Question

1. He uploaded the file on Youtube.
2. He uploaded the file onto Youtube.
3. He uploaded the file to Youtube.

4. He uploaded the file on the website.
5. He uploaded the file onto the website.
6. He uploaded the file to the website.
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Are they all grammatical?

Answer 1

Yes, They are all grammatical.

Answer 2

3 and 6 are the best.