Bitcoin Core’s Version 30 Sparks Debate with OP_RETURN Limit Boost

The Bitcoin Core development team has made headlines two days in a row, confirming that version 30 of the software, slated for release in October 2025, will increase the default OP_RETURN data limit from 80 bytes to nearly 4 megabytes (mb).

This change represents a dramatic expansion of Bitcoin’s on-chain data capacity. It also marks a decisive win for the reformist developers led by Antoine Poinsot in a long-running internal dispute.

Bitcoin Core 30 Expands OP_RETURN Limit, Igniting Community Backlash

OP_RETURN, the instruction to embed data within Bitcoin transactions, has traditionally been tightly restricted to prevent blockchain bloat.

The newly approved change unlocks massive capacity for storing crypto inscriptions and other on-chain data directly through Bitcoin Core, without requiring protocol workarounds.

Supporters argue that this could improve the infrastructure for Bitcoin Layer 2 solutions, decentralized identity systems, and BTC-anchored Web3 projects.

Based on feedback on X (Twitter), it is controversial, with the increase reigniting deep tensions within the Bitcoin community. Specifically, there is disagreement between those favoring innovation and others prioritizing minimalism and node decentralization.

Bitcoin advocate Jimmy Song criticized the update, stating it would worsen UTXO (Unspent Transaction Output) bloat by enabling more on-chain spam.

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

Meanwhile, other users echoed concerns about centralization and censorship resistance.

“You ignore community consensus, you lose trust. Since Bitcoin Core’s OP_RETURN fiasco, Bitcoin Knots has surged from 2% to 11% of nodes. That’s what happens when contentious changes are rammed through,” the user wrote.

The ideological divide comes as users criticize what they see as an agenda driven by large development sponsors.

“Bitcoin Core (Chaincode/Spiral) just merged removal of the OP_RETURN filter to be released later this year in v30. This marks the end of ‘Bitcoin Core’ being the trusted reference client if it wasn’t already clear. It has been overtaken by shitcoin enablers,” another user posted.

Ideological divide between for OP_RETURN. Source: CKB on X

Victory for Reformists, but Critics Warn of Bloat, Centralization, and Trust Erosion

The reformist push for a larger OP_RETURN has been brewing since Peter Todd’s proposal in late April, which caused a rift between developers and the broader Bitcoin community.

Todd warned of the risks of long-term centralization and questioned whether Bitcoin’s core values were being sacrificed for short-term flexibility.

According to Peter Todd, formalizing higher limits would reflect existing practices and benefit use cases like sidechains and cross-chain bridges.

“The restrictions are easily bypassed by direct substitution and forks of Bitcoin Core,” Todd noted in his GitHub comments.

Peter Todd’s proposal to remove arbitrary limits on OP_Return. Source:  GitHub

Supporters of the OP_RETURN expansion argue that fears of bloat and spam are overblown. They suggest that with appropriate fee markets and filtering mechanisms, Bitcoin can remain secure while enabling broader use cases.

Further, some believe this change is necessary to maintain Bitcoin’s relevance in an increasingly competitive market.

Notably, this development arrives barely a day after Bitcoin Core faced backlash over changes to its transaction relay policy.

As BeInCrypto reported, this relay change has already fueled accusations that the project is drifting away from its decentralist roots. Critics perceive the move as limiting accessibility and favoring well-connected nodes.

NACKThe goals of transaction relay listed are basically all wrong. Predicting what will be mined is a centralizing goal. Expecting spam to be mined is defeatism. Helping spam propagate is harmful.This OPED contradicts itself, presenting out of band relay as both negative and…

— Luke Dashjr (@LukeDashjr) June 7, 2025

Despite the backlash, Bitcoin Core remains the most widely used protocol implementation. Recent shifts in node distributions, such as the rise of Bitcoin Knots, signal a growing appetite for alternatives among node operators.

It also accentuates purists’ stance, seeing recent updates diluting Bitcoin’s original design philosophy.

With version 30 on the horizon and ideological battles intensifying, Bitcoin appears to be at another turning point. The transition could define Bitcoin’s path as a programmable, multi-layered technology.