Yes. Like every FreeBTC game it costs nothing and you never stake anything. Good results add season points; season leaders share pots funded by the site.

Am I mining real bitcoin?

You do real proof of work on a real block header, but your merkle root is changed so the work is unique to you, and real blocks need far more zeros. It is a faithful lesson, not a way to earn block rewards.

Will it drain my battery?

Only while you hold the button, for 60 seconds at most per session, and never in a background tab. It uses a few CPU threads, like a demanding web game.

How far am I from a real block?

The game shows it live: from your hashrate it estimates how many years your device would need to find one valid block at today’s difficulty.

Bitcoin Mining Game — Mine a Real Block in Your Browser

How to play

Hold “Mine” to hash. Mining stops when you let go, when you switch tabs, and after 60 seconds per session; hold again to keep going.
Your score is the number of leading zero bits of your best hash, with decimals: 256 − log₂(hash + 1). Each new best is checked by the server, which recomputes the hash itself.
Season points: 22+ bits → 1 point, 26+ bits → 2 points, 30+ bits → 3 points. Ties go to whoever finished faster.
Tap “Finish & score” when you are happy. There are 4,294,967,296 nonces to try; up to 200 submissions per run.
One run per day. Every player hashes a different header, so nonces cannot be shared or copied.

About this game

This is not an animation: your browser really mines. You get the 80-byte header of a recent Bitcoin block, with a merkle root unique to you, and your device runs double SHA-256 over it millions of times per second, changing the nonce each time — exactly what mining hardware does.

Real blocks need a hash with around 79 leading zero bits. You will not get there (no browser can), but the hunt shows why: every extra zero bit doubles the work. Your best hash of the day is your score.