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WHOIS vs RDAP: A Comparison

Comparing the old and new protocols for domain registration data

Protocol Overview

As the internet evolves, the need for more robust and secure domain registration data protocols has become evident. Let's compare WHOIS and RDAP across key aspects to understand why this transition is happening.

Key Protocol Differences

WHOIS

  • Plain text responses
  • Port 43 based
  • No standardized format
  • Limited character support

RDAP

  • Structured JSON responses
  • HTTPS based
  • Standardized data format
  • Full Unicode support

Security & Privacy

WHOIS Limitations

  • No built-in authentication
  • All data publicly accessible
  • Vulnerable to data harvesting

RDAP Improvements

  • Built-in authentication mechanisms
  • Tiered access control
  • HTTPS encryption

Performance & Scalability

The architectural differences between WHOIS and RDAP significantly impact their performance and scalability:

WHOIS Constraints

  • • Limited query capabilities
  • • No response size limits
  • • No built-in rate limiting
  • • Single-purpose protocol

RDAP Advantages

  • • Advanced query options
  • • Pagination support
  • • Built-in rate limiting
  • • RESTful API design

Looking Ahead

While WHOIS continues to be widely used, RDAP is becoming the standard for domain registration data access. The transition is driven by:

  • ICANN's mandatory RDAP implementation for gTLDs
  • Growing need for structured, machine-readable data
  • Increasing privacy regulations worldwide
  • Modern API integration requirements

Try Both Protocols with DomainDetails.io

Compare WHOIS and RDAP responses side by side with our domain lookup tools.

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