Ethereum Calldata excels at providing universal, permanent on-chain DA because it is stored directly in Ethereum's execution layer history. For example, Layer 2s like Arbitrum One and Optimism historically used it, guaranteeing that their state data is verifiable by any Ethereum node forever. This permanence comes at a premium cost, with calldata fees subject to the volatile gas market, often making it the most expensive component of an L2 transaction during network congestion.
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Comparisons
Ethereum Calldata vs Blobs: DA
A technical comparison for CTOs and architects on Ethereum's two primary data availability layers: traditional calldata and EIP-4844 blob-carrying transactions. We analyze cost efficiency, scalability limits, and architectural trade-offs for rollups and L2s.
Chainscore © 2026
introduction
THE ANALYSIS
Introduction: The Data Availability Battle on Ethereum
Ethereum's scaling evolution has created two primary data availability (DA) paths: the established calldata model and the new blob-carrying transactions introduced by EIP-4844.
EIP-4844 Proto-Danksharding Blobs take a different approach by creating a separate, low-cost data channel alongside mainnet blocks. This results in a fundamental trade-off: blobs are ~10-100x cheaper than equivalent calldata (e.g., ~$0.01 vs ~$1.00 for 125 KB) but are only stored by nodes for ~18 days before being pruned. This design, adopted by zkSync Era, Base, and Starknet, assumes long-term data availability will be handled by third-party services like EigenDA or Celestia.
The key trade-off: If your priority is maximum security, permanence, and minimizing external dependencies, calldata remains the gold standard. If you prioritize dramatically lower transaction costs for end-users and are comfortable with a modular DA stack, EIP-4844 blobs are the clear choice for modern, high-throughput rollups.
tldr-summary
Ethereum Calldata vs. Blobs
TL;DR: Key Differentiators
A direct comparison of Ethereum's two primary data availability (DA) layers, focusing on cost, capacity, and protocol-level trade-offs for rollups and dApps.
01
Ethereum Calldata (Pros)
Full EVM Accessibility: Data is permanently available and directly readable by smart contracts via msg.data. This is critical for on-chain proofs, dispute games (like in Optimism), and any application logic requiring direct contract access to historical data.
02
Ethereum Calldata (Cons)
Exponentially Expensive at Scale: Priced as part of block gas, costing ~$100+ per MB during congestion. This makes high-throughput rollups like StarkNet or zkSync prohibitively expensive, directly competing with user transactions for block space.
03
EIP-4844 Blobs (Pros)
Order-of-Magnitude Cost Reduction: Separate fee market with a target of ~$0.01 per MB. Designed for rollups, it decouples DA costs from execution gas, enabling sustainable scaling for protocols like Arbitrum, Optimism, and Base.
04
Ethereum Blobs (Cons)
Limited Persistence & Access: Data is pruned by nodes after ~18 days (4096 epochs). Not natively readable by the EVM—requires a precompile or external DA provider for historical retrieval, adding complexity for long-term data needs.
05
Choose Calldata For
- On-chain Verifiability: Fraud proofs or validity proofs that must be verified directly in a contract.
- Permanent, Contract-Readable Logs: Immutable data that dApps must query on-chain indefinitely.
- Low-Volume, High-Value Settlements: Where data cost is negligible compared to transaction value.
06
Choose Blobs For
- High-Throughput Rollups: L2s like Arbitrum Nova or zkSync posting 10k+ TPS of proof data.
- Cost-Sensitive Applications: Social, gaming, or DePIN dApps where <$0.01 fees are required.
- Future-Proof Scaling: Building on the dedicated DA layer (proto-danksharding) that Ethereum is optimizing for.
