Bitcoin forks explained: every major fork and what happened to it

Bitcoin has no company behind it, no CEO and no update button. Nobody can push a new version to the network the way Apple pushes software to your phone. Changes happen through open proposals, years of public argument and, occasionally, an outright split in the network itself. Those splits, and the upgrades that avoid them, are what we mean by Bitcoin forks. Their history is really a history of who controls Bitcoin: not the miners or the developers, but the people who run the software and hold the coins.

This guide covers every fork that mattered: what each tried to change, who pushed it, and what the market decided each new coin was worth.

What is a Bitcoin fork?

A Bitcoin fork happens when the network's rules change. If the new rules stay compatible with the old ones, it is a soft fork and the network stays whole. If they are incompatible, it is a hard fork: the blockchain splits into two chains, and holders end up with coins on both.

The word covers two ideas that often get blurred. Developers sometimes copy Bitcoin's open-source code and launch a brand-new network: Litecoin did this in 2011, and hundreds of altcoins followed. Those code forks hand nothing to bitcoin holders. A chain split is different. The new chain shares Bitcoin's entire history up to the split, so every balance that existed before it exists on both chains afterwards. (If blocks, nodes and miners are still fuzzy, start with how Bitcoin works and come back.)

Here is the part that matters: anyone can hard fork Bitcoin at any time. I could release a version of the software tomorrow that awards me Satoshi Nakamoto's estimated million-coin stash and declare mine the true Bitcoin. Nobody would follow, so my million coins would be worth what a £1 million note drawn in felt tip is worth. A fork only counts if users, miners, exchanges and developers choose to adopt it. Bitcoin is a protocol wrapped around a human agreement, and the agreement carries the value; that is also why coins on Bitcoin's testnet, a rehearsal network running near-identical code, trade for nothing.

What is the difference between a soft fork and a hard fork?

A soft fork tightens the rules in a backwards-compatible way, so nodes that never upgrade still accept the new blocks. A hard fork loosens or rewrites rules in a way old software rejects, which splits the chain. SegWit and Taproot were soft forks; Bitcoin Cash and Bitcoin Gold were hard forks.

Why the preference for cautious soft forks? Because mistakes here are uniquely unforgiving. If a social network ships an update that leaks your posts, it apologises and rolls it back. Bitcoin transactions are final: an upgrade bug that let a thief spend other people's coins could never be undone, and could sink the whole project. So Bitcoin steers like a loaded cargo ship, not a speedboat, and every change starts life as a public Bitcoin Improvement Proposal in the BIPs repository.

Bitcoin has also forked by accident. In August 2010 someone exploited an overflow bug to conjure 184 billion BTC in a single transaction; within hours Satoshi shipped a patch and the poisoned chain was abandoned. In March 2013 a database quirk briefly split upgraded nodes from older ones, and the big mining pools downgraded to reunite the network. Both incidents ended the way every fork fight since has ended: with rough human consensus about which chain is Bitcoin.

The major Bitcoin forks at a glance

Nearly two decades of arguments, compressed into one table.

What were the block size wars?

The block size wars were a fight, roughly 2015 to 2017, over how much data a Bitcoin block should hold. One camp wanted bigger blocks for cheaper payments; the other argued big blocks would centralise the network. It ended with SegWit activating and the big-block camp splitting off as Bitcoin Cash.

Bitcoin blocks were capped at 1MB, one roughly every ten minutes: only a handful of transactions per second. As adoption grew, blocks filled and fees climbed. The obvious fix, raising the cap, had a hidden cost: bigger blocks swell the blockchain faster, pricing ordinary people out of running nodes and hollowing out the decentralised check on miners. Proposals ranged from 2MB to 20MB, and rival clients (Bitcoin XT, Classic, Unlimited) each tried and failed to rally the network behind them.

The compromise was Segregated Witness, or SegWit, specified in BIP141. Rather than raise the 1MB base block, it moved signature data (the "witness") into an extended section that older software never sees, under a new 4-million-unit "block weight" limit allowing roughly 4MB of total data. Old nodes keep validating the familiar base block; upgraded nodes enforce the signatures. SegWit also fixed transaction malleability, an old flaw in how transaction IDs worked, which later made the Lightning Network practical.

