Free AI tools
Small, focused calculators for people building with image and video generation APIs. No sign-up required.
AI API Cost Comparison
Compare what every image and video model costs at your actual monthly volume, including the duration rounding that makes some models pricier than their per-second rate suggests.
AI Video Cost Calculator
Estimate credits and USD for a single video job before you run it, and compare models side by side at the same duration.
JSON Prompt Generator
Build a JSON prompt and the request body that carries it. Every parameter option is one the API actually accepts, so the output runs as-is.
AI Video Prompt Generator
Build text-to-video prompts with the two components image prompts lack: what moves, and how the camera moves.
Image to Video Prompt Generator
Animating a still? This one has no subject field on purpose — your start frame already has the subject, so the prompt should describe motion.
AI Image Prompt Generator
Build image generation prompts from subject, style, lighting, camera and quality. Set what you care about, randomise the rest.
Negative Prompt Generator
Assemble a negative prompt from the failure modes you keep seeing, with an honest note on when negatives do nothing at all.
Aspect Ratio Calculator
Convert any resolution to its simplest ratio, and calculate the matching width or height when you lock a ratio.