$ Linux Command

Network

speedtest-cli

Command-line interface for internet bandwidth testing.

speedtestbandwidthnetworkinternetspeed

Additional Notes

speedtest-cli is a command-line tool for testing internet bandwidth using the Speedtest.net infrastructure. It measures download and upload speeds, latency (ping), and jitter by connecting to geographically distributed test servers. The tool was originally a Python-based unofficial client and later evolved into the official Ookla Speedtest CLI.

The official Ookla CLI (speedtest) provides more accurate results and supports the newer Speedtest.net protocol, while the older Python speedtest-cli package is open source but no longer updated. Both tools provide JSON output for scripting and automation.

Syntax

speedtest-cli [options]

Parameters

  • options: Flags that change how speedtest-cli behaves.
  • target: Optional file, device, interface, user, service, or command target when the command supports one.

Common Options

  • --simple: Show simple output (ping, download, upload only).
  • --secure: Use HTTPS instead of HTTP for the test connections.
  • --share: Generate a shareable result image on Speedtest.net.
  • --csv: Show results as comma-separated values.
  • --json: Show results as JSON.
  • --list: List all available Speedtest.net servers.
  • --server SERVER_ID: Test against a specific server by ID.
  • --mini URL: Use a Speedtest Mini server at the specified URL.
  • --source IP: Bind to a specific source IP address.
  • --timeout N: Set the timeout for each test connection in seconds.
  • --bytes: Show results in bytes instead of bits.
  • --no-download: Skip the download test.
  • --no-upload: Skip the upload test.
  • --single: Use a single connection instead of multiple concurrent connections.
  • --version: Show version information.

Examples

speedtest-cli

Run a full speed test against the closest server.

speedtest-cli --simple

Show a simplified summary of ping, download, and upload speeds.

speedtest-cli --json

Output results in JSON format (useful for scripts).

speedtest-cli --server 1234

Test against a specific server by its ID.

speedtest-cli --list | head -20

List the first 20 available test servers.

speedtest-cli --share

Run the test and generate a shareable results image.

Practical Notes

  • The official speedtest CLI by Ookla provides more accurate results than the older speedtest-cli Python package.
  • Results are displayed in bits per second (Mbps) by default; use --bytes for bytes per second.
  • Single-threaded tests (--single) produce lower speeds but better represent real-world single-connection performance.
  • Some networks throttle Speedtest traffic; results may not reflect real-world performance.
  • Firewall rules may need to allow connections on various ports for Speedtest to work.
  • The --json option is ideal for logging bandwidth metrics over time.