Civitai is the “App Store” or “GitHub” of the open-source AI art world. It is the single most important website for users of Stable Diffusion.

Unlike Midjourney or ChatGPT, which are closed systems where you just type prompts, Civitai is a repository where community members share custom-trained AI models that you can download and use.

1. Core Purpose: The Model Hub

Civitai is primarily a library of files that you “plug in” to AI software (like Automatic1111 or ComfyUI) to change what the AI knows.

• Checkpoints (Base Models): These are full AI brains. One might be trained specifically to look like 1990s anime, while another is trained solely on photorealistic oil paintings.

   

• LoRAs (Low-Rank Adaptation): These are small “add-on” files (usually 20MB–200MB). You can mix them into your generation to add a specific celebrity, character, clothing style, or art concept (e.g., “A LoRA that makes everything look like it’s made of crystal”).

   

• Embeddings & Poses: Tools to help guide the AI’s composition or fix common errors like bad hands.

2. On-Site Generation

While originally just for downloading files, Civitai now has a powerful On-Site Generator. This allows you to test the models directly on their website without needing a powerful computer or a complex local installation.

• You can select a model from the library, add a LoRA, type your prompt, and generate images right in the browser.

3. Key Terminology You Will See

• SD 1.5 vs. SDXL vs. Pony: These are different “architectures.”

  • SD 1.5: Older, faster, but lower resolution.

  • SDXL: Newer, high resolution (1024×1024), better realism.

  • Pony Diffusion: A specific, highly popular model family on Civitai known for following complex prompts extremely well (originally for anime/furry art, but now capable of everything).

  • Flux: The newest state-of-the-art model supported on the platform.

4. “Buzz” System (Currency)

Civitai uses a virtual currency called Buzz to manage on-site generation and training.

• Earning Buzz (Free): You can earn Buzz by logging in daily, posting images, or having others download your models.

   

• Spending Buzz: You spend it to generate images on their servers or to train your own LoRAs on their site.

   

• Buying Buzz: You can purchase Buzz if you need a large amount for heavy creating.

   

5. Content & Safety (Important)

Civitai is an “open” platform, meaning it hosts a wide variety of content.

• NSFW Content: Civitai is known for hosting a significant amount of NSFW (Not Safe For Work) models. However, it has a robust filtering system. You must create an account and manually toggle “Adult Content” to “On” if you wish to see it; otherwise, the site remains Safe For Work (SFW).

   

• Real Person Policy: They have recently tightened rules regarding deepfakes. Generating non-consensual images of real people is strictly monitored and restricted.

   

6. Civitai vs. Midjourney