# Blob fees: a separate fee market for rollup data Blob-carrying Ethereum transactions pay a separate blob-gas charge in addition to execution gas. EIP-4844 introduced a demand-sensitive blob base fee and a blob fee cap. Rollups can use blobs for data publication, but their user fees also depend on execution, batching and the rollup’s own accounting rules. Evidence: [Shard Blob Transactions](https://eips.ethereum.org/EIPS/eip-4844); [OP Stack transaction fees](https://docs.optimism.io/stack/transactions/fees) Canonical: https://degreesofsatoshi.com/encyclopedia/ethereum-blob-fees/ Published: 2026-10-02 Substantively modified: 2026-10-02 Independently verified by an automated reviewer: 2026-10-02T18:12:41.505Z Data current through: 2026-10-02 AI-assisted research and drafting with a separate automated source-verification pass; no external expert or named human review is implied. ## Key facts - **Separate meter:** Blob gas and ordinary execution gas use distinct accounting. ([Shard Blob Transactions](https://eips.ethereum.org/EIPS/eip-4844)) - **Fee cap:** The transaction’s blob fee cap must cover the applicable blob base fee. ([Shard Blob Transactions](https://eips.ethereum.org/EIPS/eip-4844)) - **Failure:** The specified blob charge is burned and not refunded when execution fails. ([Shard Blob Transactions](https://eips.ethereum.org/EIPS/eip-4844)) ## Identify the component being calculated The specified blob fee multiplies total blob gas by the blob base fee. Total blob gas depends on the number of blobs and the active per-blob gas rule. The ordinary execution fee is calculated separately. A transaction’s execution receipt fields alone may therefore omit part of the total amount paid. Evidence: [Shard Blob Transactions](https://eips.ethereum.org/EIPS/eip-4844) ## Keep fork-specific constants dated EIP-4844 documents the original mechanism and parameters. Later network upgrades can change capacity targets, limits and adjustment parameters, so an old table should not be presented as a current network configuration. This article explains the mechanism without offering a live fee quote. A reproducible fee observation needs a chain, block and the active fork rules. Evidence: [Shard Blob Transactions](https://eips.ethereum.org/EIPS/eip-4844); [Blob throughput increase](https://eips.ethereum.org/EIPS/eip-7691) ## Data cost and a user quote are different levels A rollup can batch many users’ data into its publication process. How those costs are allocated, alongside execution and other charges, depends on the rollup. Blob data is handled through the consensus data-availability mechanism; it is not ordinary permanent EVM storage. Cheaper publication does not eliminate the need to understand retention and settlement. Evidence: [Shard Blob Transactions](https://eips.ethereum.org/EIPS/eip-4844); [OP Stack transaction fees](https://docs.optimism.io/stack/transactions/fees) ## Questions ### Can a contract read all blob contents directly as normal calldata? No. EIP-4844 separates blob data from ordinary EVM-accessible calldata. BLOBHASH exposes versioned hashes, and the point-evaluation precompile can verify supplied KZG proofs against commitments. Evidence: [Shard Blob Transactions](https://eips.ethereum.org/EIPS/eip-4844) ## Claims and scope ### ethereum-blob-fees-quick-answer Blob-carrying Ethereum transactions pay a separate blob-gas charge in addition to execution gas. EIP-4844 introduced a demand-sensitive blob base fee and a blob fee cap. Rollups can use blobs for data publication, but their user fees also depend on execution, batching and the rollup’s own accounting rules. Scope: {"collection":"ethereum","dataAsOf":"2026-10-02","blockHeight":null} ### ethereum-blob-fees-fact-separate-meter Separate meter: Blob gas and ordinary execution gas use distinct accounting. Scope: {"collection":"ethereum","dataAsOf":"2026-10-02","blockHeight":null} ### ethereum-blob-fees-fact-fee-cap Fee cap: The transaction’s blob fee cap must cover the applicable blob base fee. Scope: {"collection":"ethereum","dataAsOf":"2026-10-02","blockHeight":null} ### ethereum-blob-fees-fact-failure Failure: The specified blob charge is burned and not refunded when execution fails. Scope: {"collection":"ethereum","dataAsOf":"2026-10-02","blockHeight":null} ## Sources - [Shard Blob Transactions](https://eips.ethereum.org/EIPS/eip-4844) — Ethereum Improvement Proposals. Blob commitments, separate blob-gas fee calculations and temporary data availability. Locator: Gas accounting; Opcode to get versioned hashes; Point evaluation precompile; Consensus layer validation. Retrieved: 2026-10-02T17:03:42.506Z. - [OP Stack transaction fees](https://docs.optimism.io/stack/transactions/fees) — Optimism. Rollup execution, data-publication and operator fee components depend on active network upgrades. Locator: Gas fee components; Execution gas fee; L1 data fee; Operator fee. Retrieved: 2026-10-02T17:55:17.901Z. - [Blob throughput increase](https://eips.ethereum.org/EIPS/eip-7691) — Ethereum Improvement Proposals. A later fork changes blob targets and limits relative to EIP-4844. Locator: Specification; Rationale. Retrieved: 2026-10-02T17:55:17.000Z. ## Revision history - 2026-10-02: First publication after primary-source research and independent automated verification. ## Cite this entry Degrees of Satoshi editorial project. “Blob fees: a separate fee market for rollup data.” Published 2026-10-02; updated 2026-10-02. https://degreesofsatoshi.com/encyclopedia/ethereum-blob-fees/