This can be seen as a victory for progressives over conservatives in the Bitcoin community regarding increasing the network's utility.
The next Bitcoin Core update will raise the OP_RETURN limit. Image: Bitcoin News
According to the announcement posted late on 09/06/2025, developer Gloria Zhao said that the Bitcoin Core v30 software version to be deployed in October will have an option for node operators to customize the OP_RETURN limit from the current 80 bytes to 4 MB.
Ms. Zhao argued that Bitcoin Core is just a node software for the community, which can be copied and modified by anyone, so it is natural that the product should reflect all the desires of the Bitcoin ecosystem.
Therefore, Bitcoin Core v30 will increase the default OP_RETURN limit to 4 MB, but will still allow users to set the old parameters if desired.
I posted a full writeup for the #32406 merge decision on the PR.
— gloria (@glozow) June 9, 2025
These changes go into effect in v30, which is scheduled for release in October.
The PR changes the defalt value of -datacarriersize. You will still be able to use -datacarrier and -datacarriersize options in v30,…
OP_RETURN has been a controversial topic in the Bitcoin community for months. On the supporting side, veteran names like Peter Todd and Jameson Lopp argue that removing the limit will help the network operate more transparently, be more consistent between nodes, and accurately reflect the current reality, where most Miners no longer adhere to the old limit. In contrast, the opposing side led by Luke Dashjr and Jason Hughes is concerned that this change will facilitate spam behavior, cause an uncontrolled blockchain expansion, and increase the burden on operating nodes.
The proposal to increase the OP_RETURN size emerged in 2024 along with the Ordinals – Inscription trend, promoted by participants because it helps Bitcoin blocks to contain more data, adding new use cases instead of just storing transaction information as usual.
The Bitcoin Core v30 version raising the default OP_RETURN limit can be seen as a victory for the progressive side over the conservative group, as most node operators will use the software's default settings and are unlikely to spend effort adjusting unless they really want to.
However, the conservative side warns that this will encourage users to switch to alternative node software like Knots, which can be seen as the market share of this client has increased from 2% to 11% since the OP_RETURN debate began.
You ignore community consensus, you lose trust. Since Bitcoin Core's OP_RETURN fiasco, @BitcoinKnots has surged from 2% to 11% of nodes. That's what happens when contentious changes are rammed through. Actions → consequences pic.twitter.com/JBHX2zgXQO
— privacymatters21m (@privacymatter21) June 9, 2025
Compiled by Coin68
