Standardwaste I tried this but it says voice search isn't available. I have gsf installed.
It only works with network access.

    klausthefish If you give Gboard network access, and then enable "Faster voice typing" in Gboard's settings, it will download the necessary components for offline speech recognition in the background. You can then disable network access in Gboard and voila! Voice typing in Gboard without network perms!

    This also works with Google speech services for apps that use it.

      I find that gboard speech-to-text only works offline in very specific circumstances. I was able to get English (US) typing to work once, but only if no other language was installed, which doesn't work for my needs. Another option is to use the Voice Input "keyboard" that comes with the Speech Services by Google app. It can be configured in Settings > System > Languages and Input > Voice Input . I was able to get this working offline more reliably than gboard's built-in voice input after downloading the language model.

      I figured out why it wasn't working.
      I used google speech services but downland the UK English because the US one wouldn't download so I had to switch the keyboard to UK English to get it to work.
      Thanks to everyone who responded.

        5 months later

        klausthefish i was directed here by someone i asked about STT ( Speech to Text). Im NOT tech savy at all. Can someone PLEASE tell me the best option so i can have STT as i text often and its easier to talk and let it write the text. I need a simple Step , 2, 3 instructions as i simply dont know what to do. THANKS !

          The two main FOSS TTS and STT apps are Kõnele and RHVoice. Kõnele requires you to have a server set up to run it but does include a keyboard for speech to text. RHVoice is a text to speech module and works great with OSMAnd+