Weighing the choice of removing or keeping OP_RETURN data limits in Bitcoin Core 5/9/2025

datalimits.md

From Bitcoin Core version 0.9.0 released:

On OP_RETURN: There was been some confusion and misunderstanding in the community, regarding the OP_RETURN feature in 0.9 and data in the blockchain. This change is not an endorsement of storing data in the blockchain. The OP_RETURN change creates a provably-prunable output, to avoid data storage schemes – some of which were already deployed – that were storing arbitrary data such as images as forever-unspendable TX outputs, bloating bitcoin's UTXO database.Storing arbitrary data in the blockchain is still a bad idea; it is less costly and far more efficient to store non-currency data elsewhere.

Pros

Limits the delays of block propagation

OP_RETURN data remains prunable

Less stress on the UTXO set, which causes the blockchain to bloat in size

Mitigates mining centralization

The closest solution without consensus change

Cons

The code to limit OP_RETURN data has been removed

The option for node operations to set limits is gone

Footnotes

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_{Last updated - 5/9/2025 (Blockheight: 895984) Feel free to leave more info.}