Aztec Network vs Railgun: Which Privacy Protocol Has the Lower Fees?
In the privacy protocol space on Ethereum and compatible chains, Railgun and Aztec Network represent two leading but architecturally different approaches to shielded (private) transactions and DeFi interactions.
- Railgun — an overlay privacy layer (smart contract system) on Ethereum L1 and several L2s (Polygon, Arbitrum, BNB Chain). It uses zk-SNARKs to create shielded pools (0zk addresses) for private balances, transfers, and DeFi interactions via adapters.
- Aztec Network — a dedicated privacy-focused zk-Rollup (Layer 2) on Ethereum. It enables programmable private smart contracts, encrypted execution, and batched private transactions with data posted to Ethereum L1.
The key question: which one actually costs less in fees for typical privacy-preserving actions (shield/deposit, private transfer/swap, unshield/withdraw)?
Fee Structures (as of February 2026)
Railgun fees (from official docs, Messari valuation report, and protocol treasury mechanics):
- Shielding (deposit to private balance): 0.25% of the amount
- Unshielding (withdraw to public): 0.25% of the amount
- Private-to-private transfers/swaps inside the shielded pool: 0% protocol fee (only gas + optional broadcaster/relayer fee)
- Broadcaster/relayer fee: variable, often ~10% premium on gas price (paid to third-party relayers for private tx submission)
- Gas: full Ethereum L1 gas (or L2 gas on supported chains) — expensive on mainnet (~$5–$50+ depending on congestion), cheaper on Arbitrum/Polygon
Total effective cost for a round-trip (shield → private swap → unshield): ≈ 0.50% protocol fees + gas + broadcaster premium Private-only actions (once shielded) are very cheap — just gas/broadcaster.
Aztec Network fees (from docs, older zk.money era data, and post-Ignition Chain updates):
- No fixed percentage fee like 0.25% — fees are mana-based (Aztec's internal unit for computation) and paid in $AZTEC token (bridged from L1).
- Gas/mana costs are dramatically lower due to batching/rollup compression — often 80–99% cheaper than Ethereum L1 equivalents.
- Historical zk.money (Aztec v1/v2) examples: privacy overhead ~1,875–6,896 gas per tx (sub-cent to a few dollars even at high gas prices), with complex DeFi txs up to 100x cheaper than L1.
- Current Ignition Chain (2025–2026 mainnet): batched private txs → very low per-user cost (often cents), but includes L1 data posting + proof verification overhead.
- No explicit % fee on shield/unshield — cost dominated by L1 calldata + proof verification amortized over the batch.
Total effective cost for a round-trip (shield → private action → unshield): Usually much lower absolute dollars than Railgun (thanks to batching and L2 scaling), especially for high-frequency or complex operations.
Side-by-Side Comparison (Typical Use Cases, Feb 2026)
| Action / Scenario | Railgun Fee | Aztec Fee (approx.) | Winner (Lower Cost) |
|---|---|---|---|
| Shield / Deposit $1,000 | $2.50 (0.25%) + gas (~$5–$30 L1) | Batch-amortized (~$0.01–$1) | Aztec |
| Private transfer / swap inside pool | 0% protocol + gas/broadcaster | Mana/gas in batch (~$0.01–$0.50) | Aztec (usually) |
| Unshield / Withdraw $1,000 | $2.50 (0.25%) + gas | Batch-amortized (~$0.01–$1) | Aztec |
| Round-trip (shield + swap + unshield) | ~$5 protocol + high gas | ~$0.10–$3 total (batched) | Aztec |
| High-frequency small txs | Accumulates 0.50% quickly | Very low per tx due to batching | Aztec |
| Large one-off private tx | 0.50% = $500 on $100k | Still low (batch amortization) | Aztec |
| Ethereum mainnet gas congestion | Very expensive gas | L2 batching + data blobs keep low | Aztec |
Key takeaway: Aztec Network generally has the lowest fees — especially for frequent use, complex DeFi interactions, or during high gas periods — because it's a proper zk-Rollup that batches thousands of private operations, amortizing L1 costs across many users. Railgun's 0.25% per shield/unshield adds up quickly (0.50% round-trip), and being L1/L2 overlay means it pays full (or near-full) gas without batch savings.
When Railgun Might Feel Cheaper
- If you shield once, stay shielded for a long time, and do many private-to-private actions — protocol fees are 0%, only gas/broadcaster (which can be low on L2s like Arbitrum).
- For very large one-time transfers where % fee hurts less than batch-waiting on Aztec.
Bottom Line (February 2026)
Aztec wins on lowest overall fees for most realistic privacy-DeFi use cases, thanks to rollup batching and scaling. Railgun's fixed 0.25% model is predictable but more expensive on entry/exit — better suited for users who value real-time execution and broad token/NFT support over minimal cost.
Both are excellent — choose based on your priorities:
- Lowest fees + programmable private apps → Aztec
- Fast real-time privacy on existing DeFi → Railgun
Data & estimates as of February 2026. Not financial advice — always verify current fees on official docs (railgun.org / aztec.network).
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