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|3 min read

Gemini Thumbnail Creator: A Prompt for Instagram Reel Thumbnails

geminiprompt

This is the thumbnail generation prompt I use for my Instagram Reels. It is designed to produce consistent, brand-aligned thumbnails with minimal iteration.

You can find the full prompt here: Gemini Thumbnail Creator Gist

What it does

  • Generates a 9:16 vertical thumbnail
  • Places a clear human subject and brand logo
  • Uses cinematic, high-contrast colors
  • Keeps text large and readable on mobile
  • Maintains a consistent visual system across posts

How to use it

  1. 1.Copy the prompt from the gist.
  2. 2.Replace the topic placeholder with your video subject.
  3. 3.Attach your logo and any reference images.
  4. 4.Generate in Gemini's image generation mode.
  5. 5.Pick the strongest result and export.

The goal is speed with consistency. Generate two or three variants, pick the strongest, and move on. Thumbnail work should be a system, not a project.