A Layer 1 is a base blockchain that settles its own transactions and secures itself, without depending on another network underneath. Bitcoin, Ethereum, Solana, and Avalanche all qualify.
The term exists only because Layer 2 does, and before scaling networks started settling their transactions back to Ethereum there was simply no reason to distinguish between one kind of blockchain and another. Before scaling networks arrived, nobody needed a word for the thing underneath.
What makes a chain a Layer 1
Four properties, and all four must hold.
- Own consensus. The network validates its own transactions, whether through Proof of Work or Proof of Stake.
- Own security budget. Miners or validators are paid by the chain itself, from its own block rewards and fees.
- Own settlement. Transactions are final on this chain. Nothing gets posted elsewhere for confirmation.
- Native token used for fees. Gas is paid in the chain's own asset.
Relying on another chain for security or settlement disqualifies it, whatever the marketing says.
The scalability trilemma
Every Layer 1 designer works against a single constraint that has shaped almost every architectural decision made in the industry over the past decade.
Proposed by Vitalik Buterin, the trilemma says a chain can optimize for two of three properties: decentralization, security, and scalability. Getting all three at once has not been achieved.
| Chain | Prioritizes | Trade-off accepted |
|---|---|---|
| Bitcoin | Security and decentralization | Low throughput, roughly seven transactions per second |
| Ethereum | Security and decentralization | Limited base-layer throughput, scaling moved to Layer 2 |
| Solana | Scalability and security | Higher hardware requirements for validators |
| Avalanche | Scalability and finality | Ecosystem fragmentation across custom chains |
Every design is a position on that triangle. Read a chain's marketing against it and you see what got given up.
How base blockchains try to scale
Four broad approaches, used in combination.
Bigger or faster blocks. Throughput rises directly. So does the hardware cost of running a node, which pushes toward centralization.
Better consensus. Avalanche's repeated random sampling reaches finality in about a second. Solana's approach targets high throughput.
Sharding. Splitting the network into parallel segments that process transactions simultaneously.
Moving execution elsewhere. Ethereum's chosen path. Keep the base layer small and secure. Let Layer 2 networks handle volume.
In measurable terms that last strategy worked. After Ethereum's Dencun upgrade in March 2024 shifted rollup data into blobs, mainnet utilization fell to roughly 50% even as total network activity grew.
Layer 1 vs Layer 2
| Layer 1 | Layer 2 | |
|---|---|---|
| Security | Its own | Inherited from the Layer 1 |
| Settlement | Final on this chain | Posted back to the Layer 1 |
| Typical fees | Higher | 90 to 99% lower |
| Examples | Bitcoin, Ethereum, Solana | Arbitrum, Base, OP Mainnet |
What to look at when comparing blockchains
- Security budget. What does attacking the chain cost, and who pays for that defense?
- Validator distribution. Concentrated validators mean a smaller group can coordinate.
- Real activity. Transaction counts inflate easily. Harder to fake are active addresses and fee revenue.
- Finality time. How long before a transaction becomes genuinely irreversible, which differs from confirmation.
- Developer activity. Without builders, chains stop shipping, whatever the token does.
- Ecosystem depth. Liquidity and applications concentrate, and a chain with neither is a chain nobody uses.
What a base network does not guarantee
- Decentralization by default. Plenty of chains marketed as Layer 1s run few validators controlled by few parties.
- Security proportional to marketing. Security comes from the cost of attacking, which is measurable and frequently goes unmentioned.
- That the token accrues value. Chains can be widely used while their token captures little of that usage.
- Longevity. Dozens launched with substantial funding and now process almost nothing.
Where mb.io fits
Base assets of the whole market are Layer 1 tokens, and access to them requires a regulated venue.
mb.io is a regulated crypto spot exchange backed by MultiBank Group, a financial institution founded in 2005 that serves more than 2 million clients across 100+ countries.
- Regulated by VARA in the UAE and AUSTRAC in Australia
- 10/10 security score from Hacken, an independent blockchain security auditor
- Institutional-grade MPC custody powered by Fireblocks, with segregated client funds
- A curated list of assets, so you're not sorting through thousands of tokens to find the ones worth trading
- Buy, sell, and swap in three steps, from sign-up to purchase
- 24/7 multilingual customer support
Open your account and start trading on mb.io.
Frequently asked questions
What is a Layer 1 blockchain?
A base network running its own consensus, paying for its own security, and settling its own transactions. Bitcoin, Ethereum, Solana, and Avalanche are examples.
What is the difference between Layer 1 and Layer 2?
A Layer 1 secures itself. Processing transactions separately and posting results back, a Layer 2 inherits that chain's security while charging far lower fees.
What is the blockchain trilemma?
The proposition that a chain can optimize for two of decentralization, security, and scalability, but not all three simultaneously. Every Layer 1 design represents a choice about which to sacrifice.
Is Solana a Layer 1?
Yes. Running its own consensus and settling its own transactions, it prioritizes throughput and accepts higher validator hardware requirements as the trade-off.
Which Layer 1 is best?
They optimize for different things, so the answer depends on the use case. Security budget, validator distribution, finality time, and ecosystem depth all matter more than headline transaction speeds.
Do Layer 1s compete with each other?
For developers, users, and liquidity, yes. Scaling through Layer 2 networks rather than competing on base-layer throughput is Ethereum's strategy, which is a different bet from Solana's.
What is a Layer 0?
A term for protocols letting independent blockchains connect and communicate, such as interoperability frameworks. More a marketing category than a technical one.
Can a Layer 1 become a Layer 2?
Some have tried, converting into rollups that settle on Ethereum. Giving up an independent security budget buys inherited security and shared liquidity.
