JS Performance Benchmark
Online JS benchmark tool for function timing, algorithm comparison, memory usage, rendering cost, and async concurrency evaluation.
Benchmark Controls
Benchmark Config
Benchmark Code
Ready to run benchmark tests.
Performance Metrics
0ms
Average Time
0
Ops / Sec
0ms
Fastest Time
0ms
Slowest Time
Detailed Results
Run a benchmark to see detailed results here.
Execution Time Distribution
Total Time-
Standard Deviation-
Median-
Algorithm Comparison
Algorithm 1
Average Time: -
Fastest Time: -
Algorithm 2
Average Time: -
Fastest Time: -
Performance Conclusion
-
Memory Usage Trend
Initial Memory-
Peak Memory-
Memory Growth-
After GC-
First Render-
Reflow Cost-
Relayout Cost-
DOM Node Count-
Rendering Suggestion
-
Total Response Time-
Average Response Time-
Concurrent Requests-
Success Rate-
Optimization Suggestions
Benchmark History
Guide
The JS performance benchmark tool quickly evaluates function speed, algorithm differences, memory growth, DOM rendering cost, and async concurrency behavior directly in your browser.
Core Features
- Supports five benchmark modes: function, algorithm, memory, rendering, and async.
- Includes one-click presets and custom code execution for flexible testing.
- Visualizes trends with histogram, bar chart, and memory line chart outputs.
- Provides export and history replay for regression analysis and review records.
How To Use
- Choose a test mode, then load a preset or paste your own code.
- Set iterations, warmup rounds, and input size before running.
- Read metrics, detailed results, and optimization suggestions.
- Export data for team review, baseline tracking, and regression checks.
Interpretation Tips
- Start with average time, then inspect min, max, and standard deviation for stability.
- Use the same input data when comparing algorithms to avoid sample bias.
- Memory numbers vary by browser runtime, so compare trends across multiple runs.
- Rendering and async results are best used as directional signals before deeper profiling.
FAQ
- Will code be uploaded: no, all benchmark logic runs locally in your browser.
- Why results differ between runs: browser scheduling, JIT optimization, and system load can change timing.
- Why memory says unsupported: some browsers do not expose performance.memory.
- Can this replace full load testing: no, it is a fast baseline tool for development stages.
Privacy
This tool never uploads your code or benchmark data. Execution, calculations, and chart rendering all happen locally in the browser.