Based Rollups Explained: How They Work and Why They Matter

Blockchain scalability has remained a pressing concern in the crypto space ever since the technology’s inception. Several rollups were introduced, including ZK-Rollups, Optimistic Rollups, and now, Based Rollups, to address this challenge. While Zero-Knowledge (ZK) Rollups and Optimistic Rollups have dominated the Layer 2 conversation, a new paradigm, Based Rollups, is gaining traction among crypto enthusiasts, investors, and other stakeholders. It’s another scaling solution that has transformed the way rollups are designed, sequenced, and integrated into Ethereum’s evolving architecture. 

In this guide, we’ll unpack the what, how, and why of Based Rollups, from their architecture to their key benefits, in a deep enough way to keep blockchain enthusiasts intrigued. We’ll also compare Based Rollups with existing L2 blockchain rollups and uncover the unique value they bring to Ethereum’s roadmap.

Introduction to Based Rollups

Based Rollups, also known as L1-sequenced rollups, are a type of Layer 2 scaling solution for Ethereum that leverages the base layer (Layer 1) for transaction sequencing. Unlike traditional rollups, which employ their own sequencers, Based Rollups delegate the task of ordering transactions to the existing Ethereum validator network.

The concept of Based Rollups has gone through several updates since it was first introduced by Vitalik Buterin in 2021 under the name ‘Total Anarchy’. This idea meant that anyone could submit a batch of transactions at any time. The actual term ‘Based Rollup’ and its proper definition were later introduced by Justin Drake, a researcher at the Ethereum Foundation, in 2023. His main goal was to make Layer 2 rollups more closely connected to Ethereum itself, so they could benefit from Ethereum’s security, decentralization, and independence.

Why Do We Need Based Rollups?

Ethereum has been a pioneer in decentralized computation, but it wasn’t designed to handle the massive throughput required by modern DeFi, gaming, and social dApps on its own. Existing rollups, such as Optimistic Rollups and ZK-Rollups, attempt to bridge this scalability gap, but they come with their own set of trade-offs:

• Optimistic Rollups rely on fraud proofs and long withdrawal delays.
• ZK-Rollups offer faster finality but are computationally intensive and complex to implement.
• Both types typically rely on separate sequencers or validator sets, introducing some level of centralization and MEV (Miner Extractable Value) misalignment with Ethereum.

This is where Layer 2 Based Rollups step in, with a solution that promises to deliver the performance benefits of L2s while maintaining deep integration and alignment with Ethereum’s core consensus and incentive model.

We need Based Rollups because they:

• Eliminate the centralizing pressure of sequencers.
• Align rollup operation incentives with Ethereum validators.
• Minimize MEV extraction inefficiencies across layers.
• Reduce trust assumptions and censorship risks.

Layer 2 Based Rollups aim to simplify the L2 architecture while enhancing Ethereum’s security and neutrality.

The Architecture of Based Rollup 

To better understand Ethereum’s new rollup model, it’s important to first look at its architecture. Rollups are made up of four main layers: the settlement layer, data availability layer, consensus layer, and execution layer. These same layers also exist in Based Rollups. While the overall architecture remains the same, the approach used in based rollups is quite different, and this is what sets them apart from other rollups.

• Settlement Layer

This is where the rollup “settles” or finalizes its results. In Based Rollups, the results (proofs of what happened on Layer 2) are posted to Ethereum. 

If something goes wrong on Layer 2, one can still trust Ethereum to have a verified record. 

• Data Availability Layer

This layer ensures that all the data needed to rebuild or verify the rollup’s transactions is available to everyone. All this data in the Based Rollups is also stored on Ethereum. 

Anyone can read the block hashes posted to Ethereum and then access the full details of the transactions that happened in that block. So, the data is transparent and can be trusted.

• Consensus Layer

Blockchains have a separate system to agree on the order of transactions (called consensus). In Based Rollups, there is no separate consensus system. Instead, based rollups rely directly on Ethereum’s consensus. 

The order of transactions is decided by Ethereum’s validators, so the rollup just follows Ethereum’s lead.

• Execution Layer

This is the layer where the actual transaction processing happens. Based rollups run this part off-chain, on their own systems.

While Ethereum helps with security and data, the rollup handles running the apps and calculating results itself.

How do Based Rollups Work?

