Bitcoin Core v30 upgrade is out now, and it has sparked attention from node operators, miners, and enthusiasts for the OP_RETURN feature changes, among many others. The new release has decreased transaction costs and worked on the wallet system.

Still, the most talked about change is the OP_RETURN data limit that has been changed to 100,000 bytes from the default 83 byte limit. This major expansion in data carrier limits has brought back up the long-standing questions of whether Bitcoin is a digital currency or a data platform.

What is the OP_RETURN Data Limit?

OP_RETURN is a script in the Bitcoin blockchain that helps in embedding arbitrary data into a transaction, much like leaving a note. Arbitrary data can be anything, but since it was limited to 83 bytes, it contained just short hashtags or small metadata strings. These are designed not to interfere with the UTXO set, which prevents unwanted data bloating in the network and thereby maintains efficiency. These are used for stamping digital certificates, recording hashes, and adding external data into the blockchain.

OP_RETURN data limit was set to 83 bytes before the update; it is set to 100k bytes now. The data limit prevents unwanted data from being embedded into the blockchain, spamming, and keeps the network efficient.

It also prevents hiding illegal data in the secure network. The data limit helps Bitcoin maintain it as a payments-focused network rather than a broad data storage platform. 

Major Changes in Bitcoin Core v30  

OP_RETURN Policy Change

The major change in the core v30 update is the OP_RETURN data limit change from 83 bytes to 100k bytes. The significant increase in data limit has raised questions in the community, while some find it a necessary upgrade, others are criticizing it as it moves Bitcoin from a minimalistic and efficient monetary tool to a data layer.

Fee Policy Change

The new update has decreased the transaction costs from ~0.1  sats to ~0.001 sats for a vByte. Miners prioritize transactions that offer higher fee rates. 0.1 sats/vByte was the previous default lower fee one could set, but now it’s possible to keep 0.001 sats. This can help open the door to more microtransactions if the miners are willing to accept these transactions.  

Wallet Upgrade

This is another significant change that could affect miners and users; the legacy Berkeley DB wallet format is being deprecated, and users are required to migrate to more reliable descriptor wallets. Make sure you manually back up your existing wallet before the migration.

Node Interface Change

The UI is being upgraded from Qt5 to Qt6, which includes dark mode for Windows and improved rendering for macOS systems. These changes would have an effect on the user experience for node operators, with more options and defaults. 

Why Data Limit Changes in Bitcoin Core v30 Upgrade?

The data limit of 83 bytes was set long before, and the Bitcoin network has grown significantly. Miners were already bypassing the data limit even before the update by embedding data in Taproot inscriptions and such. This was making data on the blockchain harder to identify and filter.

Providing a larger storage space officially can improve transparency and help in indexing the stored data. Developers also believe that modern hardware can handle larger data bandwidth than before, and it wouldn’t affect the network’s effectiveness, though many believe otherwise.

One other reason that is put forward is the fee-based fairness; if users are willing to pay for more space, they deserve to have it. 

Final Thoughts

The OP_RETURN data limit changes could have an impact on how the Bitcoin network is used. Data storage options were usually done by other networks, like Ethereum. The new change has mixed reactions from the crowd, as some consider it a much-needed change from the old policy, while others criticize the policy for disrupting the minimalistic monetary platform.

The true effect of the update is something that should be tested over time as more users respond to it. Node operators currently can choose their own limits, and the changes help in including all kinds of users. Make sure to back up your wallet and migrate to the new version; node operators and developers have new features to explore.