The debate over Bitcoin Op_return is heated as the developers of Bitcoin Core, the most popular node software, will be discarding OP_Return completely in the next release.
The Op_return limit is an 80-byte cap of any amount of data that can be incorporated into a Bitcoin transaction using a special, non-interfering output field.
“The large data inscriptions happen regardless and can be done in a more or less abusive way,” said the core contributor and engineer at Blockstream Greg Sanders, known as “Instagibbs,” in a Github post announcing the removal. “Caps only lead them to more opaque shapes and damage the network.”
This discussion focuses on whether to promote transparency by lifting the 80-byte OP_return limit, simplifying the use of data in Bitcoin, or opening the door to abuse, spam and shifts from Bitcoin’s economic focus.
On Github, Sanders added that by enforcing the cap, they created an evil incentive that drives users to embed data in fake public keys and spendable scripts. Removed the limit, he said, “providing at least two tangible benefits: cleaner UTXO sets and more consistent default behavior.”
Not everyone is sure. Core developer Luke Dashjr has long considered inscriptions and other data storage to be SPAM, and in April 2025 warned that the change was “completely crazy.”
Amidst the controversy, Bitcoin Knot, maintained by DashJR, has expanded adoption, reaching a share of around 5% of all nodes.
Bitcoin Knots, a more customizable fork in Bitcoin Core, appeals to users who have more powerful control over node relays and stores, such as allowing users to reject non-payment transactions like inscriptions.
Prominent thought leaders in the industry like Samson Mow encourage node operators not to upgrade their Bitcoin core version or use knots instead.
Sanders defended the spirit of Bitcoin, the removal of caps that follows the minimum transparent rules.
“By retiring from deterrent forces that no longer deterrent,” he wrote.
But it has not brought much consensus.
“This indicates a fundamental change in the direction of Bitcoin,” one commenter warned on Github.
“This is the biggest mistake the core could make at this point,” added another Github. “I want to say that and become a record.”
Correct: (May 6, 08:14 UTC): Remove “previous” developers from the 7th paragraph.