<p>Testnet and mainnet are two different blockchains, and their coins are incompatible.</p>

<p>A transaction takes outputs that already exist on the blockchain, and re-assign them as outputs to different addresses.  Think of a blockchain as a database.  Let's say testnet has outputs A, B, and C.  They are in the <em>testnet</em> database.  However, <em>mainnet</em> has never heard of these outputs.  They simply don't exist in the mainnet database.  Any transaction that is submitted to mainnet using A, B, or C will be immediately rejected.  Likewise, if you submit the same transaction to testnet, then the transaction goes through...but it goes through on testnet.  Mainnet is still none the wiser.</p>

CC BY-SA 3.0
2018-03-22T20:29:17.100Z
2018-03-22T20:29:17.100Z
Jestin
<p>Why prevents bitcoins from being sent from the testnet to mainnet?</p>

CC BY-SA 3.0
2018-03-22T19:50:02.160Z
What prevents EUR from being sent to a USD bank account? They're different currencies; you need to exchange them as they have different market valuation.
Pieter Wuille
CC BY-SA 3.0
2018-03-22T19:59:18.223Z
But is it possible to exchange testnet coins for mainnet coins?
Errol
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2018-03-22T20:33:54.293Z
@Errol: Sure, if you could find somebody to exchange with.  Likewise, you could exchange Monopoly dollars for US dollars, if you could find someone willing to make the trade.  But nobody is going to want to do that, since testnet coins, like Monopoly dollars, aren't worth anything.
Nate Eldredge
CC BY-SA 3.0
2018-03-22T21:44:28.483Z
We actually do exchange dollars for Monopoly dollar ... plus plastic pieces and cardboard and other stuff at the toy stores.
Osias Jota
<transactions><testnet>
Why can't coins be sent from testnet to mainnet?
Errol
# Why can't coins be sent from testnet to mainnet?

(Asked by: username_0 on 2018-03-22)

Why prevents bitcoins from being sent from the testnet to mainnet?

**Tags:** transactions, testnet

> **Comments:**
> **username_1**: What prevents EUR from being sent to a USD bank account? They're different currencies; you need to exchange them as they have different market valuation.  
> **username_0**: But is it possible to exchange testnet coins for mainnet coins?  
> **username_2**: @username_0: Sure, if you could find somebody to exchange with.  Likewise, you could exchange Monopoly dollars for US dollars, if you could find someone willing to make the trade.  But nobody is going to want to do that, since testnet coins, like Monopoly dollars, aren't worth anything.  
> **username_3**: We actually do exchange dollars for Monopoly dollar ... plus plastic pieces and cardboard and other stuff at the toy stores.  

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## 1 answers

### Answer by username_4 on 2018-03-22. Score: 3 | Accepted answer

Testnet and mainnet are two different blockchains, and their coins are incompatible.

A transaction takes outputs that already exist on the blockchain, and re-assign them as outputs to different addresses. Think of a blockchain as a database. Let's say testnet has outputs A, B, and C. They are in the *testnet* database. However, *mainnet* has never heard of these outputs. They simply don't exist in the mainnet database. Any transaction that is submitted to mainnet using A, B, or C will be immediately rejected. Likewise, if you submit the same transaction to testnet, then the transaction goes through...but it goes through on testnet. Mainnet is still none the wiser.


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