Strike a Block: Write Yourself into a Genesis Block
The original
It began with a headline.
The Times03 · Jan · 2009
Chancellor on brink of second bailout for banks
Billions may be needed as lending squeeze tightens. The Chancellor<br>will decide within weeks whether to pump billions more into the<br>economy as evidence mounts that the £37 billion part-nationalisation<br>has failed to keep credit flowing.
This exact headline is embedded, byte for byte, in<br>Bitcoin's first block: a timestamp, and perhaps a comment, that will<br>outlive the paper it was printed on.
On 3 January 2009, someone using the name Satoshi Nakamoto mined<br>block 0 , the genesis block, and inscribed that day's Times<br>headline into it. Every one of the billion-plus Bitcoin transactions<br>since traces its ancestry to this one block.
The block below is the real thing: its actual hash,<br>nonce, and inscription, exactly as they sit at the root of the chain<br>today.
“The Times 03/Jan/2009 Chancellor on brink of second bailout for banks”
000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f
nonce 2,083,236,893<br>3 Jan 2009, 18:15 UTC<br>struck by: one CPU, somewhere
Plain terms
Three ideas, no jargon.
A genesis block is simpler than it sounds. It's made of<br>three things you already understand, or<br>take the 5-minute interactive lesson and learn it<br>by breaking one.
[ page one ]
The first page of a ledger
A blockchain is a book of records where each page references the page<br>before it. The genesis block is page one, the only page with nothing<br>before it. Its “previous page” field is just zeros:<br>000…000. Every chain, including Bitcoin, has exactly one.
[ the inscription ]
Words carved in, forever
The miner of a block gets to include a short message. Change a single<br>letter of it, and the block's fingerprint (its hash) changes<br>completely, breaking every page that follows. That's why Satoshi's<br>headline can never be quietly edited. Inscriptions are permanent.
[ the proof ]
Work you can verify at a glance
Mining means retrying the block with different “nonce” numbers until<br>its hash starts with enough zeros. Finding one takes billions of tries;<br>checking one takes an instant. The zeros at the front of a block hash<br>are the receipt for the work.
Then & now
What took a CPU its evenings takes silicon a blink.
A block at Bitcoin's original difficulty needs about<br>4.3 billion hash attempts on average. Here's what that costs, by machine:
MachineHash rateOne genesis-difficulty block, on average
2009 desktop CPU (what Satoshi used)<br>~2–4 MH/s<br>~20–35 minutes of steady hashing
Your browser, this page (JavaScript)<br>~0.5 MH/s<br>~2½ hours
One USB stick miner, 2026 (BM1397 ASIC, 672 cores)<br>~200 GH/s<br>21 milliseconds, about 47 blocks per second
The demo below uses a friendlier target (a hash<br>starting with four zeros, about 65,000 attempts) so your browser can<br>strike a block in around a second. Same mechanism, smaller mountain.<br>(Curious about block 0 itself? The six-day gap between it and block 1<br>remains one of Bitcoin's small mysteries.)
Your turn
Strike a block with your own words.
Type an inscription. Your browser will hash it with a<br>timestamp and a counting nonce (double SHA-256, the same algorithm as<br>Bitcoin) until the hash starts with the zeros you asked for. Nothing<br>leaves this page.
Strike it
Target<br>000… (~4,000 tries)<br>0000… (~65,000 tries)<br>00000… (~1M tries)
The forge is idle. Type an inscription and strike.
The vault
Recently struck on real silicon.
Blocks below were mined not by a browser but by a<br>GekkoScience Compac F, a thumb-sized ASIC with 672 hash cores, at<br>Bitcoin's original genesis difficulty. Full 32-zero-bit proof of work,<br>the same bar Satoshi's block cleared.
“Compac F Genesis”
000000002bfdd443b79ac22e8abc216d1c055598fb581c42113d8e6c0f69afec
nonce 627,715,779<br>15 Jul 2026<br>difficulty: same as Bitcoin block 0
Your inscription could be next.
00000000····························································
awaiting the forge
The vault is public and anonymous. Inscriptions<br>appear without any information about who requested them. The six most<br>recent strikes show here; browse the complete<br>archive →
Two ways to strike
Free in your browser, or real on silicon.
Play with the idea for nothing, or have a genuine<br>genesis-difficulty block struck on the ASIC, the same difficulty as<br>Bitcoin's block 0, with a certificate anyone can verify.
Free · in your browser
Free
Mine a toy block yourself, right on this page
Choose the difficulty: 000, 0000, or 00000
Instant, and it runs entirely on your machine
No account, nothing stored, nothing to pay
Mine in your browser →<br>A learning toy at a much lower difficulty than the real thing.
Real Genesis Strike
Free while in beta
A real block at Bitcoin's original genesis difficulty
Struck on ASIC silicon with your inscription
Added to the public vault, anonymously
Up to 10 per account, just sign in
Sign in & mine for free<br>No payment while we're in beta.<br>Sign in, write your line, and watch...