Level 3 · Module 3.4
Networks, Fees, and SOL
Three practical concepts that trip up almost every new Solana user: the difference between the networks, why you always need SOL even to send other tokens, and how to spot a suspicious fee before it costs you.
⏱ 7 min read
🟡 Practical
📖 4 sections
01 Three Networks, Three Realities
Solana doesn't have just one network — it has three, and confusing them is an expensive mistake. The UI in Phantom looks identical across all three. Only the network indicator tells you which you're on.
MAINNET
The real network. Real SOL. Real tokens. Real money. Transactions are irreversible. Every mistake here has actual financial consequences. This is where you live once you're ready.
TESTNET
A copy of Mainnet used by developers to test smart contracts before deploying them with real money. Tokens have no value. Mostly used by developers, not end users.
DEVNET
The practice network. SOL is free via airdrop and has zero real value. This is where Solana Wizard's Workshop runs. Everything you do in Level 4 happens here — safely, with no financial risk whatsoever.
⚠️
The Most Common Beginner Mistake
Forgetting to switch back to Mainnet after practicing on Devnet — and then accidentally sending real funds to a Devnet address. Or the reverse: thinking you're on Devnet and accidentally spending real SOL. Always confirm your network before any transaction.
02 Why Fees Exist
Every blockchain charges fees for a reason — three reasons, actually:
VALIDATOR COMPENSATION
The computers that process and verify your transactions are owned by people who pay for hardware, electricity, and bandwidth. Fees are their compensation for maintaining the network.
ANTI-SPAM
Without fees, someone could send billions of meaningless transactions per second and paralyse the network. Fees make this economically irrational — even at $0.00025.
PRIORITY
During high congestion, adding a priority fee moves your transaction to the front of the queue. On Solana this is rarely necessary, but it's an option.
03 SOL: The Fuel for Everything
This confuses nearly every new Solana user: you need SOL to do anything on Solana — even when transacting with other tokens.
Want to send USDC to someone? You need SOL for the fee. Want to swap tokens on Jupiter? SOL for the fee. Want to receive a token for the first time? SOL for the account deposit. There is no action on Solana that doesn't require SOL as the underlying fuel.
MINIMUM BALANCE
Always maintain at least 0.05–0.1 SOL in your wallet. This covers hundreds of transactions before you need to top up. Running to zero SOL locks your wallet — you can't even send SOL to refill it without SOL to pay the fee.
RENT DEPOSIT
Opening a new token account (the first time you receive any specific token) costs ~0.002 SOL as a rent deposit. This is refundable if you close the account later — but you need to have it upfront.
NEVER SEND ALL SOL
If you transfer 100% of your SOL, you'll have nothing left for fees. Your wallet appears empty but is actually just out of fuel — not technically frozen, but practically unusable until you receive more SOL.
04 Solana Fees vs Ethereum Fees
One difference that matters practically:
| Situation | Solana | Ethereum |
|---|
| Normal fee | ~$0.00025 | $0.50–$100+ |
| Transaction fails | No fee charged | Gas used before failure is lost |
| Fee > $0.01 for simple tx | Red flag — possible malware | May be normal congestion |
| Out of fee token | Transaction rejected | Transaction rejected (and you lost the gas) |
On Solana: if a simple token transfer shows a fee above 0.01 SOL (~$1.50+), stop. Normal operations cost fractions of a cent. An abnormally high fee is the fingerprint of a malicious contract — not congestion.
You are now ready for Level 4. You understand the theory, you have a wallet, you know the threats. In the Workshop, you'll perform every real operation — airdrop, transfer, create a token, explore the blockchain — using free Devnet SOL with zero financial risk. Theory becomes practice.