Velohost Velohost

IPv6 Checker API

Detect IPv6 DNS records, reachability, and HTTPS support for any domain.

Live diagnostics • Stateless processing • API-ready output

Last Updated: 01 April 2026

The Velohost IPv6 Checker API provides a programmatic way to determine whether a domain supports IPv6 networking.

It inspects DNS records, validates IPv6 reachability, and checks whether HTTPS is available over IPv6.

Base API URL

All endpoints listed below are relative to this base URL.

Base API URL https://api.velohost.co.uk/ipv6-checker/

Rate Limiting

This API is protected by a global rate limit to ensure fair usage and platform stability.

  • Limit: 30 requests per 10 seconds per IP address
  • Burst traffic is allowed
  • No authentication required
  • Requests exceeding the limit return HTTP 429

This limit applies across all Velohost public APIs.

Error responses

The API uses standard HTTP status codes to indicate errors.

429 Too Many Requests

Returned when the global rate limit is exceeded.

{
  "detail": "Rate limit exceeded"
}
          
400 Bad Request

Returned when the domain parameter is missing or invalid.

Endpoints

Check IPv6 support

Resolves IPv6 DNS records for a domain, verifies network reachability, and checks HTTPS availability over IPv6.

Request
GET /lookup?domain=example.com
Response
<lbrace>'<lbrace>'<rbrace>
  "domain": "example.com",
  "has_ipv6": true,
  "ipv6_addresses": [
    "2606:4700::6812:1b78",
    "2606:4700::6812:1a78"
  ],
  "reachable": true,
  "https_over_ipv6": true,
  "source": "dns_and_tcp"
<lbrace>'<rbrace>'<rbrace>

Implementation Guidance

For production use, validate input before sending requests, implement retry with exponential backoff on 429 or transient failures, and log normalized responses for trend monitoring.

Learn more

Explore the tool, documentation, and guides.