[Grammar] Preposition for website

[Jadoon 84]

I have learned prepositions for TV, radio and book i.e. on TV, on the radio and in the book. But
What is the preposition for a website?
For example,
I am registered on English Language (ESL) Learning Online - UsingEnglish.com.
I am registered at English Language (ESL) Learning Online - UsingEnglish.com. and
I am registered in English Language (ESL) Learning Online - UsingEnglish.com

Which sentence is correct?

 

[bhaisahab]

I have learned prepositions for TV, radio and book i.e. on TV, on the radio and in the book. But
What is the preposition for a website?
For example,
I am registered on English Language (ESL) Learning Online - UsingEnglish.com.
I am registered at English Language (ESL) Learning Online - UsingEnglish.com. and
I am registered in English Language (ESL) Learning Online - UsingEnglish.com

Which sentence is correct?

I would use "on" or "at". I wouldn't use "in".

 

[emsr2d2]

Or "registered with".

 

[Tdol]

It's a new area, so prepositions are not settled yet. You can expect to find differences of usage.