Ethereum’s BPO Hard Fork Unleashes 21 Blob Limit - Scaling Breakthrough or Just Another Upgrade?

Ethereum just cranked the dial. The network's second BPO hard fork didn't just tweak settings—it slammed the blob limit up to 21, a move that promises to reshape the economics of Layer 2 scaling.

The Throughput Gambit

This isn't incremental change. Pushing blob capacity to 21 slashes data availability costs for rollups, potentially unlocking a flood of cheaper transactions. It's a direct shot at Ethereum's perennial scaling dilemma, bypassing theoretical debates with a hard-coded solution. Developers get more runway; users get lower fees. The math is brutally simple.

Network Mechanics Under Stress

Watch the validators. Higher blob limits mean heavier payloads—21 blobs per block tests hardware and network resilience. Early metrics will show if the infrastructure bends or holds. Success here doesn't just validate the upgrade; it proves Ethereum can handle its own ambition without centralizing pressure on node operators.

A Finance Guy's Cynical Take

Let's be real—the market will price this as a bullish signal, ignore the technical debt, and then panic-sell at the first minor bug. Traders love a hard fork narrative; it's a volatility catalyst wrapped in jargon. Meanwhile, the actual value accrues slowly, in quieter on-chain metrics most portfolios never track.

Ethereum's scaling story just got a new chapter. Whether it's a footnote or a headline depends entirely on what builders do with that extra space.

TLDR

• Ethereum has completed its second Blob Parameter-Only hard fork to improve scalability and transaction processing.
• The blob limit per block has been raised from 15 to 21 to allow more data storage within each Ethereum block.
• Each blob can hold 128 kilobytes of data which enables blocks to now store up to 2.6 megabytes of temporary data.
• The blob target has been increased from 10 to 14 to help the network process more data more frequently.
• The upgrade aims to improve Layer 2 network efficiency and reduce gas fees during periods of high usage.

Ethereum has completed its second Blob Parameter-Only (BPO) hard fork, raising the blob limit from 15 to 21 this weekend, pushing forward its scalability goals, enhancing throughput, and supporting LAYER 2 growth across the network.

Ethereum Raises Blob Limit, Targets Faster Data Handling

Ethereum executed the second part of the BPO hard fork at 1:01:11 UTC on its mainnet. Developers increased the maximum number of blobs per block from 15 to 21. Each blob holds 128 kilobytes, enabling blocks to carry up to 2.6 megabytes of temporary data.

This adjustment allows ethereum to handle more Layer 2 transactions by allocating more space for off-chain data. Layer 2s batch multiple transactions into blobs before submitting them to the Ethereum base layer. This method improves speed and lowers competition for space.

Developers also raised the blob target from 10 to 14, aiming to use more blobs per block on average. The target reflects the number Ethereum usually tries to maintain in operation. By cautiously increasing this value, the network balances capacity and system demands.

The hard fork aims to keep gas fees stable by reducing network congestion. More blobs mean less competition for mainnet space. As a result, developers expect reduced pressure on base-layer transaction fees.

Upgrade Supports Layer 2 Networks and Security Goals

Ethereum developers said the upgrade strengthens Layer 2 support by improving how data flows from rollups to the mainnet. “Blobs increase data throughput without impacting full node performance,” said a developer during the post-fork review.

With more blobs available, rollups can send more data at once. This reduces delays and improves Layer 2 independence. More reliable rollup performance could help maintain lower gas fees during traffic spikes.

Network operators must meet high hardware standards to process increased blob traffic. Developers are focusing on balancing performance with reliability. They continue to prioritize network security as Ethereum scales further.

The BPO upgrade supports Ethereum’s goal to decentralize activity by enabling smoother off-chain processing. It gives Layer 2s the tools to manage growing demand. At the same time, it maintains secure interaction with the Ethereum base chain.

Developers Consider Raising Gas Limit and Prepare Glamarsterdam Fork

At the Ethereum All Core Developers meeting on December 15, the gas limit was reviewed. Developers discussed increasing it from 60 million to 80 million. That change WOULD allow blocks to include more actions and transactions.

This increase would further enhance Ethereum’s transaction capacity. Developers believe it could help lower gas fees during busy periods. More capacity means fewer users would compete for the same block space.

BPO2 is live! Blob limit is now 21pic.twitter.com/SFB7GjRPwg

— terence (@terencechain) January 7, 2026

Later in 2026, Ethereum plans to launch the Glamarsterdam hard fork. This upgrade will introduce perfect parallel processing. The process enables Ethereum to handle multiple transactions at once.

Glamarsterdam will gradually raise the gas limit up to 200 million. It will also include Block Access Lists under EIP-7928. These lists help nodes identify data dependencies more efficiently.

Perfect parallelism will reduce sequential processing bottlenecks. It will let Ethereum manage growing activity without slowing block production. The feature will push Ethereum closer to its scalability objectives.

With the BPO fork completed and Glamarsterdam underway, Ethereum continues to pursue broader throughput and processing improvements. Developers remain focused on performance upgrades through planned protocol changes.