Dashboard · VantagePlanned

Ethereum Blob Fees and Blobs per Block vs Target

How many blobs are used per block versus the target, and what does a blob cost right now?

Blob base fee and blobs per block against the target and maximum, with the rollups that buy blob space, block by block on Ethereum.

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Blueprint

What the dashboard will show.

The dashboard as it will open in Vantage. Each figure is named here and arrives with its receipt; until its data is published, its place stays empty.

  • Period

Now

The latest blob price and how full recent blocks were.

Blob base fee

gwei

The blob base fee of the latest finalized block, computed from its excess_blob_gas.

Figuregas_blocksAwaiting data

Cost of one blob

USD

The blob base fee times the blob gas in one blob at the latest finalized block, in ETH and USD.

Figuregas_blocksAwaiting data

Blobs in the latest block

blobs

Blobs carried by the latest finalized block, against the target and the maximum in force.

Figuregas_blocksAwaiting data

Blobs per block, last hour

blobs

The average number of blobs per block over the last hour, against the target.

Figuregas_blocksAwaiting data

Blobs per block, recent blocks

blobs

Blobs in each recent block drawn against the target and maximum lines, so stretches above target show where the fee rises.

Bar chartgas_blocksAwaiting data

History

Blob usage and price by day, by rollup and across forks.

Blobs per day

blobs

Blobs posted on the latest complete day, from every block of the day.

Figureblob_usage_dailyAwaiting data

Blocks above target

%

The share of the latest complete day's blocks that carried more blobs than the target.

Figuregas_blocksAwaiting data

Blob base fee by day

gwei

The median and the highest blob base fee of each day, with each fork marked.

Line chartblob_usage_dailyAwaiting data

Blobs by rollup by day

blobs

Blobs posted each day, stacked by the rollup that posted them, against the day's target capacity.

Stacked barsblob_usage_dailyAwaiting data

Period
Last day, week, month or year
About

What it answers, and for whom.

Blobs are the data space rollups buy on Ethereum to publish their batches. Each block can carry up to a maximum number of blobs, and the blob base fee rises when blocks carry more than the target and falls when they carry fewer. This dashboard reads both from every block header, so the price and the usage are exact.

Since the Fusaka upgrade, blob capacity can be raised through small blob-parameter-only forks, and the blob base fee is held up by a reserve price tied to the execution base fee. The dashboard marks each fork on its charts, with the target and maximum in force at every block.

Use it to see whether blob space is scarce, what a rollup pays to post a blob and which rollups use the most. Every figure is pinned to its block, with the header fields it came from.

Method

How it will be measured.

Every figure will be read at a block, kept with its source and its exact read, and open a receipt anyone can re-check.

How receipts work →
  1. Blobs per block are blob_gas_used from each header divided by the blob gas in one blob; the target and maximum come from the fork schedule in force at that block.
  2. The blob base fee is computed from the header's excess_blob_gas with the active fork's update fraction, and checked against blobGasPrice in the receipts of type-3 transactions in the same block.
  3. Since Fusaka, EIP-7918 stops the blob base fee from falling while it sits below a reserve price tied to base_fee_per_gas; the dashboard marks the blocks where that rule applied.
  4. Blob transactions are attributed to rollups by their sender (the batcher) and destination (the batch inbox), from a maintained registry; unknown senders are shown as other.
  5. The cost of one blob is the blob base fee times the blob gas in one blob, converted to USD with the Chainlink ETH/USD feed at the same block.

The data it needs

Read from chain state and history

  • gas_blocksTo buildGas per blockBase fee, priority fee percentiles, gas used and gas limit for each block on fee-market chains, for a near-live gas tracker.
  • blob_usage_dailyTo buildBlob usage and blob feesEIP-4844 blobs posted per day, blob gas used, blob base fee, and the rollup that posted them.
  • native_prices_dailyTo buildOracle prices by dayReference prices of major assets read from on-chain oracle feeds (Chainlink latestRoundData) at each day's last block, with each round's update time.
  • blob_gas_used and excess_blob_gas from every Ethereum block header
  • Type-3 transactions: blob_versioned_hashes counts, and blobGasPrice and blobGasUsed from their receipts
  • The fork schedule: activation epochs with each fork's blob target, maximum and update fraction
  • A registry of rollup batcher and batch inbox addresses
  • Chainlink ETH/USD at the same block for USD values
Questions

Questions people ask.

What is a blob on Ethereum?

A blob is a large, fixed-size piece of data attached to a type-3 transaction, introduced by EIP-4844. Rollups use blobs to publish their batches. Blobs have their own fee market, and consensus nodes keep blob data for a limited period rather than forever, which is why blob space usually costs far less than calldata.

How is the blob base fee set?

Like the execution base fee, it follows demand: each block that carries more blobs than the target raises it, and each that carries fewer lowers it, through a running excess_blob_gas counter in the block header. It is paid in ETH and burned.

What are the blob target and maximum?

The target is the number of blobs per block that the fee market aims for; the maximum is the most a block may carry. Both are protocol parameters, and since Fusaka they can be raised by blob-parameter-only forks without a full network upgrade.

What did PeerDAS change?

PeerDAS (EIP-7594) lets nodes confirm that blob data is available by sampling pieces of it instead of downloading every blob. That lowers the bandwidth each node needs, which is what allows the blob target and maximum to rise.

Why are blob fees sometimes close to zero?

When blocks carry fewer blobs than the target for a long stretch, the blob base fee falls toward its minimum. Since Fusaka the reserve price stops it from sinking far below a level tied to the execution base fee, so rollups still pay something for the data they post.

Blob
A fixed-size data attachment to a type-3 transaction, kept by consensus nodes for a limited time and used by rollups to publish batches.
Blob gas
The separate unit blobs are priced in, with its own base fee, apart from the gas that pays for execution.
Excess blob gas
A block header field that tracks blob usage above the target over time; the blob base fee is computed from it.
BPO fork
A blob-parameter-only fork: a small network upgrade that changes only the blob target, the maximum and the fee update fraction.

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