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What is a light client?
A light client is blockchain software that checks the chain's data without downloading and storing every block. It keeps only block headers and verifies the specific information it needs against them, so it can run on a phone or in a browser.
What it means for you
A wallet that relies only on an RPC provider takes that provider's word for your balance and transaction status. A wallet with a built-in light client can check that data against headers signed by the network's own validators, so a dishonest or compromised provider has a harder time showing you false information.
How it works
On Ethereum, a light client follows block headers signed by the sync committee: a randomly selected group of 512 validators that changes roughly every 1.1 days. Each header carries the committee's aggregated signature and a bitfield showing who signed, so the client can confirm that at least two-thirds of the committee approved it. To learn a balance or a contract value, the client requests the data from a provider and verifies it against a header it already accepts, instead of trusting the provider directly. This uses a tiny amount of computing power, memory and storage.
Sources: ethereum.org: Light clients, ethereum.org: Nodes and clients · checked 4 October 2026
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