Halving Countdown Screensaver
The Halving Countdown screensaver shows the blocks and estimated time until the next Bitcoin halving, from the live block height — the event that cuts the mining reward in half. From mempool.space, free, in your browser, and ESC exits.
How the Halving Countdown screensaver works
The saver reads the current Bitcoin block height live from the key-less mempool.space API.
It works out how many blocks remain until the next halving, which happens every 210,000 blocks.
At roughly ten minutes a block it estimates the date and shows a ticking countdown, plus the reward before and after.
It refreshes the height every minute, so the count creeps down as new blocks are mined.
A worked example
The board reads tens of thousands of blocks remaining to halving #5, a ticking estimate of ~2y 140d, and the reward dropping from 3.125 → 1.5625 BTC — the four-yearly squeeze that defines Bitcoin's supply.
Settings & tips
- Accent recolours the counter.
- Background sets the backdrop.
- The time is an estimate at roughly ten minutes per block.
Frequently asked questions
- Is the block height live?
- Yes. It comes from the mempool.space API and refreshes every minute, so the remaining-block count is current.
- What is the halving?
- Roughly every four years (210,000 blocks) Bitcoin's mining reward is cut in half — a built-in tightening of new supply.
- Why is the date an estimate?
- Blocks average about ten minutes but vary, so the date is projected from that average and shifts slightly over time.
- Does it need a key?
- No. The mempool.space API is free and key-less; the saver only needs an internet connection.
- Is it free?
- Yes — free, no download, in your browser.