Users and businesses broadly wanted SegWit. Miners stalled, and it later emerged the upgrade was incompatible with a covert efficiency trick called ASICBoost that gave some large operations a quiet edge and a private reason to resist. The answer was BIP148, the user-activated soft fork (UASF): from 1 August 2017, nodes running it would reject blocks from miners not signalling for SegWit. The threat has teeth, because a miner whose block the nodes reject has burned an enormous electricity bill for nothing. A compromise, SegWit2x, would have added a 2MB hard fork, but was called off for lack of support. Facing the deadline, miners locked SegWit in; it activated on 24 August 2017 at block 481,824.

The episode settled a constitutional question. Earlier upgrades had given miners an effective veto through a 95% signalling threshold; the UASF showed miners are paid to follow Bitcoin's rules, not to write them, and that the humble node, cheap to run on a second-hand laptop, is where enforcement really lives.

What happened to Bitcoin Cash and Bitcoin SV?

Bitcoin Cash split from Bitcoin on 1 August 2017 with 8MB blocks and cheap-payments ambitions. Bitcoin SV then split from Bitcoin Cash in November 2018 after an internal power struggle. Both chains still run, and both have lost more than 98% of their value against bitcoin since their peaks.

Bitcoin Cash was the big-block camp's answer to losing the SegWit argument: leave, and take a copy of the ledger along. The new chain launched with an 8MB limit, later raised to 32MB, championed most loudly by the early Bitcoin evangelist Roger Ver. Because it was a genuine chain split, anyone holding bitcoin at the fork automatically held the same number of BCH, spendable with the same private keys. (Controlling your keys matters; our guide to Bitcoin wallets explains why.) Reuniting the chains is now impossible: each holds years of transactions the other has never seen.

Then the new chain re-ran the same drama internally, a proper People's Front of Judea moment. In November 2018 a faction fell out with the rest of the Bitcoin Cash camp and forked again, creating Bitcoin SV ("Satoshi Vision"), fronted by Craig Wright with backing from Calvin Ayre. BSV pushed block sizes into the hundreds of megabytes and later removed the cap entirely. Wright spent years insisting he was Satoshi Nakamoto; in March 2024 the UK High Court ruled the evidence against his claim overwhelming. His fondness for suing critics had already helped get BSV delisted from major exchanges, including Binance, in 2019.

Both networks still produce blocks. Neither is Bitcoin: not by hashrate, node count or market value, and not in the judgement of the overwhelming majority, who never stopped reserving the name for the original chain.

What about Bitcoin Gold and the minor forks?

Bitcoin Gold forked in October 2017 to make mining possible on ordinary graphics cards rather than specialist hardware. It suffered 51% attacks in 2018 and 2020 and lost over 99% of its value against bitcoin. Dozens of smaller forks, Bitcoin Diamond and Bitcoin Private among them, fared no better.

Bitcoin Gold split off at block 491,407 with a different complaint: not block size but mining centralisation. Swapping Bitcoin's SHA-256 algorithm for Equihash was meant to shut out industrial ASIC hardware and give mining back to hobbyists with graphics cards. The flaw was as obvious as the appeal. A small chain with modest, rentable hash power is cheap to attack, and in May 2018 attackers rewrote recent history to double-spend roughly $18 million through exchanges, with another attack in January 2020. Delistings and punishing confirmation requirements followed.

The visibility of Bitcoin Cash and Bitcoin Gold set off a fork rush through the winter of 2017 and 2018: Bitcoin Diamond, Super Bitcoin, Bitcoin Private and, genuinely, Bitcoin God. The recipe never varied: fork the chain, hand every holder free coins, ride the headlines. Neither did the result, because a fork can copy the ledger but not the things that make it worth copying: the developers, the security budget, the liquidity, the credibility. Nearly all of these coins now trade at or near zero against bitcoin.

How do Bitcoin upgrades happen now?

