BrowserCoin (BRC) is a fully decentralized cryptocurrency that runs entirely in a browser tab.
Before anything else: there is nothing for sale here. No ICO, no presale, no premine, no token sale, no exchange listing, and no market of any kind. You cannot buy BRC, and I am not selling anything. The only way coins come into existence is by mining them.
This project is about having fun with technology, open-source and designed to make real participation in a crypto network as easy as it could be. Open a page, and you're a node. Have fun, learn something.
Website: https://browsercoin.org/Source (MIT): https://github.com/swompythesecond/BrowserCoinReddit: https://www.reddit.com/r/browserCoin/Discord: https://discord.gg/xV3De6ErTrWhy this existsMost people who "use crypto" today never touch the actual technology. They see a chart, and every interaction goes through a third party. Being a real participant in Bitcoin now requires ASICs. In 2009 it didn't: people ran a client on a normal PC, found blocks, and were there because the experiment was interesting. BrowserCoin tries to recreate that experience. Open a webpage and you are a full node: it syncs and verifies the chain, connects to peers over WebRTC, and can mine. No login, no signup, no special hardware.
Specifications- Ticker: BRC
- Total supply: 21,000,000 (hard cap)
- Block reward: 50 BRC, halving every 210,000 blocks (~1 year at target pace)
- Block time: 2.5 minutes
- PoW: Argon2id (memory-hard, 32 MB / 1 iteration), CPU mining in the browser, hostile to GPUs/ASICs
- Difficulty: ASERT retargeting every block (half-life 10 min), hard floor at genesis difficulty
- Ledger: account model (balance + nonce), Ed25519 signatures, bigint money everywhere
- Block size: 256 KB cap, per-byte minimum fee
- Premine: 0. Founder allocation: 0. Dev tax: 0.
Yes, the monetary policy is deliberately Bitcoin-shaped. It's well understood, the math is known, and it makes the chain instantly legible. The only intentional difference is the 4x faster block time, so a browser experiment feels alive.
Why Argon2id instead of SHA-256On SHA-256, a $2,500 ASIC has roughly 20 million times the hashrate of a normal PC, which would be fatal for a network meant to be mined in a browser tab. Argon2id is memory-hard: every hash needs 32 MB of RAM and the bottleneck is memory bandwidth, not compute, which GPUs and custom hardware can't scale per-core the way they scale SHA-256. The gap between a $20k server and a $400 laptop stays small enough that everyone has a realistic shot at finding blocks on whatever they already own, including phones.
How decentralized is it really?This is the part I care most about, so to be precise:
- No central authority signs blocks. No multisig of insiders. No "DAO". No checkpoint server that can rewrite or freeze history.
- The helper servers (one brokers the initial WebRTC handshake, one keeps a backup of the chain so a fresh tab can sync) are purely informational. They cannot sign blocks, override consensus, or mint coins. If mine go offline, the network survives.
- Helpers are now discovered dynamically: anyone can run one (npm run server:api / server:peerjs) and advertise it, no approval needed, and clients find them automatically. The Settings panel shows discovered helpers and lets you add your own. Helpers remain bootstrap hints only; your browser still validates every block locally, so a malicious helper can't forge anything or touch your coins. The official seeds stay as an anchor so nobody gets cut off.
- 51% defense is the same one Bitcoin actually relies on: cost. Memory-hard PoW raises per-hash cost, per-block ASERT retargeting closes the cheap-attack paths (with a two-interval emergency-drop rule so a single miner can't farm a difficulty discount), and network scale does the rest. No trusted-checkpoint shortcut, because that would defeat the point.
How to participate1. Open
https://browsercoin.org/ and a wallet is generated locally in your browser on first visit (back it up in Settings). The tab syncs and verifies the chain.
2. Click Mine. Your CPU starts grinding Argon2id hashes; land one under the target and you've found a block, worth 50 BRC.
3. To receive coins, show someone the QR next to your address or share your public key.
Community projectsIndependent projects people have built around the chain. Not affiliated with the core client, use at your own discretion:
I didn't build any of these, which honestly is my favorite thing that has happened with this project. Want to share something you built, or just hang out? Join us on Reddit (
https://www.reddit.com/r/browserCoin/) or Discord (
https://discord.gg/xV3De6ErTr).
Anticipated questionsIs this a scam / when exchange?There is no market and nothing I could sell you. If you want BRC, mine it or get someone to send you some. If a number-go-up chart is what you're after, this isn't for you.
Isn't browser mining what those cryptojacking scripts did?Same primitive, opposite consent model. Nothing mines unless you press the Mine button, it's your own wallet receiving the reward, and the code is MIT-licensed and small enough to actually read.
What happens if your servers die?Peers keep relaying blocks over WebRTC, and clients automatically discover community-run helper servers (anyone can run and advertise one, no approval needed). Anyone can also host the static page itself. The official seeds are just defaults.
Why an account model instead of UTXO?Smaller state, simpler to hold in a browser's memory. The privacy tradeoff vs UTXO is acceptable for an experiment with no fiat market.
Code, consensus rules, and tests:
https://github.com/swompythesecond/BrowserCoin (small enough to read in an afternoon). Feedback, code review, and attempted attacks on the testchain are all welcome. That's what the experiment is for.