HEAD-TO-HEAD COMPARISON
Ethereum Calldata vs Blobs: Data Availability Comparison
Direct comparison of key metrics for on-chain data storage and L2 scaling.
| Metric | Calldata (Execution Layer) | Blobs (EIP-4844 / Proto-Danksharding) |
|---|---|---|
Cost per KB (Post-EIP-4844) | $0.50 - $2.00 | $0.01 - $0.05 |
Target Throughput (Data per Block) | ~190 KB | ~1.3 MB |
Data Persistence | Permanent (Full History) | Temporary (~18 Days) |
Primary Use Case | Contract Execution & L1 Storage | L2 Rollup Data Publication |
Gas Market Competition | High (Shares with L1 TXs) | Low (Separate Fee Market) |
EVM Accessible | ||
Mainnet Activation | 2015 (Genesis) | 2024 (Dencun Upgrade) |
DATA AVAILABILITY COST COMPARISON
Ethereum Calldata vs Blobs: Cost Analysis
Direct comparison of cost structures for on-chain data availability on Ethereum.
| Metric | Calldata (Legacy) | EIP-4844 Blobs |
|---|---|---|
Avg. Cost per Byte | ~16 gas | ~0.125 gas |
Typical Rollup Cost per Tx | $0.50 - $2.00 | < $0.01 |
Data Capacity per Block | ~100 KB | ~1.7 MB (3 blobs) |
Permanent Storage on Mainnet | ||
Data Pruning Timeline | N/A (Permanent) | ~18 days |
Primary Fee Market | Competes with L1 Txs | Isolated (Blob Gas) |
pros-cons-a
DATA AVAILABILITY (DA) COMPARISON
Pros & Cons: Ethereum Calldata vs Blobs
Key strengths and trade-offs for Ethereum's two primary data availability layers. The choice impacts L2 economics, security, and future-proofing.
01
Ethereum Calldata: Pros
Universal Compatibility: Works with all existing Ethereum clients and tools (e.g., Geth, Erigon, Etherscan). This matters for legacy L2s like Optimism Classic or any custom rollup that hasn't upgraded.
Maximum Security: Data is processed and stored by all full nodes, inheriting Ethereum's full consensus and execution-layer security. This is critical for high-value, low-trust applications where DA guarantees are paramount.
02
Ethereum Calldata: Cons
Prohibitively Expensive: At ~$100 per 100KB during peak congestion, it's unsustainable for high-throughput L2s. This directly increases end-user transaction fees.
Blockspace Inefficiency: Competes with EVM execution for the same scarce resource, leading to network congestion and higher gas costs for all Ethereum users, not just rollups.
03
Ethereum Blobs (EIP-4844): Pros
Cost-Effective Scaling: Provides 100x cheaper DA ($0.01 per 100KB target) via dedicated blobspace. This is essential for cost-competitive L2s like Arbitrum, Optimism, and zkSync to reduce fees.
Future-Proof Design: Built as a precursor to full Danksharding. Adopting blobs now aligns with Ethereum's long-term scaling roadmap and Proto-Danksharding (EIP-4844) tooling like blob transactions.
04
Ethereum Blobs (EIP-4844): Cons
Temporary Storage: Data is only guaranteed available for ~18 days (4096 epochs). This requires L2s to implement their own long-term data storage solutions, adding operational complexity.
New Client Requirements: Requires nodes to run EIP-4844 compatible clients (e.g., Besu, Nethermind v1.23+). This matters for validator and infrastructure providers managing upgrades.
pros-cons-b
Ethereum Calldata vs Blobs: DA
Pros & Cons: EIP-4844 Blobs
Key strengths and trade-offs for data availability on Ethereum L1.
01
Calldata: Proven Security
Full Ethereum consensus security: Data is validated by all nodes, making it immutable and censorship-resistant. This is critical for high-value state transitions and bridges where data integrity is paramount.
02
Calldata: Universal Compatibility
No client or tooling upgrades required: Works with all existing Ethereum infrastructure (e.g., Etherscan, The Graph, Hardhat). This matters for protocols with complex dependency chains or those requiring immediate, broad accessibility.