Slowly and deliberately. Changes start as Bitcoin Improvement Proposals, get argued over for years, run on test networks, and only activate once an overwhelming majority of the network signals support. Taproot, activated in November 2021, is still the most recent consensus change, and nothing since has come close to activation.

The pipeline runs like this: an idea is written up as a numbered BIP and pulled apart in public. If it survives, it is implemented and rehearsed on Bitcoin's test networks, where coins are deliberately worthless so failure costs nothing. Only then does an activation mechanism invite the network to opt in, usually via miners signalling readiness in their blocks. It is the discipline the white paper implied: no administrator, only rules participants choose to enforce.

Taproot is the modern showcase. A bundle of three proposals, including BIP341, it locked in through a miner-signalling scheme called Speedy Trial and went live on 14 November 2021 at block 709,632, with none of SegWit's brinkmanship. It replaced Bitcoin's ECDSA signatures with Schnorr signatures, which can be aggregated: a multisig spend now settles as one compact signature, cheaper and indistinguishable from an ordinary payment. Its Tapscript component lets a coin carry several alternative spending conditions while revealing only the one actually used.

Taproot also produced a great unintended consequence. From January 2023, developers worked out how to use its flexible witness space to inscribe arbitrary data onto individual satoshis: images, text, even a playable copy of Doom. Ordinals and BRC-20 tokens drove such demand for block space that in May 2023 some blocks paid miners more in fees than in newly minted coins, while critics denounced it all as graffiti. Either way, it proved a backwards-compatible upgrade can still reshape Bitcoin in ways its designers never imagined.

Since Taproot, nothing has activated. Covenant proposals such as BIP119's OP_CTV and a revived OP_CAT have been debated for years without nearing consensus as of mid-2026. For a network securing other people's savings, slow is the point. How the surrounding pieces fit together is covered across the rest of this guide.

What happened to the value of the fork coins?

Every major fork coin has lost the bulk of its value against bitcoin. Bitcoin Cash is down more than 98% from its late-2017 peak in bitcoin terms, Bitcoin SV more than 98% since launch, and Bitcoin Gold over 99%. The market has consistently treated the original chain as the real Bitcoin.

The pattern is strikingly uniform. Bitcoin Cash peaked against bitcoin during the December 2017 mania at roughly a quarter of a bitcoin per coin and has bled ratio ever since. Bitcoin SV never approached its parent's peak and drifted further after the delistings. Bitcoin Gold's chart against bitcoin is a staircase down, punctuated by 51% attacks. The minor forks round to zero. None of this is a forecast; it is simply the recorded history. Every attempt so far to out-Bitcoin Bitcoin by forking it has been repriced by the market to a small fraction of the original.

The reason runs through this whole story. A fork duplicates the database, but value never lived in the database. It lives in the human consensus around one particular chain, and that consensus has proved far harder to copy than the code.

Frequently asked questions

Do I get free coins when Bitcoin forks?

If you hold bitcoin in a wallet where you control the private keys at the moment of a hard fork, the same keys control equal balances on the new chain. Exchanges decide for themselves whether to credit customers. In practice, most fork coins have proven to be worth very little.

Is Bitcoin Cash the same as Bitcoin?

No. Bitcoin Cash split from Bitcoin in August 2017 and has been a separate network, with its own coin and its own price, ever since. Millions of transactions now exist on each chain that do not exist on the other, so the two can never be merged back together.

Was SegWit a hard fork?

No, SegWit was a soft fork. It kept the 1MB base block valid for old software while letting upgraded nodes read up to 4MB of total block weight. Nodes that never updated carried on working, which is exactly what makes a soft fork backwards compatible.

How many times has Bitcoin forked?

Counting is fuzzy because anyone can fork Bitcoin at any time. There have been well over a hundred named fork coins, most launched during the 2017 to 2018 fork rush, but only a handful (Bitcoin Cash, Bitcoin Gold, Bitcoin SV) ever sustained meaningful markets, and all have faded against bitcoin.

Will Bitcoin fork again?

Almost certainly, in the technical sense: anyone can copy the code and split off whenever they like. Whether any future fork matters is a different question. History shows a fork only carries value if a large share of users, miners, exchanges and developers choose to follow it.