A fork is how a blockchain protocol is upgraded. A hard fork is a non-backward-compatible change; a soft fork is a backward-compatible one. The fundamental difference: a hard fork relaxes or removes rules, while a soft fork adds or tightens them. This guide explains it.
What a hard fork is
A hard fork is a non-backward-compatible protocol change that requires all nodes to upgrade to the new version [1]. If some nodes do not upgrade, the blockchain can split permanently, sometimes creating a new cryptocurrency — history has several such examples.
What a soft fork is
A soft fork aims to stay backward-compatible: even if some nodes don't adopt the new version, they can still recognize and validate transactions made under the new rules [1]. A soft fork does not create a new coin; the original chain keeps running, just with added features.
At a glance
A hard fork and a soft fork differ on compatibility, on whether every node must upgrade, and on what the network is left with afterwards. A hard fork relaxes or removes rules, so every node has to move to the new version and the chain can split permanently, sometimes into a separate coin. A soft fork adds or tightens rules, so nodes that have not upgraded can still validate transactions under the new rules, and the original chain carries on.
The bottom line
Hard forks and soft forks are both ways a blockchain evolves: the former relaxes or removes rules and can split off a new chain; the latter adds or tightens rules while staying backward-compatible [2]. Understanding the difference helps you read major network upgrades. To keep learning the fundamentals, follow more from Bitbase Academy.
Related reading
Other Bitbase articles on this topic:
- Uncle Block vs Orphan Block: What's the Difference?
- What Is a Blockchain Fork?
- What Is Qubic? A Quorum-Based Computer for Smart Contracts
Disclaimer: This article is educational content from Bitbase Academy, provided for information only. It does not constitute investment, trading, tax, or financial advice. Written as of June 2026; refer to the latest official information.
References
[1] Coinbase, "What is the difference between a blockchain soft fork and a hard fork?" coinbase.com
[2] Fidelity, "What is a hard fork in crypto? Hard fork vs soft fork." fidelity.com
