Use Cases

Practical ways developers, DevOps engineers, and security analysts use ipfast.dev in their daily workflows.

DevOps & Infrastructure

Verify Server Egress IP

When deploying to a new cloud region or configuring a NAT gateway, you need to verify what IP your outbound traffic uses. Add a quick check to your provisioning script:

EGRESS_IP=$(curl -s ipfast.dev/text)
echo "Server egress IP: $EGRESS_IP"

Deployment Region Verification

Confirm your service is actually running in the region you deployed to. Especially useful for multi-region deployments where misconfiguration can route traffic to the wrong region:

REGION=$(curl -s ipfast.dev/country)
if [ "$REGION" != "US" ]; then
  echo "WARNING: Expected US, got $REGION"
fi

VPN / Proxy Verification

Verify that your VPN or proxy is actually routing traffic through the expected exit node. Compare the detected country and city against your expected VPN location:

curl -s ipfast.dev/json | jq '{ip, country, city}'

CI Pipeline IP Logging

Log the public IP of your CI runner for debugging firewall rules. When a deployment fails because of an IP allowlist, you'll know exactly what IP to add:

# GitHub Actions / GitLab CI step
echo "Runner IP: $(curl -s ipfast.dev/text)"

Frontend & Web Apps

Timezone Detection for Date Formatting

Detect the user's timezone to format dates and times correctly without asking them to set it manually. Uses the IANA timezone identifier (e.g., "America/New_York"):

const { timezone } = await fetch('https://ipfast.dev/json')
  .then(r => r.json());
// Use timezone for Intl.DateTimeFormat

Country-Based Content Localization

Show localized content, currency, or language based on the visitor's country. Faster than browser geolocation API and doesn't require user permission:

const country = await fetch('https://ipfast.dev/country')
  .then(r => r.text());
if (country.trim() === 'DE') showGermanVersion();

Map-Based Features

Get the user's approximate location for map centering, store locators, or nearby-content features. Returns lat/lon coordinates without requiring browser geolocation permission:

const [lat, lon] = (await fetch('https://ipfast.dev/coordinates')
  .then(r => r.text())).trim().split(',');
map.setCenter({ lat: +lat, lng: +lon });

Browser / Device Detection

Get parsed user agent data without adding a UA parsing library to your frontend bundle. Useful for analytics, A/B testing, or showing browser-specific instructions:

const ua = await fetch('https://ipfast.dev/useragent')
  .then(r => r.json());
console.log(ua.browser, ua.os, ua.device);

Security & Monitoring

TLS Configuration Audit

Verify that your HTTP client is negotiating modern TLS versions and cipher suites. Useful for security compliance checks:

curl -s ipfast.dev/connection | jq .
# Check: tlsVersion should be "TLSv1.3"

Bot Detection Verification

Test whether your automated tools are being detected as bots by user agent parsers. Useful when building scrapers, crawlers, or monitoring tools:

curl -s ipfast.dev/useragent | jq .isBot
# Returns true for curl, wget, bots

Network Latency Check

The TCP round-trip time in the /connection response tells you the network latency between your client and the nearest the edge. Useful as a quick network quality indicator:

RTT=$(curl -s ipfast.dev/connection | jq .clientTcpRtt)
echo "Network RTT: ${RTT}ms"

Header Debugging

When debugging proxy chains, CDN configurations, or header-based routing, see exactly what headers your request is sending after all intermediaries have modified it:

curl -s ipfast.dev/headers | jq .

Data & Analytics

Spreadsheet Import

The CSV endpoint returns data with a header row that you can import directly into Excel or Google Sheets. Useful for logging IP data in tabular format:

curl ipfast.dev/csv >> ip_log.csv

Config File Generation

Use the YAML endpoint to generate configuration snippets with your server's IP data. Useful for templating infrastructure configs:

curl -s ipfast.dev/yaml > server_geo.yaml