IANA Top-Level Domains (TLD) Directory
IANA Top-Level Domains (TLD) Directory: shows bundled examples and an authoritative registry link; it does not contain or query the changing root-zone database.
About this iana top-level domains (tld) directory
IANA Top-Level Domains (TLD) Directory — browser-based utility.
How this tool works
Implements client-side IANA Top-Level Domains (TLD) Directory operations. Shows bundled examples and an authoritative registry link; it neither contains nor queries the changing root-zone database.
- URL & Header Semantic Parsing: Ingests raw URLs or Cache-Control header tokens, validating syntax against RFC 3986/9110 specifications.
- Cache-Hierarchy Evaluation: Models browser cache vs CDN shared cache behaviors (evaluating max-age vs s-maxage and revalidation flags).
- Port & Protocol Lookup: Matches numeric ports to standard IANA assignments (e.g. 443 for HTTPS, 22 for SSH, 53 for DNS, 3306 for MySQL).
- Diagnostic Reporting: Visualizes cache expiration timelines and highlights conflicting caching headers (such as no-store combined with max-age).
Worked example
Scenario: Normalize a dotted TLD example locally.
Sample input:
Processing: Trim input, remove one leading dot and uppercase the remaining text.
Illustrative output:
Limits and verification
Flags contradictory caching directives (e.g. combining 'no-store' with any 'max-age' value). URL parser strictly enforces valid URI schemes and flags invalid percent-encoded characters.
Examples demonstrate an expected workflow; they do not prove every input or every branch of an external specification. Check important results with an independent source before using them for money, security, compliance, safety, or irreversible file changes.
Browser processing boundary
Tool input is processed by code running in the browser and is not intentionally sent to a CZOA processing API. The page can still request ordinary site assets, analytics, or advertising when those services are enabled. Browser extensions and managed-device software remain outside this tool's control.
Relevant references
These references govern or help explain the format, protocol, or calculation used here. Listing a reference does not claim certification or complete implementation of every optional feature.
- Implementation-specific browser utility or reference guide (no single governing external standard)
Content owner: CZOA Tools · Last reviewed: 2026-09-15 · Review methodology
How to use it
- Enter, paste, or select your input data into the IANA Top-Level Domains (TLD) Directory workspace controls.
- Review available parameter fields, units, formats, or options configured for your task.
- Click the action button or observe immediate live calculations rendered in your browser runtime.
- Inspect the resulting output and any diagnostic messages, then copy or download the result if needed.
Frequently asked questions
What data does this TLD page contain?+
It returns a fixed seven-item example list: COM, ORG, NET, DEV, IO, CN and DE. The result also includes the IANA root-zone database URL. It does not contain a complete top-level-domain directory, a registrar database, a WHOIS response, pricing data, or availability information.
What does the input control do?+
The page has one text area, Run locally and Load sample. It trims the input, removes one leading dot if present, uppercases the remainder and returns it as query alongside the unchanged fixed example list. The query does not filter, validate, look up, register, or otherwise alter the displayed examples.
What are the completeness and freshness limits?+
The page explicitly says its offline examples are not the complete changing root-zone database. A valid-looking suffix can be absent from the seven examples, and an example can change in the authoritative registry after this bundle was built. Use the linked IANA database for current delegation, status, policy, or complete-list questions.
What result does the worked example produce?+
In the worked example, the tool matched the independent .dev vector: query DEV, all seven exact examples, the IANA URL, and the offline/incomplete warning. That proves this local normalization and fixed response only, not live DNS resolution, registry availability, WHOIS data, registration eligibility, or current root-zone state.