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Tests

Speed test

The speed test measures your internet connection's throughput and responsiveness. It tests download speed, upload speed, idle latency, loaded latency, jitter, and packet loss, giving you a complete picture of connection quality.

Speed testing is useful for verifying that your ISP delivers advertised speeds, diagnosing slow connections, comparing WiFi vs. wired performance, and establishing baselines before and after network changes.

What the speed test measures

The speed test runs through several phases in sequence:

  1. Idle latency: measures round-trip HTTP latency when the connection is not under load, establishing a baseline
  2. Download: saturates the connection with parallel download streams and measures throughput (Mbps) over time
  3. Upload: saturates the connection with parallel upload streams and measures throughput (Mbps) over time
  4. Loaded latency: measures latency while the connection is under load, revealing how well your network handles concurrent traffic (often called "bufferbloat")
  5. UDP latency: measures round-trip UDP latency with jitter calculations
  6. Packet loss: measures the percentage of packets lost during the test using STUN/TURN relay probes

Reading your results

After the test completes, the results screen shows summary metrics and detailed charts.

Summary metrics

Metric

Description

Download speed

Peak sustained download throughput (Mbps)

Upload speed

Peak sustained upload throughput (Mbps)

Idle latency

Round-trip latency with no load (ms)

Loaded latency

Round-trip latency under load (ms)

UDP latency

Round-trip UDP latency (ms)

Jitter

Variation in UDP latency between packets (ms). Lower is better.

Packet loss

Percentage of packets lost during the test

Result charts

The results page includes several visualizations:

  • Throughput chart: download and upload speeds plotted over the duration of the test. This reveals whether throughput was steady or fluctuated, and shows the ramp-up pattern at the start of each phase.
  • UDP latency scatter plot (Plus): individual UDP latency measurements plotted as data points, showing the distribution of response times. Includes sample count, mean, median, and jitter statistics.
  • Geographic chart: a map showing the source (your location) and destination (test server) with connection path.

Interpreting your results

A few patterns to watch for:

  • Download much faster than upload: normal for most consumer connections. Fiber connections may be more likely to have symmetric speeds.
  • High loaded latency vs. idle latency: indicates bufferbloat. Quality of Service (QoS) settings on your router may help.
  • High jitter: inconsistent latency suggests network congestion or an unreliable connection. This affects real-time applications like video calls and gaming more than general browsing.
  • Packet loss above 0%: any packet loss degrades connection quality. Consistent packet loss points to a network hardware issue or ISP-level congestion.

WiFi sensor monitoring

If you are connected via WiFi, Novabench captures wireless signal data during the speed test:

  • RSSI: signal strength in dBm (closer to 0 is stronger)
  • Signal quality: a normalized quality percentage
  • Frequency: the WiFi band in use (2.4 GHz or 5 GHz)

This data is charted alongside your speed test results on Plus and above, helping you correlate signal quality with throughput. A speed dip that coincides with a signal strength drop confirms WiFi as the bottleneck.

Feature availability by plan

Feature

Free

Plus

Speed test (nearest server)

Yes

Yes

Regional server selection

Yes

UDP latency scatter plot

Yes

WiFi sensor charts

Yes

Cloud submission and sharing

Yes

Result tagging

Yes

Advanced results grid filtering

Yes