Key Points:
Bitcoin Core v30 raises OP_RETURN limit to 100,000 bytes, aligning policy with miner behavior.
Critics fear larger data use may increase chain bloat and move Bitcoin away from monetary use.
Developers argue new limit supports prunable data, reducing UTXO strain and promoting mempool neutrality.
Bitcoin Core developers have confirmed that version 30 of the reference client will remove the long-standing 83-byte default cap on OP_RETURN data. The update is scheduled for release in October and will increase the maximum OP_RETURN payload size to 100,000 bytes. This brings the effective ceiling in line with broader constraints such as the 400 KB standard transaction size and the 4 MB block weight limit.
The OP_RETURN function allows users to embed data directly into Bitcoin transactions. The removal of the previous limit means developers and users can now insert larger amounts of data, with enforcement driven more by existing technical limits than predefined policy rules.
Policy Shift Fuels Heated Discussion Among Developers
The decision has triggered renewed debate across the Bitcoin development community. Critics argue that loosening restrictions on OP_RETURN data could lead to an uptick in spam-like transactions and make the network more vulnerable to inefficient data use. Others are concerned it shifts Bitcoin away from its role as a monetary protocol.
Veteran developer Luke Dashjr remains opposed, encouraging users to either delay upgrading or switch to other clients like Bitcoin Knots. He expressed concern that larger OP_RETURN entries would cause unnecessary network clutter. Bitcoin educator Jimmy Song commented that this change “will age like a bad tattoo,” citing fears of chain bloat and resource misuse.
Developers Highlight Benefits of Reduced Friction
Supporters of the change maintain that increasing the limit aligns Bitcoin Core’s policy with actual miner behavior. They argue that the prior 83-byte cap led users to find workarounds, including methods that increased the burden on the unspent transaction output (UTXO) set or required off-mempool miner deals.
Developer Gloria Zhao, who merged the code, noted the decision addresses imbalances in how different types of on-chain data are treated.
“The goal is to allow prunable data without pushing users to adopt less efficient, more harmful methods,” Zhao explained.
Greg Sanders, who authored the pull request, added that the update simplifies default behavior across nodes and contributes to a cleaner UTXO set.
Open Governance, Continued Debate, and Optional Limits
In anticipation of criticism, Bitcoin Core contributors published an open letter stating the network must remain permissionless and censorship-resistant. The letter emphasized that accepting non-financial data does not mean endorsing it, but reflects Bitcoin’s open design.
Zhao also addressed governance concerns, writing,
“If contributors ever abandon core values to appease public pressure or corporations, the community will switch to better implementations.”
While the new settings will become the default in Bitcoin Core v30, users will still be able to enforce stricter limits using command-line options. These options remain available but are marked as deprecated, meaning they may be removed in future updates.
DISCLAIMER: The information on this website is provided as general market commentary and does not constitute investment advice. We encourage you to do your own research before investing.
