The upcoming release of the Bitcoin Core client will by default allow more than 80 bytes of information in OP_RETURN outputs and permit any number of them.
Absolutely non-binding statement, but a read of the Bitcoin Core project as a whole on the subject.https://t.co/3ZngA6ICLr
— instagibbs (@theinstagibbs) May 5, 2025
“The long-standing limit, initially a soft signal to economize block space for non-payment proof-of-publication data, has outlived its usefulness,” noted developer Greg Sanders.
Debates over the restriction on the volume of third-party data published via the OP_RETURN script intensified since late April. Bitcoin developer Peter Todd, who was dubbed the creator of the first cryptocurrency in an HBO documentary, proposed lifting the limit.
Sanders highlighted two main arguments for why the previously set 80-byte limit has become counterproductive and, in many respects, “destructive”:
- it is easily circumvented — miners offer solutions to overcome the limit, and data recording occurs “more or less maliciously,” harming the network;
- it distorts incentives — users resort to “impolite” methods, including fake output keys from the UTXO set.
According to Sanders, Bitcoin Core developers considered three options:
- maintain the limit — deemed ineffective;
- raise the threshold — any value will “age” over time;
- remove the restriction — aligns default policy with actual network practice.
The innovation does not abolish the block limit of 4 million weight units. “Dust” outputs are still rejected, and signature and ancestor/descendant operation limits prevent memory pool growth, the programmer emphasized.
In his view, removing the 80-byte rule offers two main advantages:
- a cleaner UTXO set — data is placed in a single unspendable output rather than being masked in scripts;
- consistent default behavior — nodes relay the same transactions miners want to see, making fees transparent.
“The change affirms that Bitcoin is governed by transparent, minimal rules, not editorial preferences. By discarding a constraint that no longer works, Bitcoin Core maintains policy integrity and allows the fee market to arbitrate competing demands,” Sanders stated.
Earlier, February’s decline in on-chain activity on the Bitcoin network to an annual low was largely attributed by analysts to a drop in OP_RETURN outputs in transactions.