Bitcoin Forum

I've always been curious - who creates testnet coins? If they have no value, I'm sure there would be no incentive to mine them - so where exactly do they come from? Who holds them, and why? What is the testnet supply cap? I'm sure that if thousands of shitcoins have value, then a BTC testnet coin would also eventually have value, so why doesn't the testnet coin immediately gain some form of value (since it is scarce and acts exactly like BTC)?

BTC testnet coins are for the purpose of....testing. It is because it's dangerous to push untested code to the live network. One small bug could produce dao-like disaster, wrecking the billion-dollar ecosystem. Testnet allow developers to experiment in safety. Every bitcoin client or wallet can be used for testnet.

There have been 3 versions of testnet. The current Testnet3 was introduced with the 0.7 release. Start your typical bitcoin or bitcoind (daemon) with the -testnet flag to use the testnet or you can put testnet=1 in the bitcoin.conf file.

Yes, I am well aware of all of that. You still didn't answer a single one of my questions, though

https://testnet.blockexplorer.com/

That still doesn't answer my question... my question mainly is, why does a scarce currency like the BTC testnet coin not have value at all? And who creates them, distributes them, mines them (since they have no value), etc etc. Please don't post here if you can't answer my questions.

I think what is trying to be expressed here is that testnets are highly susceptible to the developers changing the code due to errors that were not foreseen. In programming this happens alot. So holding a testnet coin or mining on a testnet for the purpose of profit doesnt make much sense.

people who run testnets do so to test their code without incurring the risk of valuable mainnet loosing coins or competing in the mainnet which requires alot of computational power. A software engineer would run a testnet with some isolated ASICS, therefore the mining difficulty would be very low and they can mine the coins of that testnet easily to test features of their code. If their code is a mess they can discard these mined tokens which are worthless anyway :)

Wouldn't this mean that testnet coins have a very very low, albeit non-zero value?

Let me dumb it down.

who creates testnet coins?
You. Your wallet can mine it. Anyone who cares to keep the test environment alive.

If they have no value, I'm sure there would be no incentive to mine them
The incentive is the safe testing environment.

- so where exactly do they come from? Who holds them, and why?
From mining. Anyone can hold. You can get 50+btc testnet coins if you like.

What is the testnet supply cap?
Same as BTC

why doesn't the testnet coin immediately gain some form of value (since it is scarce and acts exactly like BTC)?
Because it's only for testing. No one will accept something that can be reset, recoded or rewritten at any moment.

"value" is a term that is used to describe the utility of a resource. In a testnet, the coins mined are a resource. the utility of this resource comes from the ability for the developer to test their code. so they have value to the people running tests. But this utility is not tangible to an open market like a mainnet coin.

Thanks for the answers! That was helpful. I'd imagine that testnet coins would still have a value of a few cents, right?

I don't know. You can collect 5 - 50 testnet BTC coins from faucets. So I don't think you can sell something that is freely given.

Odd because I've occasionally seen people buying 1000 testnet coins for 0.001 BTC, and similar deals. Anyway, thank you for your help, I think I get it now.

When i run a bitcoin core node in testnet, how do i mine bitcoin in testnet? What is the settings in bitcoin.conf ? 

The setgenerate is not working, see below:
./bitcoin-cli -testnet setgenerate true

No, because testnet coins are freely given away and in large quantities. They are not traded anywhere. Some scammers may claim that testnet coins have value and try to sell testnet coins, but they are easily obtainable for free.

If testnet coins were to have a value, then the testnet would be reset and started from scratch. This has happened twice already; the original testnet was discarded and replaced with testnet2. When testnet2 was being traded for money, it was discarded and replaced with testnet3. Testnet3 is the current iteration of testnet, and it can be discarded and replaced with a new testnet.

Miners do. People mine on testnet.

The incentive is a safe testing environment where people can do crazy things without risking any money. Some of those things may involve mining, so people will mine on testnet. Others may decide to mine testnet coins to use for themselves, so they mine on testnet. And others may use testnet frequency and just need it to not be dead so they can test things on it, so they mine it. The difficulty of testnet is so low that it can usually be CPU mined. At other times, it can be gamed into CPU mining difficulty levels since testnet has a difficulty reset mechanism.

Developers and people who want to test things without risking money.

Sam as Bitcoin's, ~21 million

Because if it were to have value, then testnet loses its value as a testing ground (place to test with coins that can be gotten for free). Additionally, the testnet can be reset and has been reset in the past.

How do you know that it isn't working? setgenerate doesn't give any visible output. And testnet still has a difficulty, so it takes time to mine blocks.

Thank you, that really clears things up. Especially the part about testnets being discarded in the past.

Well, they're utilized solely for testing. They help give development options and allow for prototyping :)

(I began slowly writing this earlier.  Part is made redundant by achow101’s excellent response; part is not.)


In addition to what others have said:  Believe it or not, some people do things for ideological reasons.  There are Core developers and others who have devoted huge chunks of their lives to Bitcoin, and have much less to show for it in material terms than they properly deserve.  There are people on this forum who make excellent quality posts, and receive in return via sig ads only a minute fraction of what they’d make if they were to spend the same time on commercial ventures—or receive nothing at all; some of the best posters don’t have sig ads.  (Here in this thread:  What do you think achow101’s time as spent here would be worth on the commercial market?)  And for my part, though I haven’t (yet) done much of anything for Bitcoin, I myself am much less rich than you’d guess due to my innate propensity to act for principles instead of money.

Bitcoin would not exist without people who believe in Bitcoin.  Its ancestry rose from the cypherpunk dreams of people who are ideologically driven.  It was conceived and borne forth into this world by an anonymous individual who acted only for principles, and to this day has (for whatever reason) not touched coins now worth billions of dollars.  It has been carried forward, improved, and maintained to this day by people who are primarily driven by ideology.  Some of them also make good money—some don’t, but do it anyway.

If you want to see what a “coin” looks like when its development and maintenance is driven solely by material “incentives”, look to Btrash.  That’s a good example—except that it’s a cheap knockoff which would never have existed at all, if it hadn’t been able to fork off the labours of love by people who believe in Bitcoin.


This popular testnet faucet (https://testnet.manu.backend.hamburg/faucet) (one of many) has a current available supply of 29436.93 testnet coins.  You get coins from the faucet, you use them to test software, and then you send leftover coins back to the faucet’s return address.

Testnet coins can be destroyed at any time.  They can be destroyed by accident, via a software bug—or the whole testnet can be destroyed intentionally.  This was the reason why we’re on Testnet3, as cannycassiopeia said.  Testnet2 was intentionally destroyed because some idiots were using testnet coins as money.

Testnet coins are mined by volunteers.  It has lower difficulty than mainnet, and a little quirk which drops the difficulty to minimum for the next block if no block is found for too long.


No, it does not act “exactly like BTC”.  The whole network can be destoyed at any time, by accident or intention.  Also, it is unlike BTC insofar as people who use BTC as money are smart, and people who use testnet coins as money are imbecilic scammers.


No.  The monetary value of testnet coins is zero.


Well, people can.  Developers can also respond to such a moronic thing by trashing the entire testnet anytime.  Then, we’d have Testnet4.


That is a scam.  Call it out as such.

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Bitcoin Core also has a regtest (regression test) mode, in which blocks can be mined instantly.  This is not a network; it is for testing and debugging code on your local machine, with a local instant-mine blockchain.  Install Core, and have fun with godlike powers creating as many disposable blockchains as you want!  Just don’t try selling any coins from them.  That would also be a scam.