Electrum

Electrum is free, open-source Bitcoin wallet software for desktop and Android. It keeps private keys on the user's device, specializes in Bitcoin transaction control, and uses indexed Electrum servers with SPV checks instead of downloading and validating the whole blockchain locally.

A Bitcoin-only wallet with seed-based recovery

A deterministic Electrum seed generates the wallet's private keys and restores the wallet; the password protects the local wallet file and is replaceable by restoring from the seed. Electrum does not operate a hosted balance or hold a recovery key for the user.

The focused scope is intentional. Electrum handles Bitcoin on-chain transactions and Lightning functionality denominated in Bitcoin, not Ethereum tokens, Solana assets or a browser-dapp account. It can also work with hardware signers and watch-only wallets, separating public balance tracking from private-key signing.

Server-indexed history with explicit privacy boundaries

Electrum uses servers for address history, transaction broadcasts and fee estimates. Private keys do not go to those servers, and SPV checks confirmed transaction information, which keeps the client light and fast compared with a full blockchain download.

The trade-off is that the main server can associate subscribed wallet addresses and see the user's IP address; it is also trusted for unconfirmed transaction information and can omit relevant history. Selecting a server or running a personal Electrum server changes who receives address queries, without turning Electrum into a full Bitcoin node.

UTXO controls, offline signing and multisig

Electrum constructs Bitcoin transactions from available UTXOs, supports dynamic fee estimates, and can use replace-by-fee or child-pays-for-parent when their transaction conditions are met. These tools address mempool fee conditions; they do not make a confirmed payment reversible.

An online watch-only wallet can prepare an unsigned transaction while an offline wallet or hardware device supplies the signature. Multisignature can make a spending policy require several cosigners, such as two of two, with partially signed transactions passed by file, QR code or an encrypted cosigner-pool route.

A lighter alternative to a full node, not a multichain wallet

Sparrow is a close alternative for PSBT workflows, hardware-wallet support, multisig and UTXO-level coin and fee control. It emphasizes a detailed transaction editor, labeling and built-in Tor, while Electrum adds its own lightweight server model and Lightning-related tools.

Bitcoin Core is the stronger choice when independent full-node validation and peer-to-peer participation are the priority; it uses much more local storage and resources. MetaMask serves a different need entirely, combining browser-based EVM signing with multichain accounts rather than Electrum's Bitcoin-native transaction controls.