Development — entry 001 of 100
Userstack
Userstack parses any User-Agent string into structured JSON — browser, engine, operating system, and device type/brand/model, plus crawler/bot detection — behind a single `access_key`-gated GET endpoint. It's an APILayer product sharing that ecosystem's billing, dashboard, and docs platform with siblings like Fixer and Currencylayer, with a free-forever tier of 100 lookups/month before paid plans start at $9.99/month for 50,000 lookups/month.
AuthenticationAPI KeySign up with the provider to obtain credentials.
HTTPSSupportedTraffic is encrypted in transit.
CORSEnabledCallable directly from browser JavaScript.
PricingFreemiumA usable free tier exists, with paid plans for more volume.
FormatsJSONResponses can be requested as JSON.
GreatAPIs Score
Score75
Authentication15/25API key required
Pricing17/20Freemium tier available
Docs14/20Documentation URL provided
Formats9/15Single response format
Freshness20/20Verified within 6 months
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<a href="https://greatapis.com/api/userstack/"><img src="https://greatapis.com/badge/userstack.svg" alt="Scored 75 on greatapis.com"></a>Auth quickstart
- Sign up with the provider to get an API key.
- Send it on every request as a header
Authorization: <key> - The exact header isn't documented — Authorization is a common default; confirm in the provider's docs.
Stored keyNo key stored
Your key is stored only in this browser (localStorage) and sent directly to the API — never to greatapis.