FQDN Converter

About This Tool

The FQDN Converter constructs a fully qualified domain name from a given hostname by applying a user-specified suffix and enforcing RFC-compliant formatting. It normalizes case, validates per-label lengths, and ensures the final string conforms to DNS naming rules. It does not perform DNS lookups; its purpose is to produce a canonical string suitable for zone files, certificates, or data hygiene workflows. The tool supports optional IDN handling, enabling punycode conversion for Unicode inputs before suffix application. This makes it suitable for multilingual environments where hostnames must be stored or transmitted in a DNS-compatible form. Typical use cases include preparing DNS records, validating user-entered hostnames, or cleaning data imports prior to deployment. The unique value lies in precise RFC-aligned normalization, explicit length checks, and the ability to produce a trailing root dot when required, which helps ensure consistency across diverse DNS configurations.

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