# .invalid
> .invalid is a reserved top-level domain (TLD) intended for use in documentation and testing to indicate that a domain is intentionally non-functional or invalid. It was defined by the Internet Engineering Task Force (IETF) in RFC 2606 to prevent accidental resolution and confusion.
- URL: https://optimly.ai/brand/invalid
- Slug: invalid
- BAI Score: 15/100
- Archetype: Phantom
- Category: Internet Protocol / Technical Standard
- Last Analyzed: April 11, 2026
## Competitors
- .example (https://optimly.ai/brand/example)
- .localhost (https://optimly.ai/brand/localhost)
- .test (https://optimly.ai/brand/test)
## Buyer Intent Signals
Problems: Standard Reserved TLDs: Using officially reserved TLDs like .example or .test for documentation. | Ad-Hoc TLD Naming: Creating non-existent TLDs (e.g., .local, .internal) without official reservation. | Hardcoded Exclusion Logic: Relying on developers to correctly filter or ignore dummy data in codebases.
Solutions: What is the purpose of the .invalid TLD? | RFC 2606 reserved domains | buy .invalid domain | is .invalid a real website? | how to set up .invalid email address