If you want a free AI art generator that gives you daily credits without needing a credit card, Dreamlike Art is a good choice. It's based on Stable Diffusion technology for fast creation of original art, and it offers 50 daily credits that you can increase to 74 more if you want. The site also lets you queue up to 5 images and generate one image at a time with limited settings in the free tier.
Another good option is FollowFox, which offers 10 free daily image generations. It's an open-source project that lets you generate images from text prompts and tweak more than 25 parameters. FollowFox is good for creatives who want to experiment with ideas and create promotional materials without paying anything upfront.
If you want to try out AI-generated art with a bit more control, Stablecog offers a free tier that lets you generate 20 images a day. It's based on Stable Diffusion and the Kandinsky models for fast generation, and it's got a lot of options, including aspect ratio and image upload. The site also has a gallery where you can browse AI-generated images and detailed documentation on programming and credit management.