Why do all requests return HTTP 401 "Unauthorised"? Troy Hunt 09 August 2023 23:44 Updated Make sure you're passing the key in the "hibp-api-key" request header. The key won't work if it's passed as a query string. Refer to authorisation in the API documentation for more. Related articles Why do I keep getting HTTP 429 "Too Many Requests" when querying within the rate limit? Can I please have a subscription for free? How can I get troubleshooting support for an unexplainable problem with the API? The HIBP API is working correctly but I can't get my code to work, can you help? How can I retrieve my API key?