03
Calldata: High & Volatile Cost
Expensive gas consumption: At ~16 gas per byte, posting 100KB costs ~0.1 ETH during high congestion. This is prohibitive for high-throughput L2s like Optimism or Arbitrum, which need to post large batches frequently.
04
Calldata: Network Bloat
Permanent state growth: All data is stored forever on execution clients, increasing hardware requirements for node operators. This creates long-term scaling challenges for the base layer's decentralization.
05
Blobs: 10-100x Cost Reduction
Separate fee market: Blob data has its own gas pricing (blob gas), decoupled from EVM execution. This leads to ~$0.01 per 125KB blob vs. ~$100+ for equivalent calldata, enabling cheaper L2 transaction fees.
06
Blobs: Scalable Data Throughput
Dedicated bandwidth: Targets ~0.375 MB per block (3 blobs), scaling to ~1.3 MB with future upgrades. This supports rollups like Base and zkSync posting proofs and state diffs without congesting the main net.
07
Blobs: Prunable Data
Temporary storage: Blobs are pruned by consensus nodes after ~18 days (4096 epochs). This preserves node disk space while providing sufficient window for fraud/validity proofs, a core design for modular data availability.
08
Blobs: New Integration Complexity
Requires upgraded infrastructure: Clients must support EIP-4844, and tools (e.g., RPC providers, indexers) need new APIs. This adds integration overhead for dApps and bridges that directly consume blob data.
CHOOSE YOUR PRIORITY
Decision Framework: When to Use Which
Calldata for Cost Efficiency
Verdict: Use for small, frequent, or non-permanent data. Strengths: Calldata is the default and only option for direct contract execution. It's ideal for small payloads (<~1KB) where the data is essential for on-chain logic and state changes. Its cost scales linearly with size and is fully covered by the gas fee. Use for function arguments, small proofs, or when interacting with existing contracts like Uniswap or Aave that require direct input.
Blobs for Cost Efficiency
Verdict: Use for large, archival data where cost-per-byte is critical. Strengths: Blobs offer a ~10x reduction in cost per byte for large data (typically >~2KB). The cost is decoupled from gas and burns separately via EIP-4844. This is optimal for rollups (Arbitrum, Optimism, zkSync) posting batch proofs and transaction data, or for applications storing large datasets (like game state snapshots or decentralized social graphs) where the data needs to be available but not processed by the EVM.
verdict
THE ANALYSIS
Verdict & Strategic Recommendation
A final assessment of Ethereum's calldata and blob-carrying transactions for data availability, based on cost, capacity, and long-term roadmap.
Ethereum Calldata excels at providing the highest security and universal compatibility for on-chain data because it is processed and stored by all consensus nodes. For example, before EIP-4844, protocols like Optimism and Arbitrum used calldata, paying an average of $0.25-$2.00 per transaction in gas fees for this data, which was a primary scaling bottleneck. Its permanence and direct verifiability make it the gold standard for critical state data and high-value, low-volume applications.
EIP-4844 Blobs (Proto-Danksharding) take a different approach by introducing a separate, ephemeral data channel with a targeted 1 MB per block capacity. This results in a dramatic cost reduction—often 10-100x cheaper than calldata—by separating data availability from execution gas markets and implementing a short 18-day storage window. The trade-off is the temporary nature of the data, requiring Layer 2 sequencers or third-party services like EigenDA or Celestia to archive it for long-term fraud proofs.
The key trade-off: If your priority is minimizing operational cost for high-throughput Layer 2 rollups and you have a robust data archival strategy, choose Blobs. If you prioritize permanent, on-chain data availability for standalone smart contracts, oracles (like Chainlink), or high-assurance applications, choose Calldata. For most new L2 deployments (e.g., using OP Stack or Arbitrum Nitro), blobs are the strategic default, while calldata remains essential for hybrid models and core protocol logic where data must live forever on Ethereum.
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