- Bitcoin developers have confirmed they have removed the 80‑byte default limit on OP_RETURN data
- They have aligned relay policy with miners by allowing OP_RETURN outputs up to block‑size limits, up to 4MB
- They have deprecated config flags like ‘datacarrier’, sparking debate over decentralization and spam
Bitcoin Core developers have officially confirmed that the longstanding 80‑byte cap on OP_RETURN outputs will be lifted in the upcoming version 30 release, aligning relay policy with miners and removing an artificial constraint. This means larger metadata transactions, even nearing the 4MB block size, will now be relayed and mined by default, while previously optional configuration flags are being deprecated. The move has ignited debate regarding network spam, blockchain bloat, and the future of Bitcoin’s ideological underpinnings.
Proponents Say 80-Byte Cap is Pointless
The 80‑byte threshold was originally intended as a harm‑reduction measure to deter non‑payment data, but over time it has become counterproductive, pushing users toward more harmful workarounds that bloat the critical UTXO set. Greg Sanders, a Blockstream engineer who is the author of the proposal, argued on GitHub, “Large‑data inscriptions are happening regardless… The cap merely channels them into more opaque forms that cause damage to the network.” He added the change delivers “a cleaner UTXO set and more consistent default behavior,” while Bitcoin luminary Peter Todd noted the cap has been routinely bypassed, rendering it ineffective.
This change affects the rules for how transactions are shared across the network (known as standardness), but it doesn’t change the core rules that every Bitcoin node must follow (consensus); blocks are still limited to around 4 MB in size, but now, transactions with OP_RETURN data longer than 80 bytes will be accepted and passed along by default, unless node operators manually choose to enforce a smaller limit, using settings that are now officially being phased out. Conservative node operators may continue enforcing smaller caps, but most are expected to stick with defaults.
The Debate: Innovation vs. Bloat
Opponents led by Luke Dashjr, maintainer of Bitcoin Knots, have warned that the move is “utter insanity,” fearing network spam and mission drift. Bitcoin maximalists like Jimmy Song tweeted that the decision was going to “age like a bad tattoo…” adding that “UTXO bloat will keep getting worse.” Samson Mow encouraged users to stay on Core 29 or switch to Bitcoin Knots rather than upgrade to Core 30 to avoid the change.
This shift marks a broader philosophical battle within Bitcoin’s governance: whether to evolve as programmable money infrastructure or preserve staunch minimalism. Supporters believe richer OP_RETURN usage unlocks innovations from timestamping and cross‑chain protocols to decentralized identities and Runes, while opponents see it as erosion of design intent. With v30 due in October and the datacarrier config flags fading away, the community now faces a clear fork in the path between expanded utility or defensive preservation.
