Free · No signup · Runs in the browser
A Bitcoin block clock for the screen you are not using
Block height, price, mempool fees, hash rate and the countdown to the next halving, laid out on one split-flap board that refreshes itself. Point a spare laptop or tablet at it and leave it running.
- ReadsBlock height
- ReadsBTC / USD
- ReadsMempool fees
- ReadsHalving countdown
Four screens, one board
The clock opens on the split-flap view and stays there until you ask for something else. The other three go deeper without ever leaving the same frame.
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Clock
The wall display
One number, very large, on a split-flap board — block height by default, or price, hash rate or blocks-to-halving if you prefer. Readable from across a room.
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Overview
Price, block and mempool together
BTC/USD with the seven-day change, the current block and how long since the last one, the block reward, halving progress, and a live feed of unconfirmed transactions as they arrive.
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Network
State of the chain
Hash rate, mining difficulty and when it next adjusts, mempool size in megabytes, circulating supply against the 21 million cap, and the most recent blocks.
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Halving
The supply curve
Blocks remaining, the estimated date, what the reward drops to, and the full history of every halving so far next to the ones still ahead.
What each number means
Every figure on the board is a live reading from the Bitcoin network, not an estimate or a delayed quote. Here is what each one is actually telling you.
| Reading | What it means |
|---|---|
| Block height | How many blocks have been added to the chain since the first one in 2009. It goes up by one roughly every ten minutes, and it is the closest thing Bitcoin has to a clock of its own. |
| Time since last block | How long the network has gone without sealing a block. Ten minutes is the target, but any single gap can be far shorter or longer — it is a probability, not a schedule. |
| Mempool | Transactions that have been broadcast but not yet included in a block. A crowded mempool is why fees rise: block space is fixed, so senders bid for it. |
| Fees in sat/vB | What it currently costs to get a transaction confirmed at low, medium and high priority, priced per virtual byte rather than per coin sent. |
| Hash rate | How much computing power is defending the chain, in exahashes per second. The higher it goes, the more expensive an attack on the network becomes. |
| Difficulty | How hard the mining puzzle currently is. It re-adjusts every 2,016 blocks so that blocks keep arriving about every ten minutes no matter how much hash rate joins or leaves. |
| Circulating supply | How many of the 21 million bitcoin that will ever exist have been mined so far. |
| Halving countdown | Blocks remaining until the block reward is cut in half, which happens every 210,000 blocks — about every four years. |
On the ten-minute rule: ten minutes is an average the difficulty adjustment aims for, not a promise about the next block. Seeing three blocks in four minutes and then nothing for half an hour is normal, not a fault in the readout.
If any of those readings are new to you, the explainer walks a single payment from a wallet to a settled block, one step at a time.
Every Bitcoin halving so far — and the next one
A halving cuts the new-coin reward per block in half, every 210,000 blocks — roughly every four years. These are the ones that have happened, as plain history:
| Halving | Date | Block height | Reward change |
|---|---|---|---|
| First | 28 November 2012 | 210,000 | 50 → 25 BTC |
| Second | 9 July 2016 | 420,000 | 25 → 12.5 BTC |
| Third | 11 May 2020 | 630,000 | 12.5 → 6.25 BTC |
| Fourth | 20 April 2024 | 840,000 | 6.25 → 3.125 BTC |
| Fifth (next) | expected around April 2028 | 1,050,000 | 3.125 → 1.5625 BTC |
Price ran up in the months after each of the first three halvings; whether that is cause or coincidence is argued about endlessly. The clock does not take a side — it counts blocks, and the halving view shows the live countdown to 1,050,000.
No account, no server in the middle
BlockClock reads public Bitcoin APIs straight from your browser. There is no backend of ours between you and the data, which means there is nothing for us to log, no account to create and nothing to install — no extension, no app store, no desktop client.
It also means the page is honest about its own limits. If an upstream API is slow, the board says so rather than showing a stale number as if it were fresh.
You can change how it looks — light or dark, denser or roomier spacing, motion on or off — and the choice is remembered on your own device rather than tied to a profile somewhere.
Weighing this against a dedicated hardware display instead? Here is an honest comparison of what each one is actually good at.
Common questions
Is BlockClock free?
Yes. Open the link and it runs. There is no account, no trial and no paywall on the numbers.
Where does the data come from?
Public Bitcoin APIs, read straight from your browser. Nothing is proxied through a server in the middle, so what you see is what those APIs return.
Can I leave it running on a spare monitor?
That is what the clock view is built for. It fills the screen with a split-flap readout and keeps refreshing on its own, so an old laptop or tablet becomes a wall display.
Do I need an account or a wallet?
Neither. BlockClock only reads public network data. It never asks for a wallet, a key, an email or a password, because it has nothing to connect them to.
When is the next Bitcoin halving?
Halvings happen every 210,000 blocks, roughly every four years. The halving view shows how many blocks are left, the estimated date, and what the block reward drops to.
What is the current Bitcoin block height?
It rises every ten minutes on average, which is why a static page cannot tell you — the clock reads it live from public APIs. As fixed reference points: 840,000 at the April 2024 halving, 1,050,000 at the next.
Is it available in Thai?
Yes. The whole interface reads in Thai as well as English, with crypto terms such as block, halving and hash rate left in English the way Thai readers actually use them.
Put it on a screen
Nothing to install, nothing to sign up for. Open it and walk away.