Layer 1 Blockchains

In one minute

• What they are: Layer 1s (L1s) are the base blockchains like Bitcoin, Ethereum, and Solana. They order transactions, store the ledger, and provide security.
• Native asset: Each L1 has its own coin (e.g., BTC, ETH, SOL) used for fees and incentives.
• Apps on top: Many L1s support smart contracts, which power dApps, DeFi, NFTs, games, and more.
• How they differ from L2s: L2s run on top of an L1 and settle back to it; L1s don’t rely on another chain for security.

Reminder: Educational only — not financial advice. Never share your seed phrase.

What makes an L1 an L1?

Popular examples (at a glance)

• Bitcoin (BTC): PoW, simple scripting, strong focus on security and decentralization; often treated as a store of value.
• Ethereum (ETH): PoS, rich smart-contract platform (EVM); huge developer ecosystem.
• Solana (SOL): High-throughput smart-contract L1 with fast confirmation times.
• Cardano (ADA): PoS smart-contract platform with research-driven development.

Examples are for education only, not endorsements.

L1s vs L2s (why people build Layer 2s)

• Security base: L1s provide their own security. L2s inherit security from an L1 by periodically sending compressed proofs or batches to it.
• Throughput: L1 block space is scarce. L2s help scale by handling many transactions off-chain or in batches.
• Costs: L2s can be cheaper per transaction, but still depend on L1 fees for settlement.
• Bridges: Moving assets across L1s/L2s often uses bridges; bridges add extra risk (smart-contract bugs, hacks).

More in our Layer 2s guide.

Design trade-offs (why L1s feel different)

• Scalability vs decentralization: Bigger blocks and faster finality can raise hardware requirements, which may reduce how many people can run nodes.
• Fee model: Some L1s have variable fees (auction-style). Others target predictable fees via protocol design.
• State growth: The ledger grows over time. Efficient storage and pruning matter for long-term health.
• Smart-contract model: EVM-compatible L1s run Solidity/Vyper contracts. Non-EVM L1s use different languages and tooling.
• Latency & finality: Block times and finality mechanisms determine how “settled” a transaction feels.

Fees, addresses, and wallets (quick basics)

• Gas: A fee paid in the L1’s native coin to process your transaction.
• Address formats: Addresses look different across L1s. Sending to the wrong type of address can lose funds.
• Token transfers: Tokens on an L1 (like ERC-20s on Ethereum) still require the native coin for gas.
• UTXO vs account-based: Some L1s (e.g., Bitcoin) use UTXOs; others (e.g., Ethereum) are account-based. Wallet UX differs slightly.

See also: Gas & fees and Wallets & keys.

Security basics

• Economic security: Attacking a large L1 is costly due to mining hardware (PoW) or staked value (PoS).
• Honesty incentives: PoS slashing penalties and PoW costs discourage misbehavior.
• Client diversity: Multiple independent node implementations reduce single-software risk.
• Upgrades & forks: L1s evolve via upgrades; contentious changes can lead to forks (two separate chains).

When would I pick an L1 for my app?

• Users & wallets: Do your users already have wallets on this L1?
• Fees & speed: Are transactions affordable and fast enough for your use case?
• Tooling: SDKs, indexers, dev docs, and testnets make building easier.
• Ecosystem: Exchanges, on-ramps, oracles, and data providers available?
• Regulatory posture: Consider regional policies and compliance needs.

Beginner mistakes to avoid

1. Wrong network: Sending assets on the wrong L1 or to an incompatible address.
2. No gas: Forgetting to keep a little native coin for fees.
3. Copycat tokens: Not verifying the token contract address from official sources.
4. Bridge risks: Assuming bridges are risk-free; always double-check the bridge’s reputation.

Educational content only. Do your own research.