Free subdomain services compared
Last updated: September 25, 2026
Looking for a js.org or is-a.dev alternative? These are the main free subdomain services for developers and open source projects, and how they differ.
| Service | Scope | Domains | Targets | Claim flow |
|---|---|---|---|---|
| js.org | JavaScript ecosystem only | js.org | GitHub Pages (classic flow) or other CNAME hosts | Follow four steps, add a CNAME, open a pull request to the subdomain list |
| is-a.dev | Developers, mostly personal sites | is-a.dev | Many record types (CNAME, A, AAAA, TXT, MX, …) | Add a JSON file in a pull request; volunteers review |
| open-domains | Personal sites and open source projects | A community pool of domains | CNAME | Add a JSON file in a pull request |
| OpenRepos.org | Any open source project, any language or ecosystem | 7 domains — one per project | Approved hosting providers only (GitHub Pages, Cloudflare Pages, Vercel, Netlify, …) | Edit register.json in a pull request; CI validates, a maintainer merges, DNS is automatic |
How to compare free subdomain services
Features look similar on the surface; these five criteria are what actually differ between services:
- Eligibility — Who may claim: JavaScript projects only, any developer, or any open source project.
- Namespace — One shared domain or several to choose from; whether a project may hold more than one name.
- Records and targets — CNAME-only to known hosts is the smallest abuse surface; A/AAAA/MX records add flexibility and risk.
- Automation — Whether CI validates claims, ownership and badges, and whether DNS is provisioned automatically after merge.
- Stewardship — Who runs it, how names are kept, and what happens when a project is abandoned or abused.
When OpenRepos.org fits best
- Your project is open source in any language — not only JavaScript.
- You want to choose from several domains instead of a single namespace.
- You want a free, community-run service that is managed for the long term.
- You want automated validation, a status badge and DNS that is provisioned after merge.
When another service may fit better
- A JavaScript-only project may prefer js.org for its ecosystem focus.
- A personal site rather than a project may prefer is-a.dev.
- A project that needs A/AAAA/MX records needs a service that supports them; OpenRepos is CNAME-only.
Frequently asked questions
Is OpenRepos a js.org fork?
No. OpenRepos is an independent, MIT-licensed service inspired by the same idea: free subdomains for open source projects. Unlike js.org it is not limited to JavaScript — any language or ecosystem can claim.
Can a project use js.org and OpenRepos at the same time?
Technically yes, but most projects pick one canonical address. OpenRepos grants exactly one subdomain per project, on one of the seven domains.
Does OpenRepos support the same record types as is-a.dev?
No. OpenRepos creates a CNAME to an approved hosting provider and, when a provider requires it, one verification TXT record. A, AAAA, MX and wildcard records are not supported — this keeps the abuse surface small.
Which service should a JavaScript library choose?
js.org is a fine fit for a JavaScript-only project that likes its ecosystem focus. Choose OpenRepos if you want any-language eligibility, several domains to pick from, or automated validation and DNS.
Next steps
Ready to claim? Pick a name on openrepos.org with the domain picker, then follow a setup guide for your hosting provider. The claim itself happens in the register repository.