GlossaryAdvanced
Blob (Ethereum)
A large data packet Ethereum introduced to let Layer 2 rollups post data more cheaply.
A blob is a large packet of data that Ethereum introduced (via the EIP-4844 upgrade) as a distinct, cheaper way for Layer 2 rollups to post their transaction data back to Ethereum's base layer, compared to including that data as regular, more expensive transaction calldata.
Blob data is automatically deleted from Ethereum nodes after a set retention period, since it's needed for a limited verification window rather than permanent storage.
Examples
- Rollups posting data as blobs pay substantially less than they would posting the same data as regular calldata.
- Blob data is retained by Ethereum nodes only temporarily, not indefinitely.