Internet Speed Test

Measure your internet download speed, upload speed, and latency with a browser-based speed test. Uses Cloudflare's global edge network for accurate, low-overhead measurements.

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How to Use

Measure your internet connection speed in three phases:

Click Start Test — The test begins automatically with a latency measurement. Ten small HTTP round-trips are sent to a Cloudflare Worker at the nearest edge location. Average, minimum, maximum, and jitter (mean deviation) are calculated from these samples.
Download speed measurement — Progressive file downloads of increasing size (500KB to 10MB) are fetched from the Worker. The test runs for approximately 5 seconds, with live speed updates shown on the gauge. The adaptive sizing ensures accurate results for both slow and fast connections.
Upload speed measurement — Similar to the download phase, but data is sent to the Worker. Upload payloads range from 250KB to 5MB, adapting to your connection speed.

About This Tool

How Internet Speed Testing Works

Speed tests measure throughput by transferring data between your device and a test server, then calculating the data rate. This tool uses a Cloudflare Worker as the test server — Cloudflare operates data centers in over 310 cities worldwide, so the test endpoint is typically within 50ms of your location. This proximity provides an accurate baseline measurement of your connection's raw throughput capacity.

Results are shown in Mbps (megabits per second). To convert to MB/s (megabytes per second), divide by 8. For example, 100 Mbps = 12.5 MB/s, meaning a 100MB file would take about 8 seconds to download under ideal conditions. Actual download times are typically slower due to protocol overhead, server throttling, and network congestion.

Understanding Latency and Jitter

Latency (ping) is the time for a single round-trip between your device and the server, measured in milliseconds. Under 20ms is excellent for real-time applications like video calls and gaming. 20-50ms is good for most uses. Over 100ms may cause noticeable delays in interactive applications.

Jitter is the variation in latency between consecutive measurements. Low jitter (under 5ms) indicates a stable connection. High jitter causes choppy video calls and unpredictable gaming performance, even if the average latency is acceptable. Jitter is calculated as the mean absolute deviation from the average latency across all samples.

Factors That Affect Results

Browser-based speed tests have slightly higher overhead than native applications due to TLS/HTTP framing. Wi-Fi connections add latency compared to ethernet. VPNs add encryption overhead and routing delays. Network congestion during peak hours reduces available bandwidth. For the most accurate results, close other tabs and applications, use a wired ethernet connection, and test at off-peak hours. For more network tools, see What Is My IP and DNS Lookup.

Why Use This Tool

Connection Diagnostics

Knowing your actual internet speed helps diagnose connection problems, verify that your ISP delivers the speeds you pay for, and determine if your connection is fast enough for specific activities. Streaming 4K video requires approximately 25 Mbps, video conferencing needs 3-5 Mbps, and cloud gaming demands 15-25 Mbps with low latency.

Common Use Cases

ISP verification: Compare measured speeds against your internet plan. If you pay for 200 Mbps but consistently measure 50 Mbps, contact your ISP with these results.
Wi-Fi optimization: Test from different locations in your home to identify dead zones. Compare Wi-Fi results against a wired connection to isolate wireless issues.
VPN impact: Run the test with and without your VPN to measure the performance overhead. Some VPN protocols add 10-30% overhead.
Network troubleshooting: High latency or jitter can indicate congestion, faulty hardware, or routing problems. Use alongside DNS Lookup to check DNS resolution times.

Privacy

The test generates random binary data for transfer measurements — no personal data is sent or received. The Worker endpoints do not log IP addresses, test results, or any identifying information. No cookies are set. Related tools include What Is My IP, Subnet Calculator, WHOIS Lookup, and DNS Lookup.

FAQ

How does the speed test work?

The test measures three metrics: latency (10 small HTTP round-trips to calculate average, minimum, and jitter), download speed (progressive file downloads from a Cloudflare Worker), and upload speed (progressive data uploads to the Worker). Results are shown in Mbps.

Why are my results different from other speed tests?

Speed test results vary based on the test server location, measurement methodology, and network conditions at the time of testing. This tool uses Cloudflare's edge network, so results reflect your connection speed to the nearest Cloudflare data center — which is typically closer than most other test servers.

What affects accuracy?

Browser-based tests have slightly more overhead than native apps due to HTTP/TLS framing. Results are most accurate on stable connections. Background downloads, other browser tabs, VPN overhead, and network congestion can all reduce measured speeds.

Is any data collected?

No. The test generates random data for download/upload measurements. No personal information, IP addresses, or test results are stored. The Worker endpoints respond to requests and discard everything.