Get started

fidelity-kit compares images from your renderer with one or more reference renderers. It creates PSNR metrics and visual difference images, then serves a viewer for the results. Your project only needs to write images into a suite directory.

Open your suite locally

With Node.js 22 or newer, run this command from a project containing a results/ directory. You can use the working example suite as a model for that directory.

npx fidelity-kit dev results

Open the URL printed by the CLI, usually http://localhost:3000. dev processes stale comparisons and watches for changes. Refresh the browser after changing an image.

Add fidelity-kit to your project

pnpm add -D fidelity-kit
pnpm exec fidelity-kit dev results

The results/ directory holds fidelity.json, scene images, and optional Markdown descriptions. Start with the suite format, then choose Docker serving or static publishing when you are ready to share the viewer. The CLI reference is generated from the command definitions at build time.