Based rollups leverage Ethereum’s native sequencer and validator set to integrate transactions directly into Layer 1 blocks. Here’s a high-level technical overview of how Based Rollups operate:

• Transaction Bundling by L1 Searchers / L2 Builders

On Ethereum (L1), there are specialized agents known as block searchers or block builders. These agents scan the mempool (a waiting area where unconfirmed transactions live) for valid Layer 2 transactions. They organize these transactions into “bundles,” basically, tightly packed groups of transactions that will later be inserted into Ethereum blocks.

• Block Proposer Adds L2 Blocks into Bundles

The Ethereum block proposer is the validator selected to propose the next block. The proposer includes multiple Layer 2 blocks in these bundles. These bundles now contain both Ethereum (L1) and rollup (L2) transactions in a packaged form.

• L1 Block Builder Constructs the Ethereum Block

The block builder (a system that builds candidate blocks) takes regular Ethereum transactions and bundled layer 2 blocks (from step 2) and inserts them into a single Ethereum block.

• Block Builder Sends the L1 Block to the Proposer

The constructed L1 block (now with both L1 and L2 data) is sent back to the Ethereum proposer for final submission.

• The Proposer Submits the Block into Ethereum

Finally, the proposer broadcasts the block to the Ethereum network. Once it’s accepted, the L2 transaction data becomes part of Ethereum’s canonical history. This means rollup activity is fully verifiable and finalized on Ethereum without a separate sequencer.

The Core Benefits of Based Rollups 

Based Rollups bring real, tangible benefits to Ethereum scaling. Let’s explore the key advantages:

• Proposer-Based Sequencing

Based Rollups outsource the role of sequencing to Ethereum proposers, which reduces infrastructure complexity. It removes the need for operating and securing a separate sequencer network or handling sequencer failures and misbehavior.

• Maximum Ethereum Alignment

MEV captured at the rollup level can be routed directly to Ethereum validators, incentivizing honest behavior and reinforcing Ethereum’s economic security. It makes Ethereum more resilient and helps avoid value leakage to off-chain actors.

• Increased Censorship Resistance

With sequencing performed by Ethereum validators, who rotate regularly, no single party can censor transactions for long. Compare this to traditional rollups with centralized sequencers who can arbitrarily censor users or reorder transactions.

• Fairer MEV Distribution

The MEV supply chain gets compressed. Rather than MEV being extracted by centralized L2 sequencers or external builders, it becomes part of the Ethereum proposer’s block reward, which makes the entire system more transparent and equitable.

• Lower Latency & Faster Inclusion

Since Based Rollups leverage Ethereum’s native block production, they eliminate the need to wait for Layer 2 sequencer consensus. It significantly enhances time-to-finality and delivers a smoother user experience, especially for latency-sensitive use cases like gaming, real-time finance, or high-frequency trading.

• Modular Compatibility with Rollup Frameworks

Based Rollups are implementation-agnostic. Whether you’re building a ZK-rollup, Optimistic Rollup, or even a Validium-style solution, the sequencing model can be integrated into existing frameworks like OP Stack or ZK Stack with some modifications.

Based Rollups vs. ZK-Rollups vs. Optimistic Rollups: A Comparison

Let’s dive deeper into how based rollups compare to traditional rollup types.

Conclusion

Ethereum’s rollup-centric roadmap faces numerous innovations, and Based Rollups is one of them that is shaping a future where scalability does not compromise decentralization or security. With the ease of integrating directly with Ethereum’s base layer for transaction sequencing, based rollups eliminate a key bottleneck in Layer 2 design: the centralized sequencer. This one such approach positions Based Rollups as a next-gen solution for Ethereum-native applications. Whether deployed in finance, gaming, identity, or cross-chain communication, Based Rollups offer a solid architectural foundation for trustless scalability.

While still early in adoption, the concept is gaining traction among researchers, developers, and infrastructure providers alike. Protocols like Espresso, OP Stack integrations, and modular rollup-as-a-service providers are already experimenting with variants of Based Rollups. No doubt, it’s high time to bet on Based Rollups in 2025. Partner with a reliable blockchain development company, Antier, to leverage Base L2 sequencer and rollup architecture for enhanced scalability, security, and decentralization.

Connect with us today for expert blockchain assistance!