JS Performance Benchmarker
Determine the most efficient code patterns through direct in-browser performance testing.
Benchmarking runs code in the main thread. High iteration counts may cause temporary UI stutters. Use reasonable values based on code complexity.
Run a benchmark to see charts and data
Features
Ops/Sec Metrics
Calculates operations per second to provide a standardized performance score.
Side-by-Side Comparison
Directly compare multiple implementation patterns to find the fastest one.
Iteration Control
Adjust heat-up cycles and total iterations for statistically significant results.
How to Benchmark
- Enter your code implementations into Snippet A and Snippet B.
- Adjust the Iterations count. Higher counts provide more accurate averages for fast operations.
- Click Run Benchmark to execute both snippets sequentially.
- Review the Ops/sec (Operations per second) results. The "Winner" will be highlighted in primary color.
Importance of Testing
JavaScript performance can vary significantly between micro-optimizations. This tool helps you validate performance assumptions in your specific environment (Chrome V8, etc.) before shipping to production.
Safety Note
This tool uses the new Function() constructor to execute code. Only test code that you trust. The benchmarking runs entirely on your local machine and data is never sent to any server.