The Lightning Network is a layer-2 network on top of Bitcoin that lets people send bitcoin payments through payment channels without waiting for block confirmations. Normally, only opening and closing a channel are recorded on the blockchain. It suits small, frequent payments, but you need a wallet that supports it.
How does the Lightning Network work?
Two people open a payment channel by locking bitcoin into a shared address with one on-chain transaction. They then pay each other by signing updated balances, without broadcasting each payment or waiting in the mempool. Either side can close the channel, which records the final balances on the blockchain.
Amounts are counted in satoshis and millisatoshis (thousandths of a sat), which suits tiny payments. The idea comes from a 2016 paper by Joseph Poon and Thaddeus Dryja.
Example: how does a payment hop between channels?
You do not need a channel with everyone you pay. Say Avron has a channel with Bernice, and Bernice has one with Chemel. Avron can pay Chemel through Bernice:
- Invoice. Chemel sends Avron an invoice locked to a secret only Chemel knows.
- Promises. Avron promises Bernice the amount if she reveals the secret before a deadline. Bernice makes Chemel the same promise with an earlier deadline.
- Settlement. Chemel reveals the secret to get paid, and Bernice uses it to collect from Avron. Bernice may earn a small routing fee but cannot keep the payment.
What are the trade-offs?
- Liquidity. You can send only your side of a channel’s balance, and receive only up to the other side’s (inbound capacity).
- Staying online. If the other party closes a channel with an old balance, you have limited time to challenge it. Offline wallets can use a watchtower, a service that watches for this.
- Routing failures. Senders cannot see balances inside other people’s channels, so payments, especially large ones, can fail and need a retry.
- Custody. Custodial Lightning wallets hold your funds, so you must trust the provider. Non-custodial wallets keep you in control, but you manage channels and backups.
- On-chain costs. Opening and closing channels are Bitcoin transactions that pay network fees and wait for confirmations.
Why does the Lightning Network matter when you buy crypto?
Lightning only works with wallets that support it. Crypto is delivered to the wallet address you provide, and a Lightning invoice (on Bitcoin it starts with “lnbc”) is not a regular bitcoin address. Check what the order form asks for. See how to place an order, or see the Bitcoin price and payment options.
What are the risks and red flags?
- Payments are final. Completed Lightning payments cannot be reversed, so check the amount and who issued the invoice.
- Backups differ. Some non-custodial wallets need a separate channel backup, not just the seed phrase, to restore channel funds.
- Fake helpers. Nobody needs your seed phrase to open a channel or unstick a payment. See how to protect yourself from fraud.
Go deeper: How does Bitcoin work?
