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Universal Speedtest CLI collects network metadata to provide context about your connection and the test server. This information helps interpret your speed test results.

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Metadata Collection

Network metadata is fetched at the beginning of each test (main.go:45): 
meta, err := cloudflare.FetchMeta()
This makes a single HTTP request to Cloudflare’s metadata endpoint and returns information about your network and the test server. Implementation: cloudflare/meta.go:9-35

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Collected Metadata Fields

The CloudFlareMeta structure contains the following fields (cloudflare/types.go:5-19): 
type CloudFlareMeta struct {
    ASN            int    `json:"asn"`
    ASOrganization string `json:"asOrganization"`
    ClientIP       string `json:"clientIp"`
    City           string `json:"city"`
    Colo           struct {
        IATA   string  `json:"iata"`
        Lat    float64 `json:"lat"`
        Lon    float64 `json:"lon"`
        CCA2   string  `json:"cca2"`
        Region string  `json:"region"`
        City   string  `json:"city"`
    } `json:"colo"`
}

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ASN (Autonomous System Number)

Field: ASN (integer) What it is: A unique identifier assigned to your Internet Service Provider (ISP) or network operator. Example: 7922 (Comcast), 701 (Verizon), 15169 (Google) Why it matters: Identifies your network provider and can be used to research network routing and peering relationships. Display format: Formatted as AS{number} in results (e.g., AS7922)

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AS Organization

Field: ASOrganization (string) What it is: The human-readable name of the organization that operates the autonomous system. Example: "Comcast Cable Communications, LLC", "Google LLC" Why it matters: Provides clear identification of your ISP or network provider.

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Client IP Address

Field: ClientIP (string) What it is: Your public-facing IP address as seen by the test server. Format: IPv4 (e.g., "203.0.113.42") or IPv6 (e.g., "2001:db8::1") Privacy note: This is your public IP address that is visible to any server you connect to on the internet.

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Colo (Colocation) Information

The Colo structure contains information about the Cloudflare data center handling your test.

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IATA Code

Field: Colo.IATA (string) What it is: The three-letter airport code identifying the data center location. Example: "LAX" (Los Angeles), "LHR" (London Heathrow), "SYD" (Sydney) Why it matters: Indicates the physical location of the test server, which affects latency due to distance.

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Geographic Coordinates

Fields: Colo.Lat (float64), Colo.Lon (float64) What it is: The latitude and longitude of the data center. Example: Lat: 34.0522, Lon: -118.2437 (Los Angeles) Why it matters: Allows precise calculation of distance between you and the test server.

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Country Code

Field: Colo.CCA2 (string) What it is: The two-letter ISO 3166-1 alpha-2 country code. Example: "US", "GB", "AU"

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Region

Field: Colo.Region (string) What it is: The state or region name where the data center is located. Example: "California", "England", "New South Wales"

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City

Field: Colo.City (string) What it is: The city name where the data center is located. Example: "Los Angeles", "London", "Sydney" Display: This value is shown as “Server Colo” in the test results (main.go:82)

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How Metadata is Fetched

The metadata fetch process (cloudflare/meta.go:10-35): 
func FetchMeta() (CloudFlareMeta, error) {
    var meta CloudFlareMeta
    
    req, err := http.NewRequest("GET", baseURL+"/meta", nil)
    if err != nil {
        return meta, err
    }
    
    req.Header.Set("User-Agent", "Mozilla/5.0...")
    req.Header.Set("Accept", "application/json, text/plain, */*")
    req.Header.Set("Referer", baseURL+"/")
    req.Header.Set("Origin", baseURL)
    
    resp, err := defaultClient.Do(req)
    if err != nil {
        return meta, err
    }
    defer resp.Body.Close()
    
    err = json.NewDecoder(resp.Body).Decode(&meta)
    return meta, err
}

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Request Details

  • Method: GET
  • Endpoint: {baseURL}/meta
  • Headers: Mimics browser request to ensure compatibility
  • Response format: JSON

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Error Handling

If metadata fetch fails, the tool continues with the speed test but shows a warning: 
if err != nil {
    fmt.Fprintf(os.Stderr, "Warning: could not fetch network metadata: %v\n", err)
}
Speed test results will still be generated, but metadata fields may be empty or default values.

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Privacy Considerations

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What is Sent

  • Standard HTTP headers (User-Agent, Accept, etc.)
  • Your IP address (automatically included in HTTP requests)
  • No personal information or system details

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What is Received

  • Network routing information (ASN)
  • Geographic approximation based on IP
  • Test server location

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Data Storage

Universal Speedtest CLI:
  • Does not send metadata to any third-party servers
  • Does not store metadata persistently
  • Only displays metadata in test results or JSON output
Cloudflare’s privacy policy governs how they handle metadata requests. Consult Cloudflare’s privacy policy for details.

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Using Metadata in Results

Metadata appears in both human-readable and JSON output formats.

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Human-Readable Output

The metadata is displayed in the results summary: 
Server Colo:   Los Angeles
Network:       AS7922 - Comcast Cable Communications, LLC
Your IP:       203.0.113.42

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JSON Output

All metadata is included in JSON output: 
{
  "download_mbps": 125.5,
  "upload_mbps": 23.4,
  "server_colo": "Los Angeles",
  "network_asn": "AS7922",
  "network_as_org": "Comcast Cable Communications, LLC",
  "ip": "203.0.113.42"
}
Implementation: Results are compiled in main.go:72-86

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Troubleshooting

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Metadata Fetch Failure

If you see the warning “could not fetch network metadata”, possible causes include:
  • Network connectivity issues: Cannot reach Cloudflare’s API
  • Firewall blocking: Corporate firewall blocking the metadata endpoint
  • DNS resolution failure: Cannot resolve Cloudflare’s hostname
  • TLS/SSL errors: Certificate validation issues
The speed test will continue even if metadata fetch fails, but location and network information will be missing from results.

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Inaccurate Location

IP-based geolocation may be inaccurate if:
  • Using a VPN or proxy
  • Your ISP’s IP ranges are incorrectly registered
  • Using mobile data (towers may be far from registered location)
The “Colo” information indicates the test server location, not your location.

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Server Selection

Cloudflare automatically routes your request to the nearest data center based on:
  • Anycast routing
  • BGP preferences
  • Network topology
You cannot manually select a specific test server. The automatically selected server represents your typical Cloudflare connection routing.

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