Every Solana transaction pays two layers of fee, and a third optional payment lives entirely off-chain. Conflating them is the single most common reason a well-funded trade stalls in a leader's queue while a rival mint or liquidation lands first.
This guide takes the stack apart. Base fees are a flat lamport tax. Priority fees are a compute-unit auction. Jito tips are an off-chain side market that ~92% of Solana validators now tap into. You need all three to reason about what "gas" means on this chain — and why it does not resemble Ethereum's EIP-1559 and priority-fee model at all.
The flat base fee: a fixed constant, not a market
Every Solana transaction pays a base fee of 5,000 lamports per signature. A lamport is 10⁻⁹ SOL, so a single-signature transfer costs exactly 0.000005 SOL in base fee — regardless of the mempool, the validator queue, or how congested the network happens to be that second. A multisig transaction with three signers pays 15,000 lamports. A transaction with no signers does not exist.
Half of each base fee is burned. The other half goes to the current leader, the validator elected to produce that slot (see Part 2 on PoH and Tower BFT for how that election works).
This is where readers coming from Ethereum tend to trip. On Ethereum, the base fee floats according to an EIP-1559 formula and is 100% burned — it is the mechanism that prices congestion. On Solana, the base fee is a hard-coded constant. It does not rise when blocks are full. It exists mainly as a Sybil cost on signature verification, not as a congestion signal. If you rely on the base fee alone during a busy block, your transaction will sit in the scheduler while higher bidders skip the line. The Bitcoin block-space fee market is also a true market; Solana's base fee is neither.
All the scarcity pricing on Solana happens in the next layer.
Compute units and the priority-fee auction
Solana meters execution in compute units (CU) rather than gas. The protocol caps a single transaction at 1,400,000 CU, and each instruction defaults to a 200,000 CU budget. Spend more, and your transaction fails with an out-of-budget error.
To influence whether your transaction is selected when blocks are contested, you attach two instructions from the ComputeBudget program:
SetComputeUnitLimitraises or lowers the CU ceiling for your transaction.SetComputeUnitPricesets a priority-fee bid in micro-lamports per CU, where 1,000,000 micro-lamports equals one lamport.
The total priority fee you pay is ceil(price × limit / 1,000,000) lamports. A swap that needs 200,000 CU at a 10,000-micro-lamport price pays 2,000 lamports of priority fee. At 100,000 micro-lamports per CU, that same swap pays 20,000 lamports — still a fraction of a cent in USD terms, but enough to re-order you inside the leader's bundle.
Two details matter here.
SIMD-0096 changed the burn policy. Solana validators voted in May 2024 to approve SIMD-0096, and the change activated on mainnet on 12 February 2025. Before activation, priority fees followed the base-fee split: 50% burned, 50% to the validator. Since activation, 100% of the priority fee goes to the current leader and 0% is burned. That is a meaningful monetary-policy shift: it increased the share of total economic activity that flows to validators (and, as we'll see, to liquid-staking holders) versus being destroyed.
Solana has local fee markets. The scheduler prioritises transactions on a per-hot-account basis. A transaction touching a viral memecoin pool or a hot NFT mint is contested; one transaction touching only your own keys is usually not. Global median priority-fee readings on explorers are close to useless here — they understate what you need for a hot account and overstate it for vanilla transfers.
Jito-Solana: the validator fork that runs the network
Sitting above the protocol's fee market is an entirely separate MEV auction run off-chain.
Jito-Solana is the Jito Foundation's open-source fork of the Agave validator client. It is a drop-in replacement for the reference client that additionally connects each validator to Jito's off-chain Block Engine. By the start of 2025, about 92% of Solana's staked SOL is delegated to validators running Jito-Solana — up from 48% a year earlier. For practical purposes, the MEV layer is network-wide infrastructure, not a minority experiment.
The Block Engine runs a continuous, high-frequency auction during each leader's slot. Searchers — independent MEV bots — submit bundles: ordered sequences of transactions that must execute atomically, all or nothing. Each bundle attaches a tip to one of eight designated tip accounts, with a minimum of 10,000 lamports per bundle.
The engine simulates submitted bundles, picks the combination that maximises total tips without conflict, and forwards that merge-ready stream to the leader. The leader stitches the winning bundles into the block along with the regular priority-fee queue.
