Domain Check review
A practical open-source checker for teams that need RDAP results and self-hosted access.
Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
Domain Check is an open-source domain availability tool for developers, domain researchers, and operators who need registry-based results or want to run the service themselves. It queries registry RDAP servers directly and is available through a browser-based web UI, REST API with JSON responses, and command-line interface. The project can run as a Go binary or Docker container and is distributed under the MIT license, making it a fit for teams that value control over deployment and access methods.
Its strongest point is breadth across technical workflows without leaving the same project. Teams can perform multi-TLD checks, submit bulk requests of up to 50 domains, and use webhooks to receive notifications when watched domains become available. The category specifications also list API access, bulk upload, and CSV export. This combination suits operators who want to connect domain checks to scripts, internal tools, or monitoring processes rather than rely only on a browser interface. The web UI keeps the tool accessible for occasional searches, while the API and CLI serve repeatable workflows.
Domain Check is most appropriate for self-hosted teams that need open-source deployment, direct RDAP lookups, and programmable access. It is less suited to buyers looking for generated domain variations, since domain variations are not part of the offering, or for workflows that require bulk requests above 50 domains at a time. There are also no paid-tier distinctions to compare; the product is presented as an open-source project rather than a tiered hosted service. Choose it when deployment control and developer access matter more than a broader discovery suite or managed plan structure.
Domain Check pros and cons
- Where it wins
- Registry RDAP checks provide direct availability lookups.
- REST API, CLI, web UI, and Docker support multiple workflows.
- Bulk checks support up to 50 domains per request with webhooks.
- Where it doesn't
- Bulk requests are limited to 50 domains.
- No domain variation generation is provided.
- Self-hosting requires a Go binary or Docker container.
Domain Check fact sheet, pricing and score →
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