Network Latency Test
Free online network latency test tool. Check your client-side latency by measuring Round-Trip Time (RTT) from your browser to the server. Test network latency, diagnose connection issues, and monitor performance — no install required.
Last updated: 2026-03-19
Latency Measurement
This test fetches a small resource and measures the time taken using the browser's Performance API.
Key Features
- Measures Round-Trip Time (RTT)
- Uses browser Performance API
- Test history tracking
- Real-time latency display
- Status indicators
- Free to use, no registration required
How to Use the Latency Test
- Run Test: Click "Run Latency Test" to start measuring the round-trip time.
- View Results: The current RTT will be displayed in milliseconds.
- Analyze Performance: Compare multiple test results to identify network performance patterns.
- Clear History: Click "Clear Results" to reset the test history.
Why Use This Latency Test?
Network latency testing is essential for diagnosing connection issues, optimizing web performance, and monitoring network quality. This tool provides a quick way to measure round-trip time using your browser's built-in Performance API, helping you understand your connection quality.
Frequently Asked Questions
What is Round-Trip Time (RTT)?
Round-Trip Time (RTT) is the time it takes for a data packet to travel from your browser to the server and back. It's measured in milliseconds and indicates network latency.
What is a good RTT value?
Generally, RTT under 50ms is excellent, 50-100ms is good, 100-200ms is fair, and over 200ms may indicate network issues. Values depend on your distance from the server and network conditions.
How does the latency test work?
The test uses the browser's Performance API to measure the time taken to fetch a small resource from the server. It uses cache-busting techniques to ensure accurate measurements.
Why is my RTT high?
High RTT can be caused by slow internet connection, network congestion, distance from server, or network routing issues. Running multiple tests helps identify patterns.
Can I use this tool offline?
No, this tool requires an active internet connection to measure latency to the server. It needs to fetch resources to calculate round-trip time.
Preview
