Mempool Holdings S.A. de C.V. is a Bitcoin-only software company based in El Salvador, building tools that support Bitcoin’s development as a multi-layer ecosystem. Its best-known product, mempool.space, is a Bitcoin explorer used by individuals and companies worldwide. It visualizes the Bitcoin mempool, tracks pending transactions, and provides fee estimates, helping users understand network activity and plan transactions.

The company also offers explorers for the Liquid Network and El Salvador, powered by The Mempool Open Source Project. Its open-source software includes mempool/electrs, a fork of electrs, and applications available through platforms such as Start9 and Umbrel. Mempool Fixes relays transaction acceleration requests to miners to help prioritize transactions, while a premium offering provides advanced features and enterprise API rate limits. Mempool Research publishes on-chain analysis by Orange Surf, offering quantitative insights into the Bitcoin network.

The company’s stated principles include developing free, open-source software, making it available for community use and self-hosting, respecting user privacy, and funding its work through enterprise features rather than advertising or user tracking.