Does it store the raw transaction data literally like (excuse the formatting inaccuracies):

0x24134i59435ej3...9 sends 0x9wri03vw3sdfsd...i 26.00000023423 Bitcoin.

Or is it stored differently?

1 Answer 1


Bitcoin core stores the data in the network format for blocks and for the transactions in those blocks.

Here's an example

Block 170 contains the first transaction other than coinbase transactions. In it Satoshi Nakamoto paid Hal Finney 10 BTC. This was the first time one person paid another person in Bitcoin.

Since the data is in binary, we must use a printable representation of it to make it viewable in this web-page. I choose hexadecimal:


Some weeks ago I thought it would be neat to work out by hand what that meant. here's how far I got before losing interest:

Hex Data Meaning
01000000 Version 1 (little endian uint32)
01 Number of transaction inputs (compact-int)
First input
c997a5e56e104102 fa209c6a852dd906 60a20b2d9c352423 edce25857fcd3704 Hash of referenced transaction (32 octets)
00000000 index of output in referenced transaction (uint32)
48 length of unlocking script (compact-int). 48 hex is 72 decimal.
47304402204e45e1 6932b8af514961a1 d3a1a25fdf3f4f77 32e9d624c6c61548 ab5fb8cd41022018 1522ec8eca07de48 60a4acdd12909d83 1cc56cbbac462208 2221a8768d1d0901 unlocking script (72 octets)
ffffffff sequence
02 Number of outputs
First output
00ca9a3b00000000 amount 1000000000 satoshi i.e. 10 BTC (int64)
43 length of locking script
4104ae1a62fe09c5 f51b13905f07f06b 99a2f7159b2225f3 74cd378d71302fa2 8414e7aab37397f5 54a7df5f142c21c1 b7303b8a0626f1ba ded5c72a704f7e6c d84cac locking script
Second output
00286bee00000000 amount 40 BTC. This is change.
43 length of locking script
410411db93e1dcdb 8a016b49840f8c53 bc1eb68a382e97b1 482ecad7b148a690 9a5cb2e0eaddfb84 ccf9744464f82e16 0bfa9b8b64f9d4c0 3f999b8643f656b4 12a3ac locking script
00000000 lock time = unlocked (4 octets)

I should probably decode the locking scripts on the outputs. 41 is OP_PUSHDATA for 4116 bytes. Then we have the 4116 bytes of data to be pushed onto the stack and finally ac is OP_CHECKSIG which expects a signature and public key on the stack which it takes off the stack and checks. This script only really gets executed when the money is spent.

For historical reasons locking-scripts were called pubkey scripts, unlocking scripts were called signature scripts. But those older names are misleading for newer transaction types.

The compact form of integers used by Bitcoin is sometimes called varint (variable-length integer) but this is a potential source of confusion as there are other things named varint IIRC.

You can check the little endian numbers by reversing them byte-wise (two hex digits at a time) into a big endian representation and feeding that into Windows Calculator in programmer mode - here's that second output amount (00286bee00000000LE -> 00000000ee6b2800BE):


That's how we know 00286bee00000000 means 40000000000 Satoshi. Which is 40 BTC.

This early transaction is an early type known as Pay to Public Key (P2PK). It is the simplest type. Popular types used nowadays are more complicated.

You can, of course, rather easily get a JSON representation of this transaction using most blockchain explorers. I find that a bit unsatisfactory as they often introduce some artificial elements (e.g. both 'hex' and 'asm' representations of the script) so you're never certain how exactly the JSON items correspond to parts of the underlying data. Hence the above decoding attempt.

Related questions


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.