Claude Code Prompt Builder

A free, browser-based tool. Runs entirely in your browser — no sign up, nothing stored.

100% FreeRuns in your browserbeginner

How to use this calculator

Describe the build

Task — what should it do?

Project typeFramework / stack

Files / routes in scope (one per line)Hard rules (one per line)Acceptance criteria (one per line)Style notes (optional)

Browser-only (no server)Don’t duplicate existing tools

Your Claude Code prompt

Copy-ready prompt

# Task
[Describe the change you want]

# Hard rules (do not break)
- Do NOT duplicate existing tools/components — search first and reuse or extend.
- Browser-only — no backend, API routes, database or server compute.

# Acceptance criteria
- [List what must be true for this to be done]

# Before you finish
- Build/typecheck/lint pass with no new errors
- No existing functionality broken
- No server/API code was added
- Changes are minimal and match the surrounding code style

A structured template built from your inputs — paste it into Claude Code. Runs in your browser; nothing is uploaded.

How to use this calculator

Describe the task and (optionally) the project type, framework and the files in scope.
Add any hard rules and acceptance criteria, one per line.
Keep the browser-only and no-duplicate guards on if they apply.
Copy the generated prompt and paste it into Claude Code.

How it works

A great build prompt is specific about scope, constraints and what 'done' means. This tool assembles your inputs into a structured prompt with clear sections — Task, Context, Files in scope, Hard rules, Acceptance criteria and a finish checklist.

The guards add the two rules that prevent the most rework: stay browser-only (no server) and don't duplicate existing code. It's a template — it doesn't write the code or contact an AI.

Worked example

“Add a tip calculator”. Tick browser-only and no-duplicates, list the files and two acceptance criteria, and you get a prompt that scopes the work, names the rules and ends with a build/typecheck/no-regressions checklist.

Frequently asked questions

Does this use AI or send my prompt anywhere?

No. It runs entirely in your browser using rule-based checks — your prompt is never uploaded or sent to any AI model. Still, avoid pasting passwords, API keys or private data into any tool.

Will this write the code for me?

No — it writes the prompt. Paste the result into Claude Code (or another AI coding tool) to do the actual build.

Related tools

Tip: Enter any known values to calculate the remaining results.

All calculations run in your browser. Your inputs are never saved or transmitted.