What public test-networks exist and what are their conditions?
*All other Ethereum Layer 1 TestNets are deprecated, like Rinkeby and Ropsten.
**Solana does not have the concept of Chain IDs. Their most closely related concept would be a cluster.
B9lab have one deployed via IPFS. this is pretty neat. long description below, here is the one-liner for rushed users:
curl -X POST -H "Content-Type: application/json" -d '{"toWhom":"0xdcf407eae88d480e280db2d0deaa3a11c82eaa9b"}' https://ropsten.faucet.b9lab.com/tap
Replace 0xdcf407... with your testnet account. It will send 1 ETH by default. If you need more, you need to go to the IPFS interface:
$ geth --testnet --rpc --rpcport 8545 --rpcaddr 127.0.0.1 --rpccorsdomain "*" --rpcapi "eth,web3"
# in another terminal
$ ipfs daemon
And [visit localhost][2]. There is also an [IPFS gateway available][3] for the lazy.
Navigating to ropsten.ether.camp shows a huge button GET FREE ETHER at the top of the explorer. Click it, enter your address and recieve 5 test ETH.
[2]: http://localhost:8080/ipfs/QmVAwVKys271P5EQyEfVSxm7BJDKWt42A2gHvNmxLjZMps [3]: http://ipfs.b9lab.com:8080/ipfs/QmVAwVKys271P5EQyEfVSxm7BJDKWt42A2gHvNmxLjZMps
(Adding another answer rather than updating the community wiki answer, as it would involve changing most of what's there, and it may well be historically useful.)
What public test-networks exist and what are their conditions?
What are the connection data?
Geth: (Ropsten/Rinkeby)
Either specify the network using the ID (3 = Ropsten, 4 = Rinkeby) or using the --testnet or --rinkeby flags.
--networkid value Network identifier (integer, 1=Frontier, 2=Morden (disused), 3=Ropsten, 4=Rinkeby) (default: 1)
--testnet Ropsten network: pre-configured proof-of-work test network
--rinkeby
Parity: (Ropsten/Kovan)
Use the --chain flag.
--chain CHAIN Specify the blockchain type. CHAIN may be either a
JSON chain specification file or olympic, frontier,
homestead, mainnet, morden, ropsten, classic, expanse,
testnet, kovan or dev (default: homestead).
How often (if so) are they reset?
Does a public faucet exist for this test network?
Does a block explorer exist for this test network?
How frequent/ reliable are new blocks mined?
Any thing else user should know about this test network?
Don't assign value to test ether.
Just a heads up, we have created a universal Faucet here
The idea is to put as many networks together (and tokens) to make the experience smoother for developers.
UDPATED OCT 2022 - Goerli is now the only Ethereum testnet! Rinkeby, Ropsten, and Kovan are all deprecated because of the recent Ethereum merge.
If you need a reliable faucet, Alchemy has a good one - goerlifaucet.com. You just sign up for a free account, and you can get more free Goerli testETH every 24 hours.
March 2023 Update
GOERLI - There's a shortage in Goerli. If you need Goerli, you can use Alchemy's faucet: https://goerlifaucet.com.
SEPOLIA - Alchemy has launched support for Sepolia testnet and a free Sepolia faucet: https://sepoliafaucet.com.
From these faucet, you can get more testETH every day. Please only take what you need so there's enough for everyone.
A good list of public faucets can be found on https://faucetlink.to/
If you want to run a validator on Prater or Ropsten, you can join the EthStaker Discord server and access the #request-goerli-eth💸 or the #request-ropsten-eth💸 channel with a BrightID verified account to get enough testnet ETH to do your deposit.
Tested in Aug 2022:
As for May 2023 there are 2 public test-networks: Goerli (Chain ID: 5) and Sepolia (Chain ID: 11155111).
They both have testnet explorers:
Goerli: https://goerli.etherscan.io/
Sepolia: https://sepolia.etherscan.io/
To get free tokens you can use Alchemy's faucets: https://goerlifaucet.com and https://sepoliafaucet.com.
If you need more test tokens than these faucets provide you can buy some, as an altcoin GETH (Goerli ETH on mainnet) is available to buy on Uniswap and LayerZero made a bridge between mainnet and Goerli testnet. The site is https://testnetbridge.com. Swap and Bridge has a gas limit of 370,000 and depending on gas price the cost of transaction can be from few to even tens of dollars. To skip that high fee you can use a service from https://www.goerlieth.com/, where you can buy Goerli ETH starting from $1. They accept transfers on many networks, including Polygon that has really cheap fees.
Good luck with your projects!
Free Sepolia Testnet Faucet that lets you claim 0.5 Sepolia ETH per day.
You can use https://www.buildbear.io/ and create your own Testnet that comes with a built-in faucet.
I use GetBlock.io to connect to various test networks, including ETH Sepolia, BSC, Polygon Amoy, ARB Sepolia, Optimism Sepolia, and many others. They support a large number of Blockchain Testnets and some Faucets as well (I guess it's 50+ protocols supported in total) You can check it yourself here:
https://getblock.io/nodes/ https://getblock.io/faucet/
It's actually not completely public, as you used to think about it, cause you need to create an account first to get your private RPC endpoint, but they have a FREE plan that could be enough for many newbie developers like I was ;)
