BTC21 knowledge base
Public Electrum Server FAQ
Connection and safety answers for BTC21’s free public Electrum service. Your wallet and keys stay under your control.
What is a public Electrum server?
An Electrum server indexes Bitcoin blockchain information and lets Electrum wallets query balances, transaction history, and transaction status without operating a full wallet server themselves.
Is the BTC21 Electrum service free?
Yes. BTC21 provides public Electrum access as free community infrastructure. No subscription or payment is required.
How do I connect Electrum to BTC21?
Open Electrum’s server settings, choose manual server selection, and enter the current BTC21 hostname, port, and protocol shown on the connection page. Follow the published Tor instructions if using an onion service.
Does BTC21 hold my Bitcoin?
No. BTC21 is non-custodial. Your wallet and private keys remain under your control, and BTC21 does not hold user funds.
Should I enter my seed phrase on this website?
Never. Do not enter a seed phrase, private key, wallet password, or recovery file into the BTC21 website or any server connection form. Configure the server inside the Electrum application.
Can I use Electrum with Tor?
Yes, when your Electrum installation and network configuration support Tor. Use only the current official BTC21 onion hostname and connection details published on the site.
What if Electrum cannot connect?
Check the hostname, port, protocol, SSL setting, Tor availability, system clock, and Electrum version. Try the documented clearnet or Tor endpoint and verify that your firewall permits the connection.
What privacy information does an Electrum server receive?
An Electrum server can see the requests needed to answer your wallet, and a public server may be able to associate queried addresses. Electrum explains these tradeoffs in its official FAQ. Using Tor can improve network privacy, but a single-server setup involves tradeoffs; read Electrum's Tor guidance before changing settings.
Which wallets and resources are relevant?
BTC21 does not endorse or distribute wallet software. Electrum is the reference client for this protocol. Sparrow Wallet documentation describes connecting through a public server, Bitcoin Core, or a private Electrum server; the BlueWallet documentation is a separate mobile-wallet resource. Get software only from official project sites and verify downloads where possible.
How do I connect safely?
Use the server settings inside your wallet application, verify the hostname and TLS details presented there, and keep your wallet recovery phrase, private keys, password, and wallet file private. An Electrum server is not a website login and will never need those secrets. Electrum documents its server trust and TLS model in detail.