Hashes the top item on the stack using the SHA-256 & RIPEMD-160 algorithms.

Crypto

Pop & Push

OP_HASH256

Applies the SHA-256 hashing algorithm twice on the top item of the stack.

Crypto

Pop & Push

OP_LESSTHAN

Returns 0x01 if item-1 is less than item-2, 0x00 otherwise

Math

Pop & Push

OP_LESSTHANOREQUAL

Returns 1 if item-1 is less than or equal to item-2, 0 otherwise

Math

Pop & Push

OP_MAX

Pushes the larger of the top two items on the stack onto the stack.

Math

Pop & Push

OP_MIN

Pushes the smaller of the top two items on the stack onto the stack.

Math

Pop & Push

OP_NEGATE

Negates the top item of the stack

Math

Pop & Push

OP_NIP

Removes the second-to-top stack item.

Stack

Pop & Push

OP_NOT

Logical NOT of the top item of the stack

Math

Pop & Push

OP_NUMEQUAL

Compares the top two items of the stack for equality

Math

Pop & Push

OP_NUMEQUALVERIFY

Compares the top two items of the stack for equality, stops executing if false

Math

Pop & Push

OP_NUMNOTEQUAL

Compares the top two items of the stack for inequality

Math

Pop & Push

OP_OVER

Copies the second-to-top stack item to the top.

Stack

Pop & Push

OP_PUSHDATA

Pushes arbitrary data onto the stack

Data

Push

OP_RETURN

Marks the transaction as invalid and returns all of the remaining bytes as an error message.

Flow Control

ScriptControl

OP_RIPEMD_160

Input is hashed using the ripemd160 hashing algorithim

Crypto

Pop & Push

OP_SHA1

Performs the SHA-1 hash function on the top item of the stack.

Crypto

Pop & Push

OP_SHA256

Input is hashed using the sha256 hashing algorithim

Crypto

Pop & Push

OP_SIZE

Pushes the size of the top item on the stack onto the stack.

Stack

Push

OP_SUB

Subtracts the second item from the top item of the stack

Math

Pop & Push

OP_SWAP

Swaps the top two stack items.

Stack

Pop & Push

OP_WITHIN

Checks if the third item of the stack is within the top two items.

Math

Conditional

OP_CHECK_SIG_ADD

Verifies a signature against a public key and increments the result by one if successful.

Crypto

Pop & Push

OP_2SWAP

Swaps the top two stack items.

Crypto

Pop & Push

OP_TOALTSTACK

Moves the top item from the main stack to the alternate stack.

Stack

Pop & Push

OP_FROMALTSTACK

Moves the top item from the alternate stack to the main stack.

Stack

Pop & Push

OP_2DROP

Removes the top two items from the stack.

Stack

Pop

OP_ROT

Rotates the top three items on the stack.

Stack

Pop & Push

OP_TUCK

Duplicates the top stack item and inserts the duplicate copy before the second-to-top item.

Stack

Pop & Push

OP_ROLL

Moves the nth item from the stack to the top position.

Stack

Pop & Push

OP_PICK

Duplicates the nth item from the top of the stack and pushes it onto the top of the stack.

Stack

Pop & Push

OP_INVERT

Performs a bitwise inversion on the top item of the stack.

Arithmetic

Pop & Push

OP_AND

Performs a bitwise AND operation between the top two items on the stack.

Arithmetic

Pop & Push

OP_OR

Performs a bitwise OR operation between the top two items on the stack.

Arithmetic

Pop & Push

OP_XOR

Performs a bitwise XOR operation between the top two items on the stack.

Arithmetic

Pop & Push

OP_MUL

Performs a multiplication operation between the top two items on the stack.

Arithmetic

Pop & Push

OP_2MUL

Multiplies the top item on the stack by 2.

Arithmetic

Pop & Push

OP_2DIV

Divides the top item on the stack by 2.

Arithmetic

Pop & Push

OP_DIV

Performs a division operation between the top two items on the stack.

Arithmetic

Pop & Push

OP_MOD

Performs a modulo operation between the top two items on the stack.

Arithmetic

Pop & Push

OP_LSHIFT

Performs a bitwise left shift operation on the top two items on the stack.

Arithmetic

Pop & Push

OP_RSHIFT

Performs a bitwise right shift operation on the top two items on the stack.

Arithmetic

Pop & Push