Data gas is the unit of cost for publishing transaction data from a layer-2 (L2) rollup to a layer-1 (L1) blockchain, such as Ethereum. It is a distinct fee from the execution gas used for computation and state changes on the L1 itself. This cost is incurred because publishing data—typically in the form of calldata or blobs—consumes permanent storage on the L1, which is a scarce and valuable resource. The primary purpose of data gas is to price and manage the data availability layer, ensuring that the cryptographic proofs of an L2's state can be independently verified.
LABS
Glossary
Data Gas
Data gas is a blockchain fee mechanism that quantifies the cost of publishing and temporarily storing data, distinct from the gas used for transaction execution.
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definition
BLOCKCHAIN ECONOMICS
What is Data Gas?
A resource pricing mechanism for data availability on layer-2 rollups.
The introduction of EIP-4844 (Proto-Danksharding) on Ethereum created a dedicated marketplace for data gas via blob-carrying transactions. This established a separate fee market from execution gas, making L2 data posting costs more predictable and significantly cheaper. Data gas prices are determined by supply and demand for blob space in each block, fluctuating independently based on network congestion for data publication. Key metrics include the blobGasUsed and excessBlobGas in a block, which algorithmically adjust the base fee for the next block, similar to EIP-1559's mechanism for execution gas.
For end-users on rollups like Optimism, Arbitrum, or zkSync, data gas is a major component of the overall transaction fee, though it is usually abstracted away and paid by the rollup sequencer. The rollup batches thousands of user transactions, compresses the data, and pays the L1 data gas fee to post it. This architecture is fundamental to the rollup scaling trilemma, which balances scalability, security, and decentralization. Cheap and reliable data availability is critical for fraud proofs in optimistic rollups and validity proofs in zero-knowledge rollups to function correctly.
The evolution of data gas is central to Ethereum's danksharding roadmap, which aims to massively increase blob capacity. Future upgrades will allow the network to support many concurrent blobs per block, driving the cost of data availability down further and enabling higher throughput for L2s. This separates the cost of data availability sampling and storage from execution costs, creating a more efficient and modular blockchain stack. Understanding data gas is therefore essential for developers building on L2s and analysts modeling blockchain economics.
how-it-works
MECHANICS
How Data Gas Works
An explanation of the computational pricing mechanism for data availability on blockchains, distinct from execution gas.
Data gas is a specialized pricing mechanism that quantifies and charges for the cost of storing and transmitting data on a blockchain's data availability (DA) layer, separate from the computational cost of executing transactions. While standard execution gas (like Ethereum's gas) pays for CPU/GPU cycles, data gas pays for the persistent storage and bandwidth required to make transaction data publicly available for nodes to download and verify. This separation is fundamental to modular blockchain architectures, where execution, consensus, and data availability are decoupled into distinct layers.
The primary function of data gas is to manage the cost and scalability of blob-carrying transactions. On networks like Ethereum, following the Dencun upgrade, transactions can include blobs—large packets of data stored temporarily by consensus nodes. The data gas fee for a blob is calculated based on its size (in bytes) and the current demand for blob space, as determined by a dedicated fee market. This market operates independently from the main execution gas market, allowing for more predictable and often lower costs for applications that require significant data publication, such as Layer 2 rollups.
A key innovation in data gas models is the use of blob ephemerality. Unlike calldata, which is stored permanently on-chain, blobs are only guaranteed to be available for a short, fixed period (e.g., 18 days on Ethereum). This temporary storage significantly reduces the long-term state bloat burden on full nodes, which is why data gas fees can be lower than equivalent execution gas fees for the same data volume. After this period, the data can be pruned, assuming other parties like rollup sequencers or data availability committees have archived it.
The economic model of data gas creates distinct incentives. It allows high-throughput applications like optimistic rollups and ZK-rollups to post cryptographic proofs and transaction batches cost-effectively, which is essential for scaling. The separate fee market also prevents congestion from data-heavy transactions from spilling over and inflating the cost of simple value transfers or smart contract interactions. Protocols adjust their data gas parameters—like target blob count per block and fee update rules—to balance between network revenue, node resource requirements, and user affordability.
