domain-check

domain-check is a CLI tool for checking domain name availability across over 1,300 top-level domains using RDAP and WHOIS protocols. It queries domain registration status through RDAP (Registration Data Access Protocol) with automatic WHOIS fallback when needed, leveraging IANA bootstrap discovery for comprehensive TLD coverage.

The tool includes domain generation capabilities through pattern expansion (\w for letters, \d for digits, ? for either), prefix/suffix permutations, and bulk processing from files. It can check up to 100 domains concurrently and offers multiple output formats including JSON, CSV, and a structured pretty mode with grouped results. Smart presets cover common use cases like startup (com, io, ai, tech), enterprise (com, org, net), and tech-focused (io, ai, dev) TLD combinations.

Developers, entrepreneurs, and domain researchers can use domain-check for brand protection monitoring, startup name exploration, and automated domain availability checking in CI/CD pipelines. The tool supports configuration files, environment variables, and includes a Rust library (domain-check-lib) for integration into other applications.

Installation

# via Homebrew
brew install domain-check

# via Cargo
cargo install domain-check