# Turn a product brief into a task-tested UI prototype: tool stack

> Prototype one three-screen journey and test it with three people before handing the design to a developer.

- Canonical: https://gptnavi.com/stacks/product-brief-to-task-tested-ui-prototype-stack
- Estimated monthly cost: Check Labs access and current generation limits; user research and implementation still require time.
- Last materially updated: 2026-10-22
- Best for: Founders and product designers

## Problems this stack solves

- New feature exploration
- MVP design handoff

## Recommended tools

### UI exploration and prototype

Recommended: Google Stitch

Why: Explore a coherent journey and produce a developer handoff.

### Task-test evidence

Recommended: Google Sheets

Why: Record actual completion and observed friction.

## Beginner setup plan

1. Write who the user is, the starting point, the action to finish, and how success is observed. Limit the first prototype to three screens and include an empty or error state.
2. Provide the brief and approved references to Google Stitch. Choose one coherent direction, align text and spacing, and connect the primary route. Use sample data and label simulated actions in the prototype.
3. Ask three intended users to complete the task without coaching. Record completion, hesitation, misclicks, and misunderstood labels. Revise the two most disruptive issues and repeat those steps.
4. Export the supported design or code artifacts and list states, responsive rules, component choices, and unresolved questions. Have a developer inspect the output and implement real data flows before release.

## Included workflows

- https://gptnavi.com/workflows/product-brief-to-task-tested-ui-prototype