No registration  ·  No API key  ·  Free

Is it down
or just you?

A single HTTP endpoint that tells you whether any domain is online. JSON responses, CORS enabled, works in any language or stack.

GET https://isdownapi.com/api/check?domain=google.com

Live Demo

Try it right now

Type any domain and hit Check — the real API call happens in your browser.

https://

API Reference

Endpoint

GET /api/check Check whether a domain is up or down

Parameters

Name Type Required Description
domain string required Domain to check, e.g. github.com

Both GET query-string and POST (JSON or form-encoded) are accepted.

Response Fields

Field Type Description
successbooleanAPI call succeeded
domainstringNormalised domain checked
statusstringup or down
http_codeint|nullHTTP response code
response_time_msint|nullLatency in milliseconds
ipstring|nullResolved IP of the domain
checked_atstringISO 8601 timestamp
errorstringOnly present when status is down

Response — site is up

JSON
{
  "success": true,
  "domain": "google.com",
  "status": "up",
  "http_code": 200,
  "response_time_ms": 187,
  "ip": "142.250.80.46",
  "checked_at": "2026-04-17T12:00:00+00:00"
}

Response — site is down

JSON
{
  "success": true,
  "domain": "unreachable-example.xyz",
  "status": "down",
  "http_code": null,
  "response_time_ms": null,
  "ip": null,
  "error": "Could not resolve host",
  "checked_at": "2026-04-17T12:00:00+00:00"
}

Rate Limits

60 requests per IP per hour. No API key needed. Limits reset automatically each window.

🔒

CORS Enabled

Call the API directly from browser JavaScript, SPAs, or any client-side code without a proxy.

🌎

HTTPS + HTTP

We try HTTPS first, fall back to HTTP — so sites without a valid certificate are still checked.

API HTTP Status Codes

CodeMeaning
200Check completed (the domain may still be down — read the status field)
400Bad request — missing or invalid domain parameter
429Too many requests — rate limit exceeded
500Server error — something went wrong on our end

Code Examples

Integrate in seconds

Copy-paste ready snippets for every major language.

shell
curl "https://isdownapi.com/api/check?domain=google.com"

Enterprise

Need more?
Let’s talk.

IsDownAPI is free for individual developers and small projects. If you need higher rate limits, SLA guarantees, dedicated infrastructure, or a private deployment, get in touch.

  • Higher rate limits or unlimited access
  • Webhook callbacks & alert integrations
  • Private / on-premise deployment
  • Custom monitoring intervals
  • Priority support & SLA