runs-on.dev

Free subdomains for developers. Claim yourname.runs-on.dev in seconds, then point it wherever you like.

Claim a name  ·  Quickstart  ·  Guides  ·  Records  ·  Policy

Claiming a name writes one file to this repository. That file is the record. It is the only thing that makes the name resolve, and you can read it without asking anyone.

{
  "name": "yourname",
  "owner": { "github": "yourname" },
  "claimedAt": "2026-01-01T00:00:00.000Z",
  "records": {}
}

There is no hidden database. The registry is this directory, the history is the git log, and the rules are in lib/.

Why this exists

A real top-level domain means an ICANN application. The 2026 round's evaluation fee alone is $227,000, before you've built or run a registry to back it. That's not a plausible way to get a custom-looking address for a side project.

runs-on.dev gets the same feeling: a distinctive ending instead of vercel.app or github.io, for the price of one domain, about $10 a year, by giving away subdomains under it. This is a subdomain registry, not a TLD. Every name you claim lives under runs-on.dev, which Advance Labs registered and is responsible for. Saying that plainly, instead of dressing it up as something bigger, is the whole basis for trusting it. There's prior art doing exactly this: is-a.dev, js.org, eu.org.

Claim a name

Go to runs-on.dev, sign in with GitHub, and type the name you want. If it's available, claiming it writes a record to domains/.json in this repo, as shown above, and the name is live within seconds. One name per GitHub account. See docs/claiming.md for eligibility rules, the per-account limit, and why they exist.

Point it at your own hosting

By default a claimed name serves a small profile card built from your GitHub account. To point it at your own site, forward email, or a plain redirect instead, there are two ways to change its record.

From the site. Sign in and open runs-on.dev/manage. Pick a record type, fill it in, and save. That writes a commit to domains/.json in this repository, exactly as a merged pull request would, and DNS follows within seconds. The form offers the record types in the combinations DNS actually permits, so it cannot build a record the schema would reject.

By pull request. Still supported, and the right choice when you want the change reviewed before it lands:

1. Fork this repo.
2. Edit domains/.json, adding a record under records (and

1. Open a pull request. CI validates the change against

Both paths enforce the same rules, from the same code in lib/edit.js: only the owner may change a record, and owner, claimedAt, and name are immutable once set.

| Type | Shape | Coexistence | | --- | --- | --- | | CNAME | a hostname string | Alone: cannot sit next to A, TXT, or MX. | | A | 1+ IPv4 addresses | With TXT, MX. | | TXT | 1+ strings, up to 255 chars each | With A, MX. | | MX | 1 to 5 { priority, value } entries | With A, TXT. | | URL | one absolute http(s):// string | Alone: cannot sit next to anything, not allowed under subdomains. |

Nine hosting providers, a URL redirect, email forwarding, a Bluesky handle, and Discord verification, each with the exact record to copy, are in docs/guides.md. The same walkthroughs render on the site at /docs/guides/ with more detail per provider; the markdown file is the compact version for reading here.

Once a name serves your own site, docs/seo.md covers what changes when that site lives on a subdomain: robots.txt and sitemaps are per host rather than per domain, redirect names cannot rank, and a name needs its own Search Console property.

"records": { "CNAME": "<hash>.vercel-dns-017.com" }

"subdomains": {
  "_atproto": { "TXT": ["did=did:plc:abc123"] }
}

Built on runs-on.dev

Overlap — finds meeting times for people spread across time zones. Share one link, everyone sets their hours once, and the page shows when you can all meet, with sleep treated as a hard constraint rather than as free time. Open source, AGPL-3.0: zordhalo/overlap. Write-up: the first thing built on runs-on.dev.

It runs on a claimed name like any other, which is the point: domains/overlap.json is an ordinary record, and the name resolved with a valid certificate before any DNS was configured for it.

If you build something on a name from here, open a PR adding it to this list.

How it works

A single wildcard *.runs-on.dev DNS record points every possible subdomain at one Vercel project, so an unclaimed or record-less name still resolves with a valid HTTPS certificate and gets served the profile-card page. Claiming a name is therefore a git commit, not a DNS write. Pointing a name at your own hosting merges a record into domains/.json, and a GitHub Actions workflow pushes that exact record to Vercel's DNS API on merge, which then takes priority over the wildcard for that one name. More detail, including the two write paths and the token split, in docs/architecture.md.

The rules

Everything CI checks on a domains/** pull request, so you can verify a PR yourself before opening it:

• One file per pull request.
• The path must match domains/.json, matching

• Renaming a record is refused outright. Claim a new name instead.
• owner and claimedAt are immutable once set; only the recorded owner

• New names may be claimed either on the site or by pull request. Both

• An owner may delete their own record by pull request; a maintainer can

See lib/pr.js for the implementation CI actually runs, and docs/contributing.md for the full breakdown of what it checks.

npm install
npm run dev

mkcert -install
mkcert localhost

Star the registry

Every name claimed here is one commit in this repo, authored under the claimant's own GitHub account. If you have a name, you're already in the log — a star keeps the registry easy for the next person to find.

Contributing

Bug fixes, blocklist additions, and doc improvements are welcome. See docs/contributing.md for how to add to the blocklists, run the tests, and what CI checks.

npm install
npm test

License

The code in this repository is AGPL-3.0 licensed. It is a network service, so section 13 applies: run a modified copy and let other people use it over a network, and you owe those users your source. Using the registry, or claiming a name, carries no such obligation — this binds people who fork and host the software, not people who point a subdomain at their site.

Up to commit 3492bf7 the code was MIT, and that grant still stands for the code as it was then; see NOTICE.

The bundled profanity blocklist (data/reserved-words.json) is seeded from LDNOOBW/List-of-Dirty-Naughty-Obscene-and-Otherwise-Bad-Words (English list) and keeps its own CC BY 4.0 license; see data/README.md.

Credits

The idea of giving away free subdomains under one registered domain isn't new; credit to is-a.dev for the prior art, and to js.org and eu.org for more of it.

Built and operated by Advance Labs, which registered runs-on.dev and is the party responsible for what runs under it. See POLICY.md · All Advance Labs products.