What is a Layer 1 Blockchain?

A Layer 1 (L1) blockchain serves as the foundational layer in the blockchain ecosystem. It’s the primary blockchain infrastructure on which other secondary networks and applications, known as Layer 2 (L2), can be built. Bitcoin and Ethereum are the two largest and most well-known L1 blockchains, providing the necessary security and infrastructure to support L2 solutions.

Example of Layer 1 and Layer 2 Interactions

An example of an L1 and L2 working together is Ethereum and Optimism:

  • Ethereum is the L1 blockchain, responsible for security through its proof-of-stake (PoS) consensus.
  • Optimism is an L2 that relies on Ethereum for security and data availability, posting all transactions to Ethereum’s blockchain. This setup helps secure Optimism while providing faster transactions and lower fees than Ethereum alone.

Key Characteristics of Layer 1 Blockchains

Layer 1 blockchains generally:

  • Store transaction history in a decentralized ledger.
  • Use a consensus mechanism to validate and secure the network.
  • Feature a native cryptocurrency for paying transaction fees.
  • Provide infrastructure for secondary networks (L2s) and decentralized applications (dApps).
  • Serve as the primary source for transaction verification and settlement.
  • Often experience slower speeds and higher costs compared to L2 solutions.

Consensus Mechanisms: A Core Element of Layer 1

Consensus mechanisms allow nodes to reach an agreement on the blockchain’s state, preventing malicious activity. They incentivize honest actors and protect against issues like double-spending and Sybil attacks. The two most common consensus mechanisms are:

  • Proof-of-Work (PoW): Used by Bitcoin, requiring miners to expend computational power to validate transactions.
  • Proof-of-Stake (PoS): Used by Ethereum, where participants lock up a certain amount of crypto as collateral to secure the network.

Other variations include delegated PoS, proof-of-authority, proof-of-history, hybrid PoW/PoS, proof-of-burn, and delayed PoW.

Read on: Proof-of-stake vs Proof-of-work

Major Layer 1 Blockchains

  • Bitcoin: The first and most valuable public blockchain, operating on PoW. Its native currency, BTC, is used for transaction fees. To address slow speeds, Bitcoin has L2 solutions like the Lightning Network.
  • Ethereum: The second-most valuable blockchain, known for pioneering smart contracts and supporting dApps, NFTs, and tokens. Ethereum’s PoS mechanism supports a scalability roadmap, though it still faces congestion and high fees, partially addressed by L2 rollups.

Alternative Layer 1 Blockchains

The growth of blockchain has led to the development of alternative L1s, such as:

Solana and Cardano, offer smart contract capabilities with a focus on scalability.

  • Solana: Provides fast and low-cost transactions, though it trades some decentralization for performance.
  • Cardano: Utilizes the unique Ouroboros consensus and UTXO model, which is distinct from Ethereum’s account-based ledger.

Other notable L1s include Avalanche, BNB Chain, Aptos, Algorand, and Tezos.

Layer 1 Vs. Layer 2 Blockchains

 

Property

Layer 1 (L1)

Layer 2 (L2)

Native Token

Required for transaction fees

Often used for governance

Gas Fee Payment

Paid in L1 native tokens

Some use ETH; others have unique tokens

Gas Fee Cost

Typically higher

Generally lower

Scalability

Limited due to security focus

Enhanced scalability

Security

Higher security and decentralization

More centralized, can affect security

Consensus

Integral to L1 security

Relies on L1 consensus

Layer 1 Blockchains List

Here is a list of Layer 1 blockchains:

  • Ethereum
  • Solana
  • Astar
  • Cronos
  • Kadena
  • Injective
  • Near Protocol
  • Avalanche
  • Cosmos
  • BNB Chain
  • Polkadot
  • Shardeum
  • Flare Network
  • 5ire
  • XDC Network
  • XPLA
  • Decimal
  • OmniaVerse Ecosystem
  • Areon Network
  • Innovator Chain
  • Alephium
  • Circular Protocol
  • HeLa
  • AIOZ W3S
  • START
  • WOW EARN CHAIN
  • OORT
  • Signal21
  • Saakuru
  • Klever
  • Quai Network
  • PLAYA3ULL GAMES
  • LayerOneX
  • Sunrise

Bottom Line

L1 blockchains play a foundational role in the crypto ecosystem, supporting innovations like DeFi, blockchain gaming, NFTs, and more. As L1 technology evolves, it paves the way for broader and more scalable blockchain applications.

FAQs

1. What is the first block created in the blockchain?

The first block in a blockchain is known as the genesis block. Serving as the blockchain's foundation, it’s typically hardcoded into the software. Unlike all subsequent blocks, the genesis block is unique because it doesn’t reference any previous block.

2. What are L1 blockchains?

Layer 1 (L1) blockchains are the main, foundational blockchains that handle all core functions, including transaction processing, consensus, and security. Examples include Bitcoin, Ethereum, and Solana. These blockchains operate independently without relying on external networks and provide the base layer for decentralized applications (dApps) and other blockchain solutions.

3. Is Solana an L1 or L2?

Solana is a Layer 1 (L1) blockchain. It operates as an independent, high-performance blockchain that processes transactions and manages consensus directly on its own network. Solana is known for its scalability and fast transaction speeds, utilizing a unique Proof of History (PoH) consensus mechanism combined with Proof of Stake (PoS).