Userstack
Userstack — free tier with API key
Userstack exposes a free-tier JSON API. Register for an API key if required; we verified a public or demo endpoint.
GET https://api.userstack.com/detect
{
"success": false,
"error": {
"code": 101,
"type": "missing_access_key",
"info": "You have not supplied an API Access Key. [Required format: access_key=YOUR_ACCESS_KEY]"
}
}curl "https://api.userstack.com/detect"const res = await fetch("https://api.userstack.com/detect");
const data = await res.json();
console.log(data);import requests
res = requests.get("https://api.userstack.com/detect")
print(res.json())/detectPROBEDUserstack — free tier with API key
/detect?limit=5Paginated variant with limit parameter.
/detect?${querystring.stringify(querySearch results filtered by query parameters.
We probe a documented GET and expect 2xx JSON — full uptime and health score. Export includes every documented route below.
Stable. No schema drift observed since monitoring began — the response shape has not changed under our checks.
Userstack: common questions
Is Userstack free to use?
Yes — Userstack is a free developer tools API. Free tier: Free tier — API key required. Whether the free tier allows commercial use is unclear — check the provider docs.
Does Userstack need an API key?
Yes — Userstack needs a free API key, which you pass on each request. Rate limits: Unpublished.
Can I call Userstack from the browser?
Yes — Userstack returns CORS headers over HTTPS, so front-end code can fetch it directly with no backend proxy. Use the fetch snippet on this page, or hit "Run live" to try it now.
Is Userstack up right now?
As of our last scheduled check, Userstack is healthy with 99.02% uptime over 90 days and a 443 ms median response. We re-probe it every sweep — the status badge and uptime chart above always show the latest.