In practice, when a user interacts with a rollup, the rollup's sequencer bundles thousands of transactions, generates a validity proof or fraud proof, and posts this data as a blob to the parent chain (e.g., Ethereum). The sequencer pays the data gas fee for this publication. This action ensures the data is available for anyone to reconstruct the rollup's state and verify its correctness, which is the security foundation of the rollup. The efficiency of this process is why data gas is considered a cornerstone of the modern, scalable blockchain stack.
key-features
MECHANICS
Key Features of Data Gas
Data Gas is the unit of cost for publishing data to a blockchain's data availability layer. These features define its core economic and technical functions.
01
Unit of Measurement for Data
Data Gas is the standard unit for measuring and pricing the computational and storage resources required to publish data to a Data Availability (DA) layer, such as Ethereum's blobs or Celestia's blockspace. It quantifies the cost of making data publicly accessible for verification, separate from the execution gas used for smart contract computation. The price is typically determined by a market-based fee mechanism that responds to demand for block space.
02
Decouples Execution from Availability
A primary innovation of Data Gas is the decoupling of execution costs from data availability costs. On monolithic blockchains, a single gas fee covers both. With Data Gas:
- Execution Layer (L2s): Pays for smart contract processing.
- Data Availability Layer: Pays separately, via Data Gas, to post transaction data. This separation allows Layer 2 rollups to scale efficiently by posting compressed data in blobs, significantly reducing costs compared to posting all data directly to Ethereum's execution layer.
03
Fee Market Dynamics
Data Gas fees are not fixed; they are set by a market-based auction similar to Ethereum's EIP-1559 mechanism for execution gas. Key dynamics include:
- Base Fee: A protocol-determined price per unit of data, which adjusts per block based on network congestion from blob submissions.
- Priority Fee (Tip): An optional addition to incentivize validators/proposers to include a data submission faster.
- Burn Mechanism: The base fee is often burned (e.g., in Ethereum's EIP-4844), creating a deflationary pressure on the native token.
04
Enables Scalable Layer 2 Rollups
Data Gas is the foundational cost for optimistic rollups and zk-rollups. These Layer 2 solutions batch thousands of transactions, produce a proof or fraud proof, and then publish only the essential transaction data to the Layer 1 chain. By paying Data Gas for this compressed data publication, rollups inherit the security and availability guarantees of the base layer while offering users drastically lower transaction fees. The efficiency of Data Gas pricing directly impacts the cost savings passed to end-users.
05
Blob-Carrying Transactions
On Ethereum, Data Gas is consumed specifically by blob-carrying transactions introduced by EIP-4844 (Proto-Danksharding). These are special transactions that include large binary data objects called blobs.
- Each blob is ~128 KB and has its own Data Gas fee.
- Blobs are not accessible to the Ethereum Virtual Machine (EVM) and are deleted after ~18 days, keeping node storage requirements manageable.
- This structure creates a dedicated, low-cost data channel for rollups.
06
Resource Targeting & Limits
Data Gas systems implement strict resource limits per block to protect network stability and ensure predictable node performance. For example, Ethereum's EIP-4844 sets:
- Target: 3 blobs per block (0.375 MB).
- Limit: 6 blobs per block (0.75 MB). The base fee for Data Gas adjusts to keep blob usage near the target. This prevents the data layer from being overwhelmed and allows nodes to reliably sync and verify data availability without prohibitive hardware requirements.
etymology-and-evolution
TERM ORIGIN
Etymology and Evolution
This section traces the linguistic and conceptual lineage of the term 'Data Gas,' from its roots in Ethereum's computational model to its specialized role in modern blockchain scaling.
The term Data Gas is a compound noun formed by combining 'data'—referring to the raw transaction information—with 'gas'—a concept borrowed from Ethereum's fee mechanism for computational work. In Ethereum's original design, gas is a unit that measures the computational effort required to execute operations, paid for by users in the native currency (ETH). The innovation of Data Gas was to create a parallel, specialized metric for a different type of resource: the cost of publishing and storing data on the blockchain, particularly for Layer 2 scaling solutions.
