Gemini offers a free tier for casual users who need help with quick tasks or...

https://mighty-wiki.win/index.php/Does_Gemini_Charge_Extra_for_API_Access%3F_A_Deep_Dive_into_Real_Costs

Gemini offers a free tier for casual users who need help with quick tasks or creative brainstorming. If you require more power, the Advanced plan costs $20 per month and includes a 1 million token context window