An altcoin is a cryptocurrency other than Bitcoin. The term combines “alternative” and “coin,” and it broadly covers thousands of blockchain projects that aim to provide different functions, tradeoffs, or innovations compared with Bitcoin’s original design.
What qualifies as an altcoin
In everyday crypto usage, “altcoin” usually means any non-Bitcoin token or coin. Some communities also exclude Ethereum because of its size and influence, but in most market and educational contexts, Ethereum is still considered an altcoin because it is not Bitcoin. Altcoins can be native coins that run on their own blockchain, such as Litecoin or Solana, or tokens issued on top of an existing smart contract platform, such as many ERC-20 tokens on Ethereum.
Why altcoins exist and how they differ
Altcoins often emerge to address perceived limitations or to target specific use cases. Smart contract platforms like Ethereum introduced programmable transactions, enabling decentralized finance, NFTs, and on-chain governance. Payment-focused coins, such as Litecoin, experimented with different transaction speeds and network parameters. Privacy-oriented projects have explored methods to make transactions harder to trace. There are also asset-backed or value-pegged tokens, like widely used stablecoins, which prioritize price stability for trading and payments rather than long-term appreciation.
Because each altcoin has its own rules, security model, and ecosystem, risks vary widely. Some networks are highly decentralized and battle-tested, while others depend on smaller validator sets, centralized teams, or experimental code, which can increase technical and governance risk.
Why altcoins matter
Altcoins drive much of crypto’s innovation, competition, and experimentation, shaping new applications and pushing the broader ecosystem beyond simple peer-to-peer payments.