Nazia Saeed
A long-standing restriction on the size of arbitrary data in Bitcoin transactions will be lifted in Bitcoin Core’s next release, a decision stirring both technical and philosophical debate within the community.
On May 5, Bitcoin developers announced via GitHub that Bitcoin Core’s next update will eliminate the 80-byte limit on OP_RETURN outputs and will also allow an unlimited number of such outputs in transactions by default. Bitcoin Core’s next release will, by default, relay and mine transactions whose OP_RETURN outputs exceed 80 bytes and allow any number of these outputs, as per experts.
This change effectively overturns a policy that was originally intended as a gentle signal that block space should be used sparingly for non-payment proof-of-publication data. According to experts, the limit has outlived its usefulness and no longer reflects real-world network behavior.
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The proposal, formally listed as PR 32359, was initiated by Bitcoin pioneer Peter Todd at the request of Chaincode Labs.
Understanding OP_RETURN and Its Role
OP_RETURN is a Bitcoin script opcode that allows small chunks of non-financial data to be embedded within a transaction. Unlike typical outputs, these are non-spendable, meaning they do not contribute to the UTXO (unspent transaction output) set—avoiding long-term blockchain bloat.
Interest in OP_RETURN surged during the ordinals inscription boom in early 2024, where users embedded digital artifacts into Bitcoin’s blockchain, showcasing its capacity beyond pure payments.
Despite the original cap, users had already found workarounds to include larger data—often by spoofing output addresses in ways that ironically impose more strain on the network. Additionally, some mining pools were already choosing to ignore the 80-byte limit, undercutting its intended deterrent effect.
Experts argues that removing the cap brings several technical benefits, including:
- A cleaner and more manageable UTXO set.
- Greater protocol consistency across nodes.
- A better match with how Bitcoin is currently being used.
Backlash and Governance Questions
Critics have raised flags over the lack of broad consensus prior to the implementation, arguing that such a significant change should not be introduced unilaterally.
Some in the community also questioned whether the shift deprioritizes Bitcoin’s role as sound money and raised concerns about possible undisclosed conflicts of interest surrounding the proposal.
While the technical rationale for the change appears robust, the broader conversation reveals a persistent tension within the Bitcoin community—balancing innovation and adaptability with ideological purity and conservative protocol stewardship.
As the update rolls out, whether users accept, reject or fork away from the change may shape how future upgrades to Bitcoin Core are proposed and received.
