The Bitcoin Core development team has merged a controversial update to the OP_RETURN policy, slated for release in October 2025.
Proposed by Bitcoin pioneer Peter Todd and supported by Chaincode Labs, this change removes the longstanding 80-byte limit on data storage in Bitcoin transactions while allowing unlimited data inclusion.It is highlighted by developer Greg Sanders on GitHub.
The update aims to enhance efficiency, particularly following the 2024 ordinals inscriptions craze, which popularized data storage on the blockchain. However, the decision has ignited a firestorm within the crypto community.
“It doesn’t make economic sense to use OP_Return for large amounts of data,” Peter Todd said in a reply, adding, “Witness space is cheaper. And we already consider transactions up to 100KvB/400KB to be standard.”
It doesn’t make economic sense to use OP_Return for large amounts of data. Witness space is cheaper. And we already consider transactions up to 100KvB/400KB to be standard.
— Peter Todd (@peterktodd) June 9, 2025
Critics, including prominent Bitcoiner Samson Mow, argue that the change lacks consensus and could increase operational costs for nodes, potentially centralizing mining power—a concern echoed by Core developer Luke Dashjr, who has long warned about mining centralization risks.
Experts like Jimmy Song say that the change would bring more garbage on the chain.
OP_RETURN outputs greater than 83 bytes will increase significantly, UTXO bloat will keep getting worse and there will be more garbage on chain.
This is going to age like a bad tattoo. pic.twitter.com/hUTpg8a5NM
— Jimmy Song (송재준) (@jimmysong) June 9, 2025
“OP_RETURN outputs greater than 83 bytes will increase significantly, UTXO bloat will keep getting worse and there will be more garbage on the chain.” he said.
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