cfbench

cfbench is a native Rust command-line tool designed for executing speed tests on Cloudflare's edge network. This lightweight utility effectively measures key network performance metrics, including download and upload bandwidth, idle latency, jitter, and latency during active connections. Notably, cfbench is designed without a text user interface, browser runtime, telemetry services, or local databases, ensuring a streamlined performance testing experience.

Key Features

• Measures:
  • Idle latency and jitter
  • Download and upload bandwidth
  • Latency and jitter under load for downloads and uploads
  • Transferred bytes, duration, negotiated HTTP version, and raw measurement data
  • Optional metadata context, including public IP, Autonomous System Number (ASN), network organization, and edge/location info
• Offers flexibility with options to suppress metadata using --no-metadata, delivering a concise output without personal information.

Usage Examples

Conducting a speed test with cfbench can be done easily with various command-line options. Here are some usage examples:

cfbench
cfbench --ipv4
cfbench --ipv6 --no-upload
cfbench --no-loaded-latency
cfbench --no-metadata
cfbench --json > result.json
cfbench --quiet --timeout 60

Example output from cfbench will vary based on network conditions, but here’s an illustration of what users might see:

$ cfbench --no-metadata
Testing against Cloudflare edge...
[latency 1/1] 18.42 ms
[download 100 KB 1/1] 71.25 Mbps — 11.2 ms
...

cfbench 0.1.1
Target: Cloudflare edge
Protocol: IPv6 / HTTP/1.1
Metadata: disabled
Measured at: 2026-07-26T12:00:00.000Z

Idle latency: 17.86 ms
Idle jitter: 1.44 ms
Download: 742.18 Mbps
Download latency: 29.73 ms
Download jitter: 4.10 ms
Upload: 216.94 Mbps
Upload latency: 47.81 ms
Upload jitter: 7.62 ms

Downloaded: 469.0 MB
Uploaded: 296.8 MB
Duration: 24.18 s

cfbench is compatible with Cloudflare Speedtest v1.12.1, maintaining adherence to request order, payload sizes, thresholds, percentile reductions, and standardized loaded-latency rules. However, it is important to note that native Rust timing cannot precisely replicate metrics measured through browsers, establishing methodology compatibility rather than exact numerical equivalence.

For users interested in installation, cfbench provides verified package installations for various Linux distributions and allows building from source, requiring Rust 1.95 or newer. For additional details, please refer to the installation guide and compatibility documentation.

This tool is unofficial and is neither affiliated with, endorsed by, nor supported by Cloudflare.