Watch older strams on Twitch?

Is it possible to watch streams older than 30 days afterwards on Twitch?

Maybe. It depends on how long ago the stream was, what the streamer has set and what status the streamer has. Usually, however: no.

The streamer can set on Twitch whether transmissions should be saved automatically. If this is activated, the transmissions are saved for up to 14 days. For partners as well as Turbo and Prime users, the period is 60 days.

After this period of 14 days or 60 days, the previous transmission is deleted and is no longer available.

If you want to make previous transmissions available, you have to save the transmission manually and upload it as a video to Twitch. (However, video uploads are only available for partners and affiliates.)

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As a rule, if the streamer has activated the corresponding option, the transmissions are only available for up to 14 days (or up to 60 days). After that no more.