Response Time Analyzer

Percentile latencies describe the distribution of response times. p50 (median) means half of requests are at or below that time. p95 means 95% of requests are that fast — 5% are slower. p99 captures your worst-case 'tail latency': 99% complete in that time, only 1% are slower. p99 is critical for user experience.

The mean is easily skewed by outliers. If 99 requests take 10ms and one takes 10,000ms, the mean appears to be ~110ms — but p99 is 10,000ms. Users experience individual requests, not averages. Always monitor p95 or p99 alongside the mean for a realistic picture of performance.

Enter one response time (in milliseconds) per line. You can paste raw numbers like 45, 120, 300. The tool accepts integers and decimals.

Standard deviation measures how spread out your response times are around the mean. A low std dev means consistent latency; a high std dev indicates unpredictable, spiky performance. High variability is often worse for user experience than a slightly higher but consistent latency.

General guidelines: under 100ms feels instant, 100–300ms is acceptable for most API calls, 300ms–1s starts to feel slow, over 1s significantly impacts user experience. Real-time features should target under 50ms.