Ethereum blobs have a guarantee of around 18 days, but they don’t necessarily disappear after that. Since Dencun, March 13, 2024, second-layer networks have published their data there at lower cost. On October 27, 2026, the Blobscan archive still indicated three storage locations for the first blob it identified, published on March 13, 2024.
In brief
- 4,096 epochs: this is the minimum duration, approximately 18 days, during which the network must provide a blob.
- 128 KiB: this is the raw size of a blob, or 4,096 elements of 32 bytes.
- 8,745 bytes: according to Blobscan, the first blob, published on March 13, 2024, did not use more.
- 21 blobs: this is the maximum per block since January 7, 2026, compared to 6 at their launch.
Ethereum Blobs: separate data in each block
Second-layer networks, like Base or Arbitrum, bring together thousands of operations. They then publish the data on Ethereum which allows them to be verified. Before March 2024, this data most often passed through the “calldata” of transactions. This field remains stored in the channel history forever.
L’EIP-4844activated by Dencun, created another path. A type 3 transaction now carries blobs, data packets that circulate in the consensus layer. Smart contracts cannot read their content. They only access a cryptographic fingerprint of each blob, called a “versioned hash”.
Blobs also have their own cost market, distinct from conventional gas. Their price depends first on the demand for blobs. Since Fusaka, however, it cannot go below an execution fee floor, under EIP-7918.
18 days: a service obligation, not a deletion date
EIP-4844 sets the window to 4096 epochs. An epoch has 32 slots of 12 seconds. The 4,096 epochs therefore represent 1,572,864 seconds, approximately 18.2 days. During this period, the nodes must be able to provide the blobs, or from Fusaka their fragments, to whoever requests them. Beyond that, nothing obliges them to keep the Ethereum blobs.
The specification assumes this choice: “it is not expected that blobs should be stored as long as a block’s execution data”. The official Ethereum documentation, however, specifies the scope of this window.
This is a service obligation rather than a removal date.
Ethereum.org, page dedicated to ZK rollups
The same page adds that longer term access depends on archiving services. A blob therefore does not disappear everywhere after 18 days. It simply ceases to be guaranteed by the protocol.
The first blob, found two and a half years later
According to Blobscan, the network’s first blob dates from March 13, 2024 at 1:55 p.m. UTC. It appears in block 19 426 589. On the Etherscan explorer, its transaction remains visible and indicates a type 3 with a blob. This trace belongs to the permanent history of Ethereum.
The content followed a different path. According to theBlobscan archiveaccessed on October 27, 2026, this blob of 131,072 bytes only used 8,745. Blobscan then indicated three storage locations: at Google, on the WeaveVM network and on IPFS. The IPFS link did return a binary file that day.
This test illustrates the Ethereum blob rule. The blob reference remains in the chain, but its content is now only guaranteed by independent archivists. Without them, the fingerprint alone does not allow the data to be reconstructed.
Ethereum Blobs: What’s Left, and Where
Ethereum documentation compares different ways of storing data on the network. The table below is inspired by this.
| Data | Where it is located | After 18 days |
| Type 3 transaction and blob footprints | Channel History | Kept, like any transaction |
| Raw content of a blob | Consensus layer, then possible archives | No longer guaranteed by network nodes |
| Calldata of a classic transaction | Channel History | Preserved, without time limit |
| Status of a smart contract | Chain storage | Kept until modified |
According to this storage strategies pageblobs are therefore used for data to be made available for a time. Rollups use them to make their transactions available for verification, not to archive them.
Ethereum Blobs: PeerDAS increases capacity, not duration
The Fusaka update, activated on December 3, 2025, introduced PeerDAS. With this protocol, an ordinary node no longer downloads all blobs. It checks their availability by sampling, by querying fragments. According to ethereum.org, half of the data is enough to reconstruct the whole.
This saving made it possible to increase the number of blobs per block. L’Fusaka announcement by the Ethereum Foundation provided for two levels. On December 9, 2025, the maximum increased from 9 to 15 blobs per block. On January 7, 2026, it reached 21, with a target of 14.
However, the retention window has not changed. THE Fusaka specifications set the duration for which a node must provide its data fragments at 4,096 epochs. This is the same value as when the blobs arrived.
Since January 7, 2026, each Ethereum block can contain up to 21 blobs. Each remains guaranteed for 4,096 epochs, or approximately 18 days. Their price follows a specific market, governed by execution costs. Our guide to Ethereum transaction fees explains these.
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