What is Channel Balance on the Lightning Network?
Channel balance is how the bitcoin in a Lightning channel is split between its two sides. The local balance is the part you can send. The remote balance is the part your peer can send, which is what you can receive. The two always add up to the channel's capacity, less small reserves. A node's total balance is the sum across all its channels, plus any on-chain funds it holds.
Why balance matters
A payment needs enough balance on the sending side of every channel along its route. Capacity alone does not tell you that. Two channels of the same size can behave very differently: one can forward a large payment, and the other, with its balance on the wrong side, cannot. Amboss has argued since 2022 that the gap between Lightning's capacity and its liquidity is the missing piece of network data, and channel balance is what closes it. See liquidity.
Why it is private
The network sees a public channel's total size, not its split. The split is private by default. Senders learn about it by probing: sending a payment designed to fail and reading the error. Amboss describes probing as revealing balance information without the target's consent. It is also used widely for rebalancing, payments and monitoring.
Estimating balance with research
Amboss research tries to reduce the cost of not knowing balances:
- Bayesian Binary Search. Probing finds a balance by bisecting the possible range. The method splits where balances are most likely to sit, rather than at the midpoint. On channel balance probing it gave a 3 to 6% efficiency gain and runs in production. Published in Algorithms, 2025.
- Channel balance interpolation. A machine learning model predicts a channel's split from node and channel features alone. It beat an equal-split baseline, where each side is assumed to hold half, by 10%. See the paper summary.
See also machine learning and the research page.
How Amboss handles channel balance
In October 2022 Amboss added opt-in balance reporting. Node operators send balances from Thunderhub, an open source node manager under the MIT licence, to Amboss Space. Each operator picks a privacy level:
- Private. Shared only with Amboss.
- Range. Shown publicly as 25%, 50% or 75%.
- Public. The specific percentage is shown to visitors.
The operator sees a Balance Report with on-chain balance, local and remote capacity per channel, and history from one hour to three months. Amboss notes that anyone can report false balances, so it builds services around the data operators share instead of ranking nodes on it. Read the announcement.
Managing balance
When balance drifts to one side, channel rebalancing moves it back. Operators can also add inbound balance by buying a channel on Magma. A balanced channel is not always the goal: a merchant mainly receiving payments wants a large remote balance.