How I Built a Bulk Domain Availability Checker with RDAP and Automated Scoring

Description and use

The tool quickly checks up to 50 domains via RDAP and automatically scores them on five criteria, highlighting high‑value options.

Problem

Traditional WHOIS tools are slow, rate‑limited, and often blocked, making it hard to quickly find and evaluate short, brandable domains.

Outcome

The tool enables rapid bulk domain availability checks and provides an automated scoring system that identifies high‑value domains, improving the efficiency of domain acquisition.

Workflow

• Paste up to 50 domain names (one per line) into the web interface.
• Backend processes requests in small concurrent batches using curl_multi in PHP.
• Each domain is queried via RDAP; 200 OK indicates registered, 404 Not Found indicates available.
• The scoring algorithm evaluates TLD, length, pronounceability, meaning, and brand fit.
• Domains scoring 80+ are highlighted as high value and can be copied to clipboard with one click.

Evidence

Most domain tools still use standard WHOIS (Port 43). It is plain text, rate‑limits aggressively, and often gets blocked by registrars.

Source

RDAP (Registration Data Access Protocol) is the modern, ICANN-mandated replacement. It returns structured JSON and uses standard HTTPS status codes: 200 OK = Domain is registered. 404 Not Found = Domain is available.

Source

I built a tool that lets you paste up to 50 domains (one per line). Instead of firing 50 requests at once and getting rate‑limited, the backend processes them in small concurrent batches (using curl_multi in PHP).

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I wrote an algorithmic scoring system (0-100) that evaluates domains across 5 dimensions: Extension (TLD), Length, Pronounceability, Meaning, Brand Fit.

Source