Do I have to upload my recordings to

If your record with:

asciinema rec

(omitting the filename argument), then, after asking for confirmation, the
resulting asciicast is uploaded to (which is a default asciinema-server instance).

However if you record with:

asciinema rec demo.cast

then the recording is saved to a local file in asciicast format.

You can now replay it directly in your terminal with:

 asciinema play demo.cast

At this point you have several options if you want to share it.

First, if you want to host it at then just run:

asciinema upload demo.cast

You can watch the recording there and share it via secret (default) or public URL.

If you’d rather host it yourself you have following options: