What changed in ETH blobs?

TLDR

Ethereum recently raised blob capacity. The blob target increased to 14%%CKPROTECTED2%% per block and the maximum blob limit to 21%%CKPROTECTED4%%, expanding data availability for rollups and stabilizing fees as usage grows (report).

1. Change shipped via the second Blob Parameter?Only fork in the Fusaka upgrade cycle (update).
2. Each blob is 128 KB; a block can now hold up to about 2,688 KB of blob data (details).
3. Goal: more blob supply to keep rollup costs steadier and reduce mainnet congestion (overview).

Deep Dive

1. Parameters Raised

The network lifted the blob target from 10 to 14 and the maximum blob limit from 15 to 21. This is a capacity increase inside Ethereums data availability layer designed to meet rising rollup demand (coverage, technical note).

2. What Blobs Are

Blobs are temporary data chunks introduced with EIP?4844 (proto?danksharding) to let layer?2 rollups publish batched data cheaply while inheriting Ethereums security. They are retained on mainnet for roughly 18 days before deletion, which reduces long?term storage burden (background).

3. Effects and Trade?Offs

More blob capacity means rollups can post more data per block (up to about 2.6 MB), improving throughput and helping stabilize mainnet fees as congestion falls. The nuance: if demand grows as fast as supply, fee relief may be muted, and operating near the 21?blob ceiling can stress node bandwidth and storage (impact, risk note).

Conclusion

Ethereum is tuning its blob parameters to scale data availability in small, predictable steps. The latest increase gives rollups more breathing room, which could lower and stabilize user fees. If blob demand accelerates to match capacity, relief could be temporary, so watching blob utilization and L2 fee trends remains essential.