A golden Bitcoin coin with two translucent overlapping rings, one orange and one blue, interlaced around the same coin
Original illustration generated with AI (Adobe Firefly) — not representative of real data.

Bitcoin Core vs. Knots: The Differences and the Debate, Explained

NodeWitness Team 5 min read

The short answer: Bitcoin Core and Bitcoin Knots enforce the same consensus rules, so they follow the same chain and accept the same blocks. The difference is relay policy: since Core v30 (October 2025) Core relays OP_RETURN outputs up to 100,000 bytes by default, while Knots keeps a much stricter default filter. On October 7, 2026, Knots ran on 16.5% of reachable nodes per Bitnodes. For your funds' security, the choice doesn't matter; for which unconfirmed transactions your node helps relay, it does.

Bitcoin Knots went from roughly 2% of public nodes in January 2025 to over 20% by September, with at least one report citing a peak near 25%. That's the largest client diversity shift outside a hard fork event in Bitcoin's recent history, and the chain never split. If a change that size didn't fork anything, the actual mechanism behind it is worth understanding before deciding whether it should change what you run.

Where it stands now: on October 7, 2026, the Bitnodes crawler counted 4,111 Knots nodes out of 24,881 reachable ones, or 16.5%. That's below the 2025 peak, but still about one node in six, a full year after the Core v30 change that triggered the move. For each client's current defaults, read from the source code, see Core vs. Knots, checked against the code. Only 80 of them run the RDTS build tied to the BIP-110 fork; the rest follow exactly the same chain as Core. One caveat on any of these numbers: crawlers only see nodes that accept incoming connections, so nodes behind a firewall go uncounted on both sides.

The key difference: consensus rules vs. relay policy

This has nothing to do with fund security, and it's a different topic from address reuse or anything else we've covered on wallet privacy — it's about how one specific type of data propagates across the network, not about who can see your transactions.

Two layers get conflated constantly in this debate:

  • Consensus rules decide what block is valid. Identical in Core and Knots. Neither rejects blocks mined under the other.
  • Relay policy is each node's local preference for which unconfirmed transactions it helps propagate before they're mined. This is what actually differs.

A Knots node still accepts and validates blocks containing large OP_RETURN payloads — consensus allows it — it just won't relay those specific unconfirmed transactions by default. That's dissent made visible, not an effective veto, unless the filtering side becomes a supermajority.

Diagram distinguishing consensus rules, identical in Bitcoin Core and Bitcoin Knots, from relay policy, which differs by default between the two
Original diagram: the distinction that explains why this dispute never split the chain.

What actually changed in Core v30

October 2025's Core release raised the default -datacarriersize limit for OP_RETURN outputs from 83 bytes to 100,000 bytes, meaning Core nodes now relay much larger arbitrary-data payloads by default than before. Knots, a patch set maintained by Luke Dashjr on top of Core, kept the tighter filtering.

A Knots node relaying a large OP_RETURN transaction anyway isn't a bug in the filtering — it just means enough of the rest of the network chose to propagate it. The filter is a preference, not a wall.

The actual disagreement underneath the technical detail

Strip away the mechanics and this is a fight about what Bitcoin is for. The case for Core's direction: neutrality is the point — the network should relay any valid transaction, full stop, without software deciding which uses count as legitimate. The case for Knots' stance: letting non-monetary data storage (inscriptions, tokens, images) grow unfiltered pushes fees up for people who just want to send value, and invites regulatory scrutiny the ecosystem doesn't need.

Neither position is "official." Bitcoin has no central authority to settle this kind of argument, which is exactly why both pieces of software can coexist without breaking anything.

So, should you switch?

If you're not running your own node, this changes nothing for you either way — your coins are equally safe regardless of which software wins mindshare this year. If you do run one, the choice is about which relay policy you want to back with your own bandwidth, not a security tradeoff: both implementations validate the chain identically, and neither one puts your funds at risk. Pick the one whose philosophy you actually agree with, and don't lose sleep over the rest of the network (83% of reachable nodes run Core as of October 2026) running something else. That's a different kind of disagreement from BIP-110: there, picking a side actually mattered, because the activation client enforced different consensus rules than Core, not just a different relay policy — the same class of decision still hanging over unresolved proposals like the quantum threat.

Bitcoin's issuance keeps moving on a schedule that's already fixed — you can follow the live countdown to block 1,000,000 and to 96% of the supply already issued.

Curious how hashrate actually splits across mining pools, calculated from our own node? Check Network & Mining.

Sources

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Last updated: October 7, 2026