What is Blockchain Fork? How Does it Work?

You must have heard about fork that belongs to the cutlery. However, do you know that The Blockchains fork too? That is yet another aspect of Blockchain technology that helps you appreciate the democracy associated with it. In a typical software deployment, there is a central authority that is running the entire show. Therefore, they usually create the product, test it and then ship it to their customers. In case something goes wrong, they repeat the process and release an update right there and then.

But Blockchains? Well, they do not follow the web 2 rules of software lifecycle. Once a product (Blockchain) is developed, tested and shipped, it does not remain under the control of a single authority. Even the owners, who created that Blockchain, do not have solo rights to edit it. So one may ask at this point that how do Blockchains get upgraded? Well, that is primarily what we are going to talk about today. What is Blockchain Fork and how does it work?

What is Blockchain Fork:

The easiest way to visualize a Blockchain fork is to think of it as a chain of blocks stacked on the top of each other. As you all know, these blocks are meant to store data. Now, there are some rules governing the formation of these blocks. For example, there cannot be more than ‘X’ MB of data in each block. Another example could be that only ‘Y’ transactions could be added to a block.

Since every individual has their own copy of the Blockchain, one may decide to change these rules. But in that process, he/she would end up creating a different blockchain altogether. This new Blockchain would now be run on a different set of norms.

Therefore, what essentially happened here was that someone just ‘split’ the existing Blockchain into two different Blockchains. In other words, they ‘forked’ it.

A few imminent examples from the past for fork are Bitcoin Cash, Bitcoin SV, Bitcoin Gold, which are all the forks of Bitcoin.

Why Do Blockchains Fork?

There could be a couple of different reasons behind forking a Blockchain. Let us quickly go through each one of them:

Ideological Difference:

We discussed one of the example of forking where people with different ideologies may decide to quit the network and chose to run it in their own manner.

Philosophically, forking is the web3 manifestation of the concept of voice & exit.

Basically, at any point of time if sufficient network participants feel that the quality of the network is diminishing and they are unable to exercise change, not only can they leave – but they can take their data with them.

It feels like forking will replace “outrage” & “petitions” because it is simply a way more effective way.

One of the very famous forks in history due to the above mentioned reasons was for a famous decentralized exchange called ‘Uniswap‘. The decentralized exchange ‘Sushi Swap‘ was created after forking Uniswap.


This is where it gets really interesting. It is not possible for someone to simply upgrade the Blockchain at will. Not even for the founders. So usually, they release a proposal for upgradation. This proposal carries the details of upgrade, rationale behind it and the specific dates.

Post that, some Blockchains also seek votes from the people who are holding the native tokens. Basis their approval, the proposal goes ahead.

Once the proposal is passed, every node is requested to update as per the new protocol and rules.

All the nodes which fail to upgrade themselves are left behind basis the time of fork.

Yes you read that right. There are more than one type of forks. Let us discuss them in detail.

Types of Blockchain Fork:

Depending on weather or not the previous nodes are still able to operate in the system, forks can be divided into two parts. Hard fork and Soft Fork:

A. Soft Fork:

A soft fork is a type of fork which is backward compatible. This means that nodes with older software are allowed to create new blocks unless they break any protocol rules laid down by the update.

For example a protocol may decide to change the maximum storage size of the block from 3MB to 2MB. In this case older nodes can still create blocks with storage of 2MB or less. However, they would be rejected if they try to create a Block storage greater than 2MB. Why, because it violates the new rules of the Blockchain.

B. Hard Fork:

A hard fork is a permanent divergence made in a Blockchain that no longer accepts the blocks created by nodes that have not upgraded themselves. Adding a new rule in the Blockchain adds a fork in the Blockchain. This creates two new paths. One path that follows the the new rules, the upgraded blockchain and an older path, which is yet to upgrade.

As more and more nodes realize that their version of blocks is outdated, they would upgrade.

An analogy to understand hard fork would be a married couple. Imagine that your spouse tells you that if you don’t quit drinking, she is going to leave. You can continue drinking as usual, but she is not going to stick around. At the same time others who quit drinking under the same situation would upgrade in their lives.

A hard fork is incompatible with the previous version of the Blockchain. This means that nodes that do not upgrade would not be able to create blocks anymore. For example a protocol passes a rule that all the new blocks would have their storage increased from 2MB to 4MB. In this case, whenever the upgraded Blockchain will create a block with a size of 4MB, the older Blockchain would not be able to process it.

Hard Forks can be further sub-divided into two categories:

B.1 Planned Hard Forks:

In a planned hard fork, participants voluntarily upgrade to comply with the rules of the new Blockchain. Those who do not upgrade are left behind with the older Blockchain that very less people would be using.

B.2 Controversial Hard Fork:

In a controversial hard fork, two split Blockchains are split into two different incompatible Blockchains each having their own community and roadmap. Often the new Blockchain issues similar number of tokens which an individual had on the older Blockchain.

Examples of Blockchain Forks:

The world of Blockchains is full of different types of forks that we discussed above. However some of these forks have a really interesting history. We are sure that you would be awed after learning more about them:

A. Ethereum Classic:

This fork is a classic example of ideological forking. Back in 2016, there was a DAO or decentralized autonomous organization on Ethereum with funds worth $150,000,000 locked in it. However, one fine day, someone hacked the DAO and stole about $500,000 worth of Ethereum from that fund.

Since it was a hack, Vitalik Buterin, co-founder of Ethereum wanted to reverse this transaction and give them their funds back.

At this point some purists condemned this decision and believed that whatever has happened, has happened. Blockchains should not violate the ethos of immutability.

Hence, there was a hard fork. One Blockchain that emerged out of that fork is the Ethereum that we know of today, and the other one is known as Ethereum Classic. The original Ethereum without any changes.

B. EIP 1559:

Famously known as the ‘London Hard Fork‘, EIP 1559 fork happened in October last year. EIP stands for Ethereum Improvement Proposal. This was a planned hard fork that aimed to change the speed and incentivizing mechanism on Ethereum.

Unlike BTC, miners can charge ETH as per their convenience for validating transactions on Ethereum.

Once the update was rolled out, there was an upper limit that was put to the amount of ETH that can be charged. This constrained the supply of ETH in the network, this pushing up its value. Also, it gave the users predictability in terms of the gas fees that is being charged.

The upgrade ensured that no amount of network congestion results in shooting up Ethereum gas price.

C. Bitcoin Taproot Upgrade:

Another fork of recent times is Bitcoin Taproot upgrade that happened in November of 2021. Taproot upgrade simply batches the multiple transaction and signatures together. This helped in increasing the transaction speed of the overall network.

The Never Ending World of Blockchains and Crypto:

Are you overwhelmed by a new jargon popping up every time you try to decipher Blockchain and crypto world? We’d rather say, that is the beauty of it. There is just so much to learn.

Got questions? Want to take it to the next level? Reach out to me using your preferred platform from the links below

Until next time..

For our beloved “non readers”, I also do quick carousels on these topics over Instagram. Come join the fun. Hit me up here.

Btw, if you are a seasoned trader or just testing the waters with derivatives, here’s an exchange specifically meant for that. Head over to MCS using this link. Still not convinced? Join the vibrant community that is talking about MCS on Telegram, here.

A techno manager by profession and a hardcore geek at heart. I love to poke my nose into tasks where other usually gave up on. My hobbies include, reading about Blockchain, Cryptocurrency and latest trends in tech industry, playing guitar and yes, memes!

2 thoughts on “What is Blockchain Fork? How Does it Work?

Leave a Reply