One critical caveat: Jito's public mempool was suspended in March 2024 to reduce sandwich-attack MEV on retail swappers. Solana has no native in-protocol mempool, so sandwiching largely moved to opaque private mempools run by third parties. It is diminished, not eliminated. Active MEV on Solana today is dominated by arbitrage (CEX/DEX, DEX/DEX, cross-chain), onchain liquidations, and NFT mint sniping.
Priority fees vs Jito tips: do not confuse them
This is the paragraph worth re-reading.
A priority fee is a protocol-level payment set via the ComputeBudget program. It is denominated in micro-lamports per CU, paid in-transaction, and distributed 100% to the leader via the standard runtime.
A Jito tip is an off-chain payment inside a bundle, denominated in whole lamports, sent to a specific tip account, and distributed through Jito's infrastructure — not the protocol. Jito Labs takes a 5% commission on tips; the remaining 95% lands in the validator's tip account.
They are set differently, paid differently, and routed differently. A transaction can use one, the other, both, or neither. Retail wallets almost always use only priority fees; professional searchers typically use bundles with tips, and often priority fees too for execution guarantees inside the bundle.
How MEV flows back to stakers via JitoSOL
The 95% of each tip that reaches a validator's tip account does not stay there. Most Jito-Solana validators are delegated through the Jito Stake Pool, which pools stake and issues JitoSOL, a liquid-staking token. MEV tips earned by pool validators are socialised across JitoSOL holders pro rata, on top of ordinary staking rewards.
In typical conditions JitoSOL yields roughly 1–2% more APY than plain native staking, varying with MEV intensity. Retail holders who never run hardware or search bundles still capture MEV economics by holding a liquid-staking derivative.
Ethereum parallel, in one table
| Layer | Ethereum | Solana |
|---|---|---|
| Base fee | Floats, 100% burned | Flat 5,000 lamports/sig, 50% burned |
| Priority fee | To proposer (tip) | To leader, 100% since SIMD-0096 |
| MEV layer | MEV-Boost relays + PBS builders | Jito Block Engine bundle auction |
| MEV market share | Distributed across relays | ~92% via Jito-Solana |
| Retail MEV capture | stETH, rETH, etc. | JitoSOL |
Ethereum burns more, distributes MEV through a multi-relay market, and keeps proposer payouts smaller. Solana burns less, concentrates MEV through one dominant Block Engine, and routes more of the economics to validators and their stakers. Neither model is "better" in the abstract — they reflect different priors about neutrality versus validator revenue.
Practical guidance for wallet users
A few rules of thumb for setting fees from a Solana wallet, which builds on the generalist beginner primer on transaction fees and the wallet-side fee UI when sending crypto:
- Casual transfers during low congestion: skip the priority fee. The 5,000-lamport base fee is sufficient.
- DEX swaps and DeFi during contention: set a priority fee. A reasonable starting CU price for congested Jupiter or Raydium routes is 1,000–50,000 micro-lamports per CU. During memecoin launches or liquidation cascades this can spike sharply.
- NFT mints on a hot program: go higher. Fee-estimator RPCs like Helius's or Triton's can read local-fee-market percentiles rather than global medians.
- Do not confuse priority fees with Jito tips in your wallet UI. Most wallets expose only the priority-fee field. Some advanced RPC endpoints auto-route tagged transactions through the Block Engine, but that is a backend choice, not something a typical user configures.
When a transaction silently stalls, the cause is almost always an undersized priority fee on a hot account — not the base fee, not a validator outage.
Key takeaways
- Solana's base fee is a flat 5,000 lamports per signature, half burned and half to the leader. It does not price congestion.
- Priority fees are the real congestion market: micro-lamports per CU, set via the ComputeBudget program, and 100% to the leader since SIMD-0096 activated on 12 February 2025.
- Priority fees and Jito tips are different payments with different routing. Jito tips are off-chain bundle bids, ~95% to the validator after Jito's 5% commission.
- Jito-Solana runs ~92% of Solana stake; JitoSOL holders capture MEV indirectly through the Jito Stake Pool.
Part 4 steps inside the validator itself: staking economics, delegation, and how the forthcoming Firedancer client reshapes consensus performance.
