Testnets exist on pretty much all networks in web3 — from Ethereum to BSC to Polygon to Palm. They're an essential element of a functioning smart contract ecosystem, since they allow developers of decentralized applications (dapps) to test their new creations before releasing them.
Testnets come with their own native tokens that mimic the native token of the corresponding mainnet. On Ethereum's testnets, known as Goerli and Sepolia, real-world ETH is simulated through testnet ETH, which you may see referred to as 'Goerli ETH' or 'Sepolia ETH'.
Crucially, testnet variants of ETH do not have any real-world value. This is what scams relating to testnet ETH hinge on; more specifically, they rely on users' ignorance of this fact.
Real ether is traded on the open market and has a fluctuating fiat price at any given time that reflects market conditions. Testnet ETH, on the other hand, is essentially worthless, since you can obtain virtually unlimited amounts for free from faucets (some are listed in this Ethereum Foundation article), if you have the patience.
How do these scams work?
In a nutshell, and as alluded to above, scams that involve testnet ETH rely on you not knowing — at the time of the scam being executed — that testnet ETH has no monetary value. This could be because you forgot, the UI on a dapp misled you, you believed the word of a bad actor, or you genuinely were not aware in the first place.
Whatever the reason, it's irrelevant to the scammer.
Here's how these tricks typically work:
The scammer sets up the scenario. If that sounds vague, it's because the scope of how this trap could be laid is pretty broad. Generally, they need to engineer a scenario where they can give you testnet ETH in exchange for an asset of actual value. Here are some examples:
- Scenario A: NFTs. Imagine you're an artist, and you have a few NFTs listed on a marketplace. You're just starting out, so you list items in a collection at 0.1 ETH each. One day, you wake up and see someone has offered you 5 ETH for one. Naturally, you rush to accept it.
- Scenario B: A real-world transaction. Sometimes bad actors may insist on paying you for a real-world item in crypto. Say, for example, you were happy to, as long as they sent a deposit first so you could check they were legit.
- Scenario C: You're trading in-game items. Tradable items in online games, especially ones already linked to the blockchain, lend themselves well to crypto payments: crypto transcends international banking systems and is quick and convenient. If both parties are willing, why not?
The scammer tries to convince you the ETH they sent has value. You'll probably be able to guess what happens next, regardless of which of the three scenarios we follow. The scammer has paid for their item or service in testnet ETH that has no real value — in other words, for free — and needs to convince you that everything is fine. Some tactics they may employ include:
- Demanding you connect to the testnet in your wallet. If you connect to a testnet in MetaMask, it's possible that you may see a fiat value (e.g. US dollars) that suggests the testnet ETH is worth something. This is turned off by default in MetaMask, but you may have it turned on, for one reason or another. The scammer will be banking on the fact that you will immediately relax once you see the fiat value/
- They give you instructions or guidance on trading the testnet ETH for tokens with real value. They may tell you have 48 hours, for example, to convert the tokens to real ETH, or you may be given a set of spurious instructions or a specific dapp that will let you convert the testnet ETH. Don't be fooled: there is no way of converting it into real value.
An example of a scammer attempting to convince a Reddit user to accept testnet ETH. From this thread.
- You send over the asset in question. The timing of this step and the previous is somewhat interchangeable: it's possible you might have already sent the NFT, for example, before the scammer's charm offensive begins. Either way, by the time you've parted with your cryptoasset, it's already too late. Blockchain transactions are immutable, so if you've already been convinced by the scammer that your testnet ETH has value and you've sent over the asset they requested, then it's extremely unlikely you'll be able to get it back.
How to stay safe
The main things to look out for to prevent yourself falling victim to a scam involving testnet ETH are:
- Urgency. Scammers often try to create a sense of urgency to make you think you'll miss out on free money if you don't act quickly.
- Unsolicited messages. To make this work, the scammer needs to reach out to you. This can be on any messaging platform (e.g. Telegram, Discord), social media platform (Reddit, Instagram, Twitter), or traditional communication method (SMS, email). Be sceptical of any such messages and assume they do not mean well.
- 'Too good to be true' offers/'free money'. If the supposed offer seems too good to be true, it probably is.
- Testnets are used primarily by developers to make sure their dapps work. The versions of ETH on testnets do not have any real value, as they can be obtained for free from faucets.
- Scammers exploit lack of awareness around testnets' purpose, making people believe that testnet ETH has value.
- The scam often involves fraudulent purchases of cryptoassets with testnet ETH, including NFTs, gaming collectibles, and more.
- Once users realize the ETH they received has no value, it's too late.
If you have any questions about this subject, feel free to head to the MetaMask Community or get in touch with Support via the 'Start a Conversation' button on the homepage of this site.