Overview
Rebalancing is a liquidity management technique on the Lightning Network where a node operator redistributes funds across their channels to maintain effective routing capacity. As payments flow through channels, balances naturally shift to one side, reducing the channel's ability to route payments in the depleted direction. Rebalancing restores bidirectional capacity.
Why Rebalancing Is Needed
Before Rebalancing:
Channel A (Alice ↔ You) Channel B (You ↔ Bob)
┌─────────────────────┐ ┌─────────────────────┐
│ Alice: 0.1 │You: 0.9│ │ You: 0.1 │ Bob: 0.9│
│ │████████│ │ │█████████│
└─────────────────────┘ └─────────────────────┘
Can receive from Alice: 0.1 Can send to Bob: 0.1
Can send to Alice: 0.9 Can receive from Bob: 0.9
Problem: You can't route payments from Alice to Bob
(only 0.1 available on the Bob side)
After Rebalancing:
Channel A (Alice ↔ You) Channel B (You ↔ Bob)
┌─────────────────────┐ ┌─────────────────────┐
│ Alice: 0.1 │You: 0.5│ │ You: 0.5 │ Bob: 0.5│
│ │████ │ │████ │████ │
└─────────────────────┘ └─────────────────────┘
Can route payments in both directions more effectively
Rebalancing Methods
Circular Rebalancing
The most common method: the node sends a payment to itself through a circular route. Funds leave through the channel with excess local balance and return through the channel that needs more local balance. This costs routing fees to the intermediate nodes.
Submarine Swaps
A submarine swap moves funds between on-chain and off-chain. A node can drain a channel by swapping Lightning funds for on-chain bitcoin, then use those on-chain funds to open a new channel or use a reverse submarine swap to refill a depleted channel.
Loop In / Loop Out
Services like Lightning Loop provide automated submarine swaps. "Loop Out" moves sats from Lightning to on-chain (draining a channel), while "Loop In" moves on-chain sats into a Lightning channel (refilling it).
Cost Considerations
Rebalancing is not free. Circular rebalances pay routing fees to intermediate nodes, and the cost depends on the current fee market along available routes. Submarine swaps incur both routing fees and on-chain transaction fees. Node operators must weigh rebalancing costs against potential routing revenue.
Automated Rebalancing
Several tools and plugins (like rebalance-lnd, circular, or Balance of Satoshis) can automate the rebalancing process, monitoring channel balances and executing rebalances when imbalances exceed configurable thresholds. However, automated rebalancing without careful configuration can result in spending more on fees than the routing revenue it generates.
Common Misconception
Rebalancing does not create new liquidity — it redistributes existing liquidity across channels. If a node's total channel capacity is insufficient for the routing volume it wants to handle, rebalancing alone will not solve the problem; the operator needs to open additional or larger channels.