You can’t reliably do that in the normal Twitch chat experience. Twitch may delay or partially hide viewer lists, but there isn’t a built-in “invisible mode” that lets you chat while guaranteeing you won’t appear to others or the channel’s chat list.

What is possible

  • Chat privately instead: Twitch supports whispers, which are one-on-one messages and do not show up in public chat. You can send them with /w username.
  • Hide chat from your view: You can collapse or hide the chat panel, but that only affects what you see, not whether you appear to others.
  • Some extensions may hide message display locally: Tools like chat-filter extensions can hide certain users’ messages from your own screen, but they do not make you anonymous to Twitch or other viewers.

Important limitation

If your goal is to participate in public chat without being listed as present, Twitch does not offer a dependable official feature for that. Reports from users indicate the member list is not perfectly real-time, so someone may appear to disappear later, but that is just Twitch’s delayed updating, not true invisibility.

Best practical option

If you want to interact without drawing attention:

  1. Use whispers for private messages.
  1. Use a throwaway or secondary account if the channel allows it, while following Twitch’s rules.
  2. Avoid relying on “anonymous chat” claims from third-party tools, since they can be inconsistent or outdated.

TL;DR: Twitch chat invisibility is not a reliable built-in feature; whispers are the cleanest private alternative.