Lightning Network
How to buy a coffee with Bitcoin
Bitcoin on-chain transactions are slow and expensive. The Lightning Network is a Layer 2 payment protocol built on Bitcoin, enabling sub-second payments with near-zero fees. We explore payment channel mechanics through to running your own Lightning node.
Why Does This Matter?
- 1
On-chain Bitcoin: ~10 min wait, fees in the thousands of won — unsuitable for small payments.
- 2
Lightning can process millions of transactions per second — faster than Visa/Mastercard.
- 3
In El Salvador, Argentina and elsewhere, Lightning Bitcoin payments are already used daily.
Key Concepts
An off-chain Bitcoin balance relationship between two parties. On-chain transactions only occur when opening/closing the channel; all payments in between are instant.
A cryptographic contract that routes payments safely through multiple nodes even without a direct channel.
A payment request. Expressed as a QR code or text string, containing amount, recipient, and expiry time.
The maximum amount sendable through a channel. Split into inbound liquidity (receivable) and outbound liquidity (sendable).
A tiny fee paid to nodes that relay your payment. Typically 0.0001–0.001% — extremely small.
A service that monitors for fraudulent channel closure attempts while your node is offline, responding automatically.
How Lightning Works
Two nodes open a channel by locking Bitcoin in a multisig wallet via on-chain transaction
All subsequent payments between them are just balance redistributions within the channel (no on-chain needed)
No direct channel? Payments route through intermediate nodes safely via HTLC
When closing a channel, the final balance state is recorded on-chain and settled in Bitcoin
Choosing a Lightning Wallet
Phoenix Wallet: non-custodial, very easy to use — #1 recommendation for Lightning beginners
Breez Wallet: non-custodial, includes POS features — great for small businesses
Muun Wallet: unified on-chain + Lightning, easy backup
Zeus Wallet: can connect to your own node, for advanced users
Custodial wallets (Wallet of Satoshi, etc.) are convenient but violate self-custody principles
Running a Lightning Node
A full node is required first — Lightning runs on top of a Bitcoin full node
LND, CLN (Core Lightning), Eclair — LND is most widely used with richest tooling
Umbrel, RaspiBlitz, etc. let you run a Lightning node alongside your full node easily
Choose channel partners wisely — opening channels with well-connected nodes is advantageous
Acquiring inbound liquidity is the biggest challenge for beginners
Learning Checklist
Understand the open-use-close flow of payment channels
Installed a Lightning wallet and loaded a small amount
Made a real Lightning payment (e.g., Bitcoin Beach, Bitrefill)
Understand inbound/outbound liquidity concepts
Created a Lightning address (user@domain.com format)