In October, Bitcoin Core is expected to release version v30, which will by default remove the size limit on OP_RETURN data. The only constraint will be the standard 4 MB block size.
Currently, OP_RETURN is limited to 83 bytes. Bitcoin developer Peter Todd proposed lifting this cap, sparking a fierce debate within the community. Critics warn this may lead to blockchain bloat from non-financial transactions, while supporters argue that true decentralization requires freedom — even when not everyone agrees with the use case.
The -datacarriersize argument will still be available for users who wish to set a custom limit, but it will be marked as deprecated.
In an open letter published in June, the Bitcoin Core team explained that censorship resistance is a core principle of Bitcoin. Limiting how data is used — even if it’s non-financial — contradicts that ethos.
“This does not mean we endorse arbitrary data storage,” the team wrote, “but rather acknowledge that a censorship-resistant systеm will naturally permit use cases not everyone agrees with.”
Not everyone was convinced. Dennis Porter, co-founder of the Satoshi Action Fund, announced he would no longer support Bitcoin Core financially. Ocean mining pool’s VP accused the dev team of acting like a corporation and warned of reputational damage to Bitcoin.
Bitcoin advocate Jimmy Song noted the network would now see an increase in data “junk,” potentially harming long-term efficiency and user trust.
