Profiling Transactions

This guide shows you how to profile Aztec transactions to understand gate counts and identify optimization opportunities.

Prerequisites

• aztec command installed (see installation)
• aztec-wallet installed
• Aztec contract deployed and ready to test
• Basic understanding of proving and gate counts

Profile with aztec-wallet

Use the profile command instead of send to get detailed gate counts:

# Import test accounts
aztec-wallet import-test-accounts

# Deploy your contract
aztec-wallet deploy MyContractArtifact \
  --from accounts:test0 \
  --args [CONSTRUCTOR_ARGS] \
  -a mycontract

# Profile a function call
aztec-wallet profile my_function \
  -ca mycontract \
  --args [FUNCTION_ARGS] \
  -f accounts:test0

Reading the output

The profile command outputs a per-circuit breakdown:

Per circuit breakdown:

  Function name                          Time           Gates         Subtotal
--------------------------------------------------------------------------------
 - SchnorrAccount:entrypoint            12.34ms         21,724         21,724
 - private_kernel_init                  23.45ms         45,351         67,075
 - MyContract:my_function               15.67ms         31,559         98,634
 - private_kernel_inner                 34.56ms         78,452        177,086

Total gates: 177,086 (Biggest circuit: private_kernel_inner -> 78,452)

Key metrics:

• Gates: Circuit complexity for each function
• Subtotal: Accumulated gate count
• Time: Execution time per circuit

Profile with aztec.js

const result = await contract.methods.my_function(args).profile({
  from: walletAddress,
  profileMode: "full",
  skipProofGeneration: true,
});

// Access gate counts from execution steps
for (const step of result.executionSteps) {
  console.log(`${step.functionName}: ${step.gateCount} gates`);
}

// Access timing information
console.log("Total time:", result.stats.timings.total, "ms");

Profile modes

• gates: Gate counts per circuit
• execution-steps: Detailed execution trace with bytecode and witnesses
• full: Complete profiling information (gates + execution steps)

Set skipProofGeneration: true for faster iteration when you only need gate counts.

Generate flamegraphs with noir-profiler

For deeper analysis of individual contract functions, use the Noir profiler to generate interactive flamegraphs. The profiler is installed automatically with Nargo (starting noirup v0.1.4).

# Compile your contract first
aztec compile

# Generate a gates flamegraph (requires bb backend)
noir-profiler gates \
  --artifact-path ./target/my_contract-MyContract.json \
  --backend-path bb \
  --output ./target

# Generate an ACIR opcodes flamegraph
noir-profiler opcodes \
  --artifact-path ./target/my_contract-MyContract.json \
  --output ./target

Open the generated .svg file in a browser for an interactive view where:

• Width represents gate count or opcode count
• Height represents call stack depth
• Wide sections indicate optimization targets

For detailed usage, see the Noir profiler documentation.

Gate count guidelines

Gate Count	Assessment
< 50,000	Excellent
50,000 - 200,000	Acceptable
200,000 - 500,000	Consider optimizing
> 500,000	Requires optimization

Next steps

• Writing efficient contracts - optimization strategies and examples
• Transaction lifecycle
• Testing contracts