JIT Optimizer Visualizer

Real execution! Watch V8's JIT compiler optimize code as you run it. Compare First Time vs Best Time to see actual optimization.

calculateSum()

cold
function calculateSum(arr) {
  let sum = 0;
  for (let i = 0; i < arr.length; i++) {
    sum += arr[i];
  }
  return sum;
}
Calls
0
Avg Time
0.0ms
First Time
ā€”
Best Time
ā€”
Optimization Level0%
No executions yet

fibonacci()

cold
function fibonacci(n) {
  if (n <= 1) return n;
  return fibonacci(n - 1) + fibonacci(n - 2);
}
Calls
0
Avg Time
0.0ms
First Time
ā€”
Best Time
ā€”
Optimization Level0%
No executions yet

matrixMultiply()

cold
function matrixMultiply(size) {
  // Create and multiply two NxN matrices
  const a = Array(size).fill(0).map(() => 
    Array(size).fill(0).map(() => Math.random())
  );
  // ... O(nĀ³) complexity
}
Calls
0
Avg Time
0.0ms
First Time
ā€”
Best Time
ā€”
Optimization Level0%
No executions yet
ā„ļø

Cold Code

Interpreted directly. No optimizations yet.

āš”

Warming Up

Type profiling and call frequency tracking.

šŸ”„

Hot Code

Inlining, type specialization applied.

šŸš€

Optimized

Native machine code. Maximum performance.

ā— JIT Compiler Console

Waiting for execution...