Network Diagnostics
Check your connection type, bandwidth estimate, RTT, and device information using the browser Network Information API.
What Do These Metrics Mean?
The Network Information API exposes several properties about your current connection. Here is what each one tells you.
| Metric | Description | Typical Values |
|---|---|---|
| Connection Type | The effective type of connection as determined by the browser, based on observed performance | 4g, 3g, 2g, slow-2g |
| Downlink Bandwidth | Estimated maximum downlink speed in megabits per second, rounded to the nearest 25 Kbps | 1.5 Mbps, 10 Mbps, etc. |
| RTT | Estimated round-trip time in milliseconds, rounded to the nearest 25 ms | 50 ms, 100 ms, 300 ms |
| Data Saver Mode | Whether the user has requested reduced data usage through a browser or device setting | Enabled / Disabled |
How Network Diagnostics Work
This tool uses the browser's built-in Network Information API to read connection details directly from your device. Unlike a traditional speed test that transfers data to measure throughput, the Network Information API provides passive estimates based on the browser's recent network activity. This means results appear instantly, with no data transfer required.
The API reports an effective connection type (such as 4g or 3g) that reflects observed performance rather than your physical connection technology. A device connected to Wi-Fi might still report 3g if the actual throughput and latency match that tier. The downlink estimate and RTT are similarly derived from real observations rather than theoretical maximums.
Browser support for the Network Information API varies. It is fully supported in Chromium-based browsers (Chrome, Edge, Opera, Samsung Internet) but not available in Firefox or Safari. On unsupported browsers, the tool will indicate which metrics are unavailable. For a comprehensive measurement of your actual download and upload speeds, use the Pong.com speed test instead.
Network Diagnostics FAQ
What is the Network Information API?
The Network Information API is a browser API that exposes information about your device's network connection. It provides details like the effective connection type (4G, 3G, 2G, slow-2g), an estimated downlink bandwidth in megabits per second, the round-trip time in milliseconds, and whether you have enabled a data saver preference. It is supported in Chromium-based browsers such as Chrome, Edge, and Opera.
What does connection type mean?
Connection type, also called effective connection type, describes the general quality of your network connection as determined by the browser. The possible values are 4G (fast broadband), 3G (moderate speed), 2G (slow), and slow-2g (very slow). This value is based on observed round-trip time and downlink measurements, not on your actual cellular or Wi-Fi technology.
What is RTT in network diagnostics?
RTT stands for round-trip time. It measures how long it takes for a small data packet to travel from your device to a server and back, expressed in milliseconds. Lower RTT values indicate a more responsive connection. The Network Information API provides an estimated RTT based on recently observed network activity in the browser, rounded to the nearest 25 milliseconds.
What does the Data Saver setting do?
The Data Saver setting is a browser or device preference that signals to websites and applications that you want to reduce data usage. When enabled, websites can respond by loading lower-resolution images, deferring non-essential resources, or compressing content. The Network Information API exposes this preference so web developers can adapt their content delivery accordingly.
Why does my estimated bandwidth differ from my speed test result?
The downlink bandwidth reported by the Network Information API is a rough estimate based on recently observed network conditions in the browser. It is rounded to the nearest 25 kilobits per second and capped at a maximum value. A dedicated speed test measures throughput more precisely by transferring large chunks of data to and from a server. The API estimate is useful for adaptive content loading but is not a substitute for a full speed test.
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