HOW MINING WORKS

Minting, in plain words

Every card stands for a real contract someone deployed on Ethereum in 2015. You earn one by spending the same proof of work it took to mine the block that contract arrived in.

How long will it take?

On an RTX 5090 (225 MH/s), about 2 to 12 hours per solution, depending on the card. Each card needs the difficulty of its own 2015 block, and later blocks were harder. Slower GPUs take proportionally longer, and a laptop browser can take months.

These are averages. Mining is luck: every attempt has the same small chance, so a solution can come in the first minutes or take several times longer. There is no progress towards it. The mining page shows the time for each card, and a measured estimate for your device once you start. Each level-up costs the same work again.

What does it cost?

Electricity to mine and gas to submit. There is no price and nothing to buy.

Can I pay less gas?

Today you hardly need to. Checking the whole proof of work on Ethereum takes about 1.8 million gas, and with gas near 0.2 gwei that is about 0.00036 ETH. Gas has been far higher before and may be again: at 20 gwei the same mint would cost about 0.036 ETH. For that case there is a second way to send a solution.

The second way is optional and uses a zk proof. Normally the transaction carries the pieces of the dataset your solution used, about 43 KB, and Ethereum checks the work itself. With the zk option, your own computer runs that check and sends a 356-byte proof that it passed instead, which cuts gas by about 80%: about 395,000 for a mint and 312,000 for a level-up. You get the same card, level and golden chance either way.

The proof takes real hardware: about 27 GB of RAM and about 5 minutes on a 16-core CPU per solution, plus a one-time 6.2 GB download. Succinct's prover network can make it for a fee instead. The browser mining page always sends the normal way, so the zk option is for people running their own miner. For a mint, the card is not reserved while the proof is made. The LLM instructions have the details.

What do I get?

The card for that contract, drawn and stored entirely on-chain. Its gem is frosted glass until you mint it, then turns the full colour of the month the contract was deployed. Each level after that adds a sparkle and a brighter glow, up to twelve. Cards count towards the sets on Collect, and your work counts on its Season 1 leaderboard. Collect also has two achievements: Get a golden, and Neighbors, for holding two cards with neighboring numbers such as #0100 and #0101. After your first card, the mining page links to the cards next to it.

What is my computer actually doing?

Trying numbers. It runs Ethash, the algorithm that secured Ethereum in 2015, on one number after another until the result falls below the card's target. Each try is an independent roll of the dice.

Every solution is checked in full on Ethereum before it counts, so nobody can cheat or claim an easier block.

Why does it download data and then build more?

Ethash reads from a dataset of about a gigabyte. Your browser downloads a small seed (around 18 MB), builds the full dataset from it on your GPU, checks it, and keeps it in browser storage when there is room. Building it takes seconds to minutes depending on the device.

The dataset is shared by cards from the same period, so the next card is often quicker to start. The mining page shows how much is stored and can clear it; clearing removes everything, including solutions you have not sent yet.

Why do I give an address before mining, not after?

The address is part of the puzzle. A mint solution only works for the address it was mined for, so nobody can take your solution and send the card to themselves. Any wallet can send it and pay the gas; the card still goes to that address.

Level-ups need no address: the work is tied to the card itself, and anyone can mine or send it.

A solution does not reserve a card. Someone else can still mint it before your transaction confirms.

Does the tab need to stay open?

Yes, open and visible. Hiding it (another tab, minimising the window, a locked screen) pauses mining, and it picks up again by itself when the tab is visible. It does not need to be the active window, and while it mines the page keeps the screen awake so the computer does not go to sleep. If the GPU resets or the miner stops, it restarts on its own. Nothing is lost by pausing, because every attempt is independent.

A solution you find is saved in this browser and comes back after a reload, ready to send. Download proof keeps a separate copy.

The mining page reports anonymous statistics to eth2015.com, to learn how people use it: which card was opened, when mining starts, stops and finds a solution, the speed, GPU model, work done and closest hash, and, when WebGPU fails or runs only in software, what went wrong with the browser's name and version, operating system and GPU adapter, so we can improve the setup steps. They are linked by a random ID kept in this browser's storage, so a later visit from the same browser can be recognised, and carry the country Cloudflare reports. No wallet address or IP address is stored.

Can I mine faster, outside the browser?

Yes, and on a big GPU a native miner is much faster. Ask your LLM to build one from the LLM instructions. It solves the same puzzle, and its solutions are checked exactly the same way.

Can I send a solution without this site?

Yes. Download proof on the mining page gives one file with the solution and everything needed to send it, for a wallet tool or your own miner. The Developer FAQ has the details. Any wallet can pay the gas.

How do levels work?

A card starts at level 1 when it is minted. Each different valid level-up solution adds one level, at the same difficulty every time.

Anyone can contribute, and work belongs to the card rather than to its owner: it stays valid if the card is sold or someone else raises it first. If two miners each find a solution while the card is at level 5, both count, and it goes to 7.

Every accepted solution is recorded, so the same one never counts twice. You can keep a solution and send it later, even after selling the card; the holder at that time gets the level.

What is a golden card?

A mint does not roll for golden. Every level-up of a card that is not golden has a 1 in 5 chance of turning it golden: a gold gem and frame, on-chain art and a Golden finish in its metadata. Once golden, always golden, and a golden card's level-ups add levels but roll nothing more. Golden cards have their own board on Collect.

You find out a few seconds after your level-up lands. A golden result then asks for one more transaction, Claim your golden, which makes it golden for good. There is about a day to claim it (8,191 blocks); after that it stays regular. If someone levels the card up first, that level-up claims it for the holder.

How can it be fair on a public chain?

Everything on a public chain can be read, so the roll uses something that does not exist yet when you send your transaction: the hash of the next block. The contract works out keccak256(next block hash, token) % 100 and a zero is golden. Nobody can see it in advance, not you, not us, and nobody can cancel a transaction after seeing it, because it is already in a block by then. The site shows the result from that block's hash; the contract checks the same thing again when you claim.

Is any of this a race I can lose?

Minting is: whoever mints a card first gets it, and a mint solution cannot be turned into a level-up.

Level-ups are not. Every different solution counts, whoever sends it first. Only an exact copy of a solution that has already been accepted is rejected.

More detail in the Developer FAQ, or the full specification in the LLM instructions. Back to the collection.