Over 95% of all the bitcoin that will ever exist has already been mined. Of the 21 million coin cap, about 20.1 million coins are now in the world. The remaining supply arrives on a fixed schedule that slows every four years, and the next slowdown — the fifth halving — is due around April 2028.

OpenBitcoin.com, a bitcoin-only blockchain explorer and reference site, is tracking that event with a live countdown placed beside the lookups bitcoin users perform daily: a one-box search for any address, transaction or block, a price converter in 15 currencies, a fee tracker, and more than fifty guides, calculators and tools.

What the 2028 halving means

Every 210,000 blocks — roughly once every four years, since new blocks arrive about every ten minutes on average, though actual times vary — the number of new bitcoin issued with each block is cut in half. Those coins are paid out as the block subsidy to miners, which started at 50 per block at the network's launch in 2009 and has been halved four times since, in 2012, 2016, 2020 and 2024. The reward currently stands at 3.125 coins per block, or about 450 new coins a day. At block 1,050,000, expected around April 2028, it drops to 1.5625 coins per block, or about 225 a day. Nothing changes for coins already held; only the flow of newly issued ones slows.

A rounder milestone comes first: block 1,000,000, expected around April 2027, more than 18 years after the genesis block — the very first on the chain — was mined in January 2009. OpenBitcoin keeps a live countdown to that block at openbitcoin.com/block-1m, alongside a second countdown to the halving itself. After 2028, the halvings continue until the last fraction of a coin is mined around the year 2140.

Look anything up in one box

A bitcoin address, transaction ID or block number pasted into the search box on the front page returns the answer on a single page: balance and history for an address, inputs, outputs and fee for a transaction, and every transaction in a block. No account is required, nothing needs to be installed, and no altcoins are covered.

The price in your currency

The converter switches any amount between bitcoin, sats and 15 currencies, updating as you type. Sats, short for satoshis, are bitcoin's smallest unit — one hundred millionth of a coin. A price calendar covers every day since 2010, a cost-basis tool finds the price on any past date, and two calculators answer the classic questions: what a recurring buy would have produced, and what a purchase made back then would be worth today.

Fees without the guesswork

Bitcoin transaction fees move with demand for block space. The fee tracker shows what it costs to send right now, when fees are usually at their cheapest, and how large a transaction will be before it is broadcast.

Guides, research and tools

Nineteen guides cover both the basics and the common traps: what bitcoin is, seed phrase backup, self-custody, the most frequent scams and how to avoid them, address poisoning, Lightning, UTXOs, privacy and inheritance planning. Alongside them are tax guides for the United States and Canada, a history section on early bitcoin, a timeline of exchange hacks, a weekly census of reachable nodes, a fear and greed index with a year of history, and a look at the quantum computing question.

Eleven tools run in the browser, several of them fully offline: a seed-word checker, an address validator that points to the typo, a QR code generator, transaction and Lightning invoice decoders, a signed-message verifier, a mining calculator and an offline two-factor authenticator.

And three arcade games

Three arcade games — Block Builder, Backlog Breaker and The Impossible Slot Machine — turn live network data into play: stacking pending transactions into a block, breaking through a wall of fees, or trying to match a real bitcoin address at odds of one in 2 to the power of 160.

"Most bitcoin sites make you choose between a serious explorer and a site that explains things," the OpenBitcoin team said. "We wanted one place where you can check an address, see the price in your own currency, understand what a halving does, and get on with your day. Bitcoin only, no accounts, no noise."

Every figure shown on the site comes from its own full node, and the data layer is open source — a setup that lets the same numbers be reproduced independently from any bitcoin full node. The site is available at openbitcoin.com.

About OpenBitcoin

OpenBitcoin.com is an independent, bitcoin-only explorer, data and education site. It offers no trading, custody or investment advice. Contact: inbox@openbitcoin.com.

Source: Cryptopolitan