Build a working web app from scratch in one prompt: Codex vs Claude Code
In 10 minutes get two ready prototypes of the same app and pick the tool that did better
- 1.Formulate your app idea in one sentence. For example: «a habit tracker with a calendar and progress bar». Write it down - you'll send the same prompt to both tools for a fair comparison.
Pick a simple idea: a to-do list, currency converter, or mini-game. The more specific - the better the result.
- 2.Install Claude Code if you haven't yet. Open the terminal and run the installation command. After installation, run claude in your project folder and authorize via the browser link that appears in the terminal.
Claude Code runs on macOS, Linux, and Windows (via WSL). It requires Node.js version 18+. If the service is unavailable in your region - use a VPN during authorization.
Claude Code ↗About this tool - 3.Create an empty project folder, open a terminal in it, and launch Claude Code with the claude command. When the interactive prompt appears, paste the prompt below, replacing [YOUR APP IDEA] with your idea from step 1.
Claude Code will create files, install dependencies, and start the dev server on its own. Watch the terminal - it may ask for permission to run commands; answer y (yes).
Claude Code ↗About this toolPromptBuild a complete, working web app: [YOUR APP IDEA]. Use React with Vite. Create all necessary components, styles, and logic. The app should run with `npm install && npm run dev` and work in the browser immediately. Include a clean, modern UI with Tailwind CSS. Make sure there are no errors.
What this prompt doesThis English prompt asks Claude Code to build a full working web app based on your idea using React + Vite + Tailwind CSS, runnable with npm install && npm run dev. Replace [YOUR APP IDEA] with your app description. - 4.Wait for Claude Code to finish generating files and installing dependencies. Open the browser at http://localhost:5173 - check if the app works. Take a screenshot of the result and save it. Close Claude Code (Ctrl+C).
If the dev server didn't start automatically, run npm run dev manually. Note how many manual edits you had to make - that's a comparison criterion.
Claude Code ↗About this tool - 5.Now install OpenAI Codex CLI. In the terminal, run npm install -g @openai/codex. After installation, create a new empty folder for the second prototype, navigate into it, and run codex. Authorize through your OpenAI account using the link from the terminal.
Codex CLI requires Node.js 18+. You need an OpenAI account to authorize. If the service is unavailable in your region - use a VPN.
OpenAI Codex CLI ↗ - 6.In the Codex interface, paste the SAME prompt you used for Claude Code (from step 3), with the same [YOUR APP IDEA] replacement. Wait for generation to complete, run npm install && npm run dev, and open http://localhost:5173.
Codex may create files differently - sometimes through a «sandbox» mode. If it offers to apply changes - approve them.
OpenAI Codex CLI ↗PromptBuild a complete, working web app: [YOUR APP IDEA]. Use React with Vite. Create all necessary components, styles, and logic. The app should run with `npm install && npm run dev` and work in the browser immediately. Include a clean, modern UI with Tailwind CSS. Make sure there are no errors.
What this prompt doesThe same English prompt: build a full working web app with React + Vite + Tailwind CSS. Replace [YOUR APP IDEA] with the same idea from step 3 - this is important for a fair comparison. - 7.Compare the two prototypes by three criteria: 1) did it run without manual edits, 2) how clean is the interface, 3) how well the app logic matches your idea. Record the winner for each point - that's your tool of choice for future projects.
Keep both project folders - they can be useful as templates. If one of the tools failed to launch the app at all, that's also an important comparison result.
- subscriptionClaude CodeIncluded in the Claude Pro subscription at $20/mo or Claude Max at $100/mo; there are request limits depending on the plan.
- subscriptionOpenAI Codex CLIRequires a ChatGPT Plus subscription ($20/mo) or API access with pay-per-use; exact limits depend on the plan - see the OpenAI pricing page.
- freeNode.js + npmRuntime environment and package manager - free, installed once on your computer.
Why today
AI services change fast - interfaces and free limits may differ from what's described.