The concept evolved directly from EIP-4844, known as Proto-Danksharding. This Ethereum upgrade introduced blobs (Binary Large OBjects), which are large packets of data attached to blocks but not processed by the Ethereum Virtual Machine (EVM). A new gas market was needed for this blob space, distinct from the gas used for execution. Thus, Data Gas (or blob gas) was born as the unit for pricing this dedicated data bandwidth, separating data availability costs from computation costs and creating a more efficient fee market for rollups.
The evolution of the term reflects a broader shift in blockchain architecture. Prior to EIP-4844, Layer 2 rollups like Optimism and Arbitrum published their transaction data directly to Ethereum's execution layer, paying high fees in standard gas. Data Gas formalizes and optimizes this process, acknowledging that data storage and availability are a fundamentally different resource constraint than CPU cycles. This semantic split mirrors the technical modularization of blockchain functions—execution, settlement, consensus, and data availability—into distinct layers with their own economic models.
In practice, Data Gas prices are determined by a separate, EIP-1559-style fee market with its own base fee and capacity target (initially 3 blobs per block). This market is designed to be more stable and predictable than execution gas for data-heavy operations. The term has now become standard lexicon when discussing the economics of data availability layers, validiums, and volitions, representing a key cost component for any application relying on scalable data publishing to a base layer like Ethereum.
EVM GAS MECHANICS
Data Gas vs. Execution Gas
A comparison of the two primary gas types used to price and allocate resources on Ethereum and other EVM-based blockchains.
| Feature | Data Gas (Blob Gas) | Execution Gas |
|---|---|---|
Primary Function | Pays for data availability and temporary storage of large data blobs (e.g., L2 batch data). | Pays for the computational execution of EVM opcodes and state changes. |
Resource Consumed | Bandwidth and temporary on-chain storage (for ~18 days). | CPU, memory, and permanent state storage. |
Pricing Model | Separate, floating fee market (EIP-4844). Price adjusts per block based on blob demand. | Primary fee market. Price adjusts per block based on execution and state update demand. |
Fee Target | Manages data bandwidth for Layer 2 scaling. | Manages block processing time and state growth. |
Unit of Measurement | Gas per blob. Each blob holds ~128 KB of data. | Gas per EVM operation (e.g., ADD opcode = 3 gas, SSTORE opcode = up to 22100 gas). |
Where It's Used | Exclusively for posting data in blob-carrying transactions (type 3). | For all standard transactions (transfers, swaps, contract deployments). |
Persistence | Data is pruned after ~18 days (Ethereum consensus layer). | Resulting state changes are permanent (until altered by another transaction). |
Example Cost (Ethereum Mainnet Approx.) | ~0.001 ETH per blob (variable, separate from execution). | ~21,000 gas base fee + priority fee for a simple transfer. |
ecosystem-usage
DATA GAS
Ecosystem Usage and Examples
Data Gas is a core mechanism for pricing and allocating data availability on modular blockchains. These examples illustrate how it functions across different networks and applications.
06
Economic Incentives & Security
Data Gas fees are not just a cost; they create critical economic incentives that secure the data availability layer.
- Validator Incentives: Fees reward nodes for storing and serving historical data, ensuring data retrievability.
- Spam Prevention: The gas market dynamically prices data space, preventing network spam and denial-of-service attacks.
- Resource Alignment: Pays for the real resource cost—bandwidth and storage—aligning user payments with provider costs. Without these fees, DA layers would be vulnerable to economic attacks.
security-considerations
DATA GAS
Security and Economic Considerations
Data Gas is a mechanism for pricing and allocating the cost of data availability and storage on a blockchain, acting as a critical resource for network security and economic sustainability.
01
Core Function: Pricing Data Availability
Data Gas is the unit of account for the cost of publishing data to a blockchain. It is distinct from execution gas, which pays for computation. Its primary function is to:
- Price blob space on layer-2 rollups (e.g., Ethereum's EIP-4844 blobs).
