By the end of 2026, the scalability of Bitcoin (BTC) might see further improvements with an anticipated growth in block size to 4 MB.
An analysis conducted by Mempool, a research entity specializing in the Bitcoin ecosystem, suggests that the blockchain’s capacity could witness significant expansion due to an increase in inscription-driven blockchain growth in the coming years.
A section of the analysis mentioned,
“If there is a substantial surge in the utilization of Bitcoin for storing arbitrary data, resulting in consistent 4 MB blocks, the blockchain’s size could hit 1TB by late 2026… We can anticipate a 1 TB blockchain in 2 – 4 years, and 2 TB within 7 – 9 years.”
In comparison, the current block size stands at approximately 1.69 MB per block. Initially limited to 1 MB, the block size was increased post the SegWit (Segregated Witness) upgrade in 2017, which led to a significant network scaling.
Increase in Demand Beyond 1 MB
Following SegWit, there was an upsurge in inscription protocols permitting additional arbitrary data, ranging from text to smart contracts, on the Bitcoin network.
The utilization of block space surpassed the 1 MB threshold, initially set by miners and the network’s default configurations, according to Mempool.
“The median block size saw a rise until block 400,000, where the 1 MB limit was reached, approximately 1.5 years prior to the SegWit activation in block 481,824. Post the introduction of SegWit, the block size gradually grew after an initial, temporary decline.”
The average block size surged from 1.11 MB to 1.69 MB, indicating an increase in transaction data per block.
Mempool suggested that the ongoing trend of extensive adoption of inscription protocols could propel the block size to 4 MB.
Nevertheless, not all Bitcoin core developers share the same enthusiasm about this prospect.
Renowned developer Luke Dash Jr considers ordinals and inscriptions as ‘spam’ and perceives them as an ‘attack’ on the Bitcoin network. Dash has consistently advocated for maintaining the block size below 1 MB to mitigate this ‘attack’ vector.
Despite his proposal to cap the Bitcoin block size at 300 KB by the second half of 2025, the majority of his followers on X (formerly Twitter) did not endorse this plan.
Unlike Bitcoin, Solana boasts a theoretical block size limit of up to 128 MB with significantly higher throughput. This indicates that while Solana offers greater scalability, it is comparatively less decentralized than BTC.
However, the impact of differing opinions within the Bitcoin community regarding block size increments on its adoption and scalability in the future remains uncertain.