Layer 1 Blockchain Explained: What Is L1 in Crypto?
A Layer 1 (L1) is the base blockchain — the foundational network that processes transactions, stores data, and enforces consensus rules without relying on any other chain. Bitcoin and Ethereum are the two most important Layer 1s in existence.
What makes a Layer 1
A Layer 1 is self-sufficient: it has its own consensus mechanism, its own validator or miner set, and its own native token used to pay transaction fees. All transactions on a Layer 1 are finalized directly on the chain itself. There is no parent chain to appeal to for security.
Bitcoin uses Proof of Work consensus: miners expend computational energy to earn the right to add blocks and collect the block reward. Ethereum transitioned to Proof of Stake in 2022, where validators lock ETH as collateral to propose and attest blocks.
The scalability challenge
Layer 1 blockchains face a fundamental tradeoff: higher throughput requires larger blocks or faster block times, which increase node hardware requirements and reduce decentralization. Bitcoin processes ~7 transactions per second; Ethereum processes ~15–30. Neither can compete with Visa's ~24,000 TPS on their base layers.
The response to this limitation is the Layer 2 ecosystem. Polygon and other L2 networks offload computation to a separate layer, then batch and settle proofs back to Ethereum, achieving thousands of TPS while inheriting Ethereum's security.
Evaluating a Layer 1
When reading a Layer 1 whitepaper, the key questions are: What consensus mechanism is used, and what are its security assumptions? How decentralized is the validator/miner set? What is the native token's inflation schedule? What is the developer ecosystem like today? ChainClarity's analyses cover all of these.
Layer 1 projects on ChainClarity
- Bitcoin — the original Layer 1, focused on censorship- resistant value storage
- Ethereum — programmable Layer 1, home of smart contracts and DeFi
- Polygon (POL) — Ethereum Layer 2 scaling suite
- Chainlink — oracle network securing data feeds for Layer 1 smart contracts
Browse all Layer 1 blockchains →
Frequently asked questions
What is a Layer 1 blockchain?
A Layer 1 (L1) is a base-layer blockchain — the foundational network that handles transaction processing, data storage, and consensus directly. Bitcoin and Ethereum are Layer 1s. They are the source of truth that Layer 2 networks anchor to for security.
What is the difference between Layer 1 and Layer 2?
A Layer 1 does all computation and storage on its own chain. A Layer 2 offloads computation to a separate network, then periodically settles transaction summaries or proofs back to the L1. Layer 2s inherit L1 security while achieving much higher throughput. Polygon is an Ethereum Layer 2; Bitcoin Lightning is a Bitcoin Layer 2.
Why can't Layer 1 blockchains just process more transactions?
Increasing block size or reducing block time increases the hardware requirements for running a full node. As node requirements rise, fewer people run them — centralizing the network and reducing security guarantees. This is the fundamental tradeoff in the blockchain trilemma: decentralization, security, and scalability cannot all be maximized simultaneously on a single Layer 1.
What consensus mechanisms do Layer 1 blockchains use?
The two dominant consensus mechanisms are Proof of Work (PoW) and Proof of Stake (PoS). Bitcoin uses PoW: miners compete to solve a cryptographic puzzle, consuming energy proportional to their probability of winning the block reward. Ethereum transitioned to PoS in 2022: validators lock up ETH as collateral and are selected to propose blocks, earning staking rewards in return.
How do you evaluate a Layer 1 blockchain?
Key metrics: throughput (transactions per second), finality time (how long before a transaction is irreversible), node count and distribution (decentralization), token distribution and inflation schedule (tokenomics), and developer ecosystem size. ChainClarity's whitepaper analyses cover all of these for every L1 on the platform.