Bitcoin Core’s upcoming v30 release will dramatically increase the OP_RETURN data limit from 80 bytes to 4MB, igniting intense community discussions about Bitcoin’s future direction. Scheduled for October 2025, this technical change enables significantly larger data embedding capabilities, potentially supporting Layer 2 solutions and Web3 applications built on Bitcoin.
The proposal has divided the Bitcoin community. Proponents argue the expanded capacity is essential for innovation, allowing developers to build more complex functionalities directly on-chain. They contend that Bitcoin must evolve to accommodate emerging use cases while maintaining relevance in the competitive blockchain landscape.
Critics, including prominent developer Jimmy Song, warn the change risks triggering blockchain bloat, increased UTXO set growth, and on-chain spam. They caution that larger data storage could compromise Bitcoin’s decentralization by raising node operation costs and deviating from its minimalistic design principles. Song specifically highlighted concerns about long-term network sustainability under heavier data loads.
This controversy has accelerated adoption of alternative node implementations. Bitcoin Knots, a dissenting node software, has seen its network share surge from 2% to 11% as users seek options beyond Bitcoin Core’s development trajectory. The shift reflects growing unease about perceived unilateral decision-making by Bitcoin Core developers.
The debate echoes earlier discussions sparked by developer Peter Todd’s proposal to eliminate OP_RETURN limits entirely. While supporters maintain that fee markets will naturally regulate data usage, opponents emphasize preserving Bitcoin’s foundational values. This fundamental tension between enabling new functionalities and safeguarding network integrity remains unresolved as the October release approaches.