- Incentivize validators to store and propagate this data for a limited window.
- Prevent spam by making excessive data posting economically prohibitive.
02
Economic Security & Validator Incentives
The Data Gas market ensures network security by properly compensating the actors responsible for data availability. Key mechanisms include:
- Fee Burn: A portion of Data Gas fees may be burned (e.g., base fee), creating a deflationary pressure and aligning validator rewards with network usage.
- Minimum Bid: Systems often have a reserve price per unit of data to guarantee a baseline reward for validators, securing the data availability layer.
03
Resource Scarcity & Market Dynamics
Data Gas introduces scarcity for a new blockchain resource: dedicated data bandwidth. This creates a marketplace with predictable economic behaviors:
- Variable Pricing: Fees fluctuate based on demand for blob space, similar to Ethereum's base fee mechanism.
- Throughput Limits: A fixed capacity per block (e.g., 3 blobs/block) prevents congestion in the execution layer and creates a clear supply curve.
04
User & Developer Cost Predictability
For users and developers, Data Gas provides a more stable and predictable cost structure for data-heavy operations compared to using calldata. Benefits include:
- Cost Reduction: Posting data via blobs is typically ~10-100x cheaper than using execution layer calldata.
- Decoupled Pricing: Since Data Gas is for a separate resource, its price volatility is insulated from execution gas spikes caused by popular DeFi transactions.
05
Comparison: Data Gas vs. Execution Gas
These are complementary but distinct fee mechanisms on modern blockchains:
- Execution Gas: Pays for computation and state changes (e.g., running a smart contract). Fees go to the block proposer.
- Data Gas: Pays for data publication and availability (e.g., posting a rollup's batch). A significant portion of the fee is often burned. It has a separate, limited resource pool (blob space).
FAQ
Common Misconceptions About Data Gas
Clarifying frequent misunderstandings about Data Gas, a critical concept for scaling Ethereum and other Layer 2 solutions.
Data Gas is the unit of cost for publishing transaction data to Ethereum's base layer, while regular gas is the unit of computational cost for executing transactions. Data Gas is consumed when Layer 2 (L2) rollups, like Optimism or Arbitrum, post compressed transaction data (called calldata) to Ethereum's Layer 1 (L1) for security and finality. This is distinct from the execution gas used within the L2's own virtual machine to process the logic of those transactions. The separation allows for more predictable and efficient scaling, as data availability costs are decoupled from execution costs.
DATA GAS
Technical Details
Data Gas is a fundamental resource in blockchain networks, distinct from execution gas, that specifically pays for the cost of storing data on-chain. This section details its mechanics, calculation, and role in scaling solutions like Ethereum's EIP-4844 and Layer 2 rollups.
Data Gas is a specialized unit of measurement and pricing for the cost of storing data on a blockchain, separate from the execution gas used for computation. While execution gas pays for CPU/GPU cycles (like running smart contract code), data gas pays for the persistent storage of data in a block. This distinction is critical for scaling, as data storage is often the primary bottleneck and cost driver, especially for Layer 2 rollups that post large batches of transaction data to a base layer like Ethereum. The separation allows for independent optimization and pricing of these two distinct resources.
DATA GAS
Frequently Asked Questions (FAQ)
Essential questions and answers about Data Gas, the mechanism for pricing data availability on Ethereum and Layer 2 rollups.
Data Gas (or blob gas) is the unit of cost for publishing transaction data to Ethereum's blob-carrying transactions, introduced with EIP-4844 (Proto-Danksharding). It works by creating a separate, temporary data storage space called a blob, which is priced independently from regular execution gas. The cost of data gas is determined by a dedicated fee market that targets a specific number of blobs per block, making data availability for Layer 2 rollups significantly cheaper than storing data directly in calldata. Blobs are automatically pruned from full nodes after approximately 18 days, optimizing long-term storage costs while ensuring data is available for verification during the critical dispute window.
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