Abacus
Development
Free and simple counting service. You can use it to track page hits and specific events
No keyCORSHTTPS
Userstack
Secure User-Agent String Lookup JSON API
Verified 4 days ago: 100% uptime
API key
OAuth flow
HTTPS
Supported
Browser calls
No, needs a proxy
Status
Live · 100/100
What our checks found
- Health score
- 100/100
- Reliability
- 100%
- Average latency
- 1135ms
Last checked 2026-09-18. Measured independently, not self-reported by the provider.
How to call it
A starting template for Userstack. Replace ENDPOINT with the path from the official documentation, which we link above rather than guess at.
# Uses OAuth. Exchange your credentials for an access token first.
curl -s "https://userstack.com/ENDPOINT" \
-H "Authorization: Bearer YOUR_ACCESS_TOKEN" \
-H "Accept: application/json"This API does not send CORS headers, so a browser will block a direct call from your front end. Call it from your server, or put a small proxy in front of it.
Where this listing comes from
Aggregated from one public source (public-apis), then normalised and checked by us. If something here is wrong, tell us and we will correct it.
Other Development APIs
See all 263 →API Status Check
Development
Real-time status monitoring for 270+ APIs and services
No keyCORSHTTPS
APIzone
Development
Independent uptime & status monitoring for 200+ popular APIs
No keyCORSHTTPS
Aquanode
Development
Live GPU rental prices and availability across nine cloud providers
No keyCORSHTTPS
ArulJohn.com
Development
A simple IP Address API in JSON
No keyCORSHTTPS
CDNJS
Development
Library info on CDNJS
No keyCORSHTTPS
Userstack — common questions
Answered from what our own scheduled checks found, not from the provider's marketing.
Is Userstack free to use?
Userstack is listed in our free catalogue, but it requires OAuth, so you will need to register before your first call. Providers frequently reserve higher limits and commercial use for paid plans.
Does Userstack need an API key?
Userstack uses OAuth rather than a simple key, so you register an application and complete an authorisation flow before making calls. That is more setup than a key, and it is why OAuth APIs are harder to try quickly.
Can I call Userstack from browser JavaScript?
Not directly. Userstack did not return CORS headers when we checked, so the browser will block your page from reading the response even though the request itself succeeds. Call it from a server, or put a small proxy in front of it.
Is Userstack still working?
Yes, as of 2026-09-18. Our automated check reached Userstack and recorded a 100% reliability score with a median response time of 1135 ms. We re-check on a schedule, and this page updates with the result.
Is Userstack available over HTTPS?
Yes. Userstack serves over HTTPS, so you can call it from a secure page without triggering a mixed-content block.