Http?

Is it possible to access trivia data through http? As is, http is redirected to https.

Some old applications don’t natively support https. I know it’s an issue on their end and they should add https support, however are there any drawbacks to allowing requests through http and not redirecting them?

Any request via HTTP will be automatically converted to HTTPS.

Furthermore, OpenTDB appends a HSTS Header which will tell the client to never attempt to connect to the server over HTTP, always use HTTPS.