Troubleshooting If requests fail, run or . How to Use BuiltWith authenticates with an API key passed as the (uppercase) query parameter on every request. The base URL is . 1. Full technology profile for a domain 2. Domains using a specific technology 3. Trends API (adoption history) 4. Company lookup (firmographics) 5. Domain relationships Guidelines 1. Parameter casing matters — (uppercase) and (uppercase) are required. 2. Pick the right product — (technology profile), (domain enumeration), (history), (firmographics). 3. Free tier is narrow — lists / trends require paid plans; the basic tech…