About the project
ONLY21 is The 21 Data Lab: Bitcoin calculators, live network data and statistics from our own price database since 2010. It is EUR-native, cookieless and free of paywalls; statistics and indicators are computed deterministically from that data.
What you find here
Live dashboard & network
In real time: price, block height, hashrate, mempool and fees.
Calculators
DCA, what-if, BTC/sats/EUR/USD converter and a fee calculator.
Our own statistics
Technical analysis, cycles & signals (RSI bottom, seasonality, power-law), purchasing power of dollar and Bitcoin, price history since 2010, volatility clock.
EUR-native & cookieless
Euro as a first-class currency, no cookies, no paywalls, no ads.
Data & methodology
The Bitcoin price comes from the exchange Coinbase and the aggregator CoinGecko but is fully stored on our side: over 1.5M records at 5-minute resolution since 2012, plus daily data from 2010. Network data comes from our own node; inflation and gold are external reference. Every source and its cadence is documented under "About the data", and how each metric is computed under "Methodology".
Privacy & transparency
01Cookieless
No cookies, no cross-device tracking. Language/currency choice lives in localStorage only.
02No personal data
We store no personal information about visitors.
03Self-hosted analytics
Anonymous stats via Anonyze on our own servers. No Google Analytics, no cross-device tracking.
04No ads, no data sales
No advertising, no selling of user data.
05Hosting in Europe
GDPR-compliant, data processing in the EU.
Who runs this
ONLY21 is operated and maintained by a single person. The imprint names that person openly, with a full address. Questions or corrections are welcome at hello [at] only21.net.