Key Points
- Bitcoin’s block size could potentially expand to 4 MB by 2026, according to Mempool research.
- The growth is expected to be driven by an increase in inscription protocols.
The scalability of Bitcoin could potentially be enhanced by the end of 2026, with the block size projected to grow to 4 MB.
Block Size Growth Driven by Inscriptions
This prediction comes from a recent report by Mempool, a research firm specialising in the Bitcoin ecosystem. They suggest that growth driven by inscriptions on the blockchain could increase significantly in the coming years.
The report states, “If we see massive growth in the use of Bitcoin to store arbitrary data (resulting in consistent 4 MB blocks) the blockchain would reach 1TB by late 2026…We should expect a 1 TB blockchain after 2 – 4 years, and 2 TB in 7 – 9 years time.”
Currently, the block size is approximately 1.69 MB per block, having been initially capped at 1 MB before the SegWit (Segregated Witness) upgrade in 2017, which significantly scaled the network.
Demand Beyond 1 MB
Following the SegWit upgrade, there was an increase in inscription protocols allowing for additional arbitrary data, such as texts and smart contracts, on the Bitcoin network. This led to a surge in demand for block space beyond the 1 MB limit, set by miners and the network’s default settings.
Mempool suggests that this trend of increased adoption of inscription protocols could potentially expand the block size to 4 MB. However, not all Bitcoin core developers are in agreement with this outlook.
Luke Dash Jr, a prominent Bitcoin developer, views ordinals and inscriptions as ‘spam’ and an ‘attack’ on the Bitcoin network. He has advocated for capping the block size below 1 MB to prevent this perceived ‘attack’. Despite this, many of his followers on X (formerly Twitter) did not support his proposal to cap Bitcoin’s block size at 300 KB in the second half of 2025.
In contrast to Bitcoin, Solana’s theoretical block size limit can reach 128 MB at a much higher throughput. This suggests that Solana is more scalable but less decentralized than Bitcoin. The impact of these divergent views on block size increment on Bitcoin’s future adoption and scalability remains to be seen.