AI image prompt generator
Generate detailed prompts for AI image generation tools optimized for social media use cases.
about the ai image prompt generator
AI image tools like Midjourney, DALL-E, and Stable Diffusion can produce scroll-stopping social visuals in seconds — but only if the prompt is good. 'A nice picture for my post' gets you generic stock-photo mush; the difference between amateur and professional AI output is almost entirely in how specifically you describe subject, style, lighting, and composition.
Strong prompts follow a repeatable anatomy: a concrete subject and action, an art style or medium ('editorial photography', 'flat vector illustration', 'isometric 3D render'), lighting and mood ('golden hour', 'soft studio light'), composition notes, and the right aspect ratio for the destination — 4:5 for Instagram feed, 9:16 for Stories and TikTok, 16:9 for X and YouTube thumbnails. In Midjourney that last part is an explicit parameter like --ar 4:5; in other tools you select the output dimensions. Consistent style descriptors across prompts are also how brands keep AI visuals looking like one coherent feed.
Describe your post's topic and pick a platform and visual style, and the generator assembles a detailed, copy-ready prompt tuned for Midjourney, DALL-E, or Stable Diffusion — including the correct aspect ratio for where it will be posted. Generate the image, attach it to your post, and schedule the whole thing with PostAI.
frequently asked questions
How do I write a good AI image prompt?
Be specific across five elements: subject and action, style or medium, lighting and mood, composition, and aspect ratio. 'A ceramic coffee mug on a rustic oak desk, editorial product photography, soft morning window light, shallow depth of field, 4:5' will beat 'coffee cup photo' every time.
What aspect ratio should I use for AI images on social media?
Match the destination: 4:5 (or 1:1) for Instagram feed posts, 9:16 for Stories, Reels, and TikTok, 16:9 for X posts and YouTube thumbnails, and 2:3 for Pinterest pins. In Midjourney you set this with the --ar parameter, e.g. --ar 9:16.
Can I use AI-generated images for commercial social media posts?
Generally yes — Midjourney (on paid plans), DALL-E, and Stable Diffusion all permit commercial use of your generations under their current terms. Avoid prompting for real people, trademarked characters, or living artists' styles, and check each tool's terms since policies evolve.
want to schedule and post, not just format?
PostAI schedules to 11 platforms, includes AI content generation, and starts at $9/mo.
start free — no credit card