Generate Simple Web Apps Fast with Gemini API

Ever needed to whip up a quick web app prototype or a specific UI component, but didn’t want to get bogged down writing all the starter code?

Introducing InstantCoder, a free and open-source AI tool that allows you to quickly generate simple web apps from one prompt using the latest Google Gemini API.

Features

Prompt-Based App Generation: The core idea. You describe the app you want (e.g., “a simple pomodoro timer”), and it generates the code.
Gemini Powered: It hooks into the Google AI Studio API, letting you choose between different Gemini models like 2.5 Pro, 2.0 Flash, and potentially newer experimental ones as they arrive. This means it benefits from Google’s latest AI advancements.
Integrated Code Sandbox (Sandpack): This is a big plus. Once the code is generated, you get an embedded Sandpack instance. You can see the live preview of your app right there and browse the generated files (usually App.js, styles.css, etc.).
CodeSandbox Export: Directly from the Sandpack view, there’s a link to open the generated project in CodeSandbox.io. This makes it super easy to start tweaking the code or save your generated app.
Open Source: The whole thing is available on GitHub. You can see exactly how it works, modify it, or host it yourself.
Modern Tech Stack: It uses a Next.js App Router setup with Tailwind CSS for styling, generating React components. This is a pretty common and useful stack for small web projects today.

Use Cases

Rapid Prototyping: Need a quick visual mock-up of a simple app idea? Describe it and see what comes out. It’s faster than building from scratch.
Component Generation: Instead of a full app, try prompting for specific React components: “Generate a React component for a contact form with fields for name, email, and message, styled with Tailwind.”
Learning Gemini for Code: It’s a practical way to see how well Gemini translates natural language requirements into actual code. You can experiment with different prompts and models.
Quick Utility Apps: Need a basic calculator, a unit converter, a random number generator, or a simple timer? InstantCoder can often scaffold these very quickly.
Exploring UI Ideas: Describe a UI concept, maybe referencing a style like “iOS style,” and see how the AI interprets it visually using standard web tech.

How to Use InstantCoder

1. Go to the InstantCoder Hugging Face Space.

2. Type a clear description of the web app or component you want. Be specific! For example: “Create an iOS style calculator app.”

3. Select the Gemini API you want to use from the dropdown. Start with Pro for better results, or Flash for speed.

4. Click the ‘Run’ button and wait for the generation to complete. You’ll see the Sandpack preview and the code appear below.

5. If you like it, click the ‘Open Sandbox’ link to preview and edit your app in Codesandbox.

Clone and Run Locally

1. Prerequisites: Make sure you have Git and Node.js (which includes npm) installed.

2. Clone the Repository: Open your terminal and run:

git clone https://github.com/osanseviero/InstantCoder.git
cd InstantCoder

3. Set Up API Key: You’ll need a Google AI API key. Get one from Google AI Studio (https://aistudio.google.com/app/apikey). Create a file named .env.local in the project root and add your key:

GOOGLE_AI_API_KEY=YOUR_API_KEY_HERE

4. Install Dependencies:

bash npm install

5. Run the Development Server:

bash npm run dev

6. Open your web browser and go to http://localhost:3000.

7. You should see the InstantCoder interface. Use it just like the Hugging Face Space (enter prompt, select model, click run).

Pros

Speed: Great for getting initial code structure very quickly.
Ease of Use: The interface is dead simple. Prompt, pick model, run.
Gemini Power: Uses modern, capable language models for generation.
Sandpack Preview: Seeing the result instantly and browsing code is excellent.
CodeSandbox Export: Seamless transition to a proper coding environment.
Open Source: Freedom to inspect, modify, and self-host.
Good for Simple Tasks: Handles requests for basic apps and components reasonably well.

Cons

Limited Scope: Struggles with complex logic, multiple pages, or backend features. It’s for small frontend apps.
Prompt Sensitivity: The quality of the output heavily depends on how well you write the prompt. Requires some trial and error.
API Key Required (Local): Running locally means you need to manage a Google AI API key.
Potential API Costs: While there might be free tiers, heavy usage of the Gemini API can incur costs. Keep an eye on Google’s pricing.
Inconsistent Quality: Sometimes the generated code is perfect; other times, it might have bugs or need significant refactoring. It’s a helper, not a replacement for a developer.

Related Resources

InstantCoder GitHub Repository: https://github.com/osanseviero/InstantCoder – The source code and main project page.
Google AI Studio: https://aistudio.google.com/ – Where you can get your Google AI API key.
Gemini API Documentation: https://ai.google.dev/docs – Learn more about the underlying AI models.
Sandpack Documentation: https://sandpack.codesandbox.io/ – More info on the embedded code editor/previewer.
llamacoder GitHub Repository: https://github.com/Nutlope/llamacoder – The project InstantCoder was originally based on.

Frequently Asked Questions (FAQ)

Q: Is InstantCoder free to use?
A: The InstantCoder software itself is open-source and free. Running it via the Hugging Face Space is likely free within certain usage limits they set. If you run it locally, you need a Google AI API key. Using the Gemini API through that key might have costs depending on your usage and Google’s current pricing structure – always check their site for the latest details on free tiers and rates.

Q: What kind of apps can it generate?
A: It excels at small, single-purpose web applications and components, primarily using React and styled with Tailwind CSS. Think things like calculators, timers, simple data displays, form components, basic landing page sections. It’s not built for complex multi-page applications or anything requiring significant backend logic or database interaction.

Q: How good is the generated code?
A: It’s variable. For very clear, simple prompts (like the calculator example), the code can be surprisingly functional and well-structured. As prompts get more complex or ambiguous, the quality might decrease, requiring more manual debugging or refactoring.

Q: Which Gemini model should I choose?
A: Good question! Generally, Gemini 2.5 Pro tends to provide better results for more complex prompts, likely producing more coherent and functional code. However, it’s usually slower and might cost more per API call. Gemini 2.0 Flash is significantly faster and cheaper, which is great for quick iterations or simpler tasks where top-tier reasoning isn’t essential. Your best bet is to experiment with both for your specific needs.

Q: Can I change the tech stack (e.g., use Vue instead of React)?
A: Not directly through the prompt interface. InstantCoder is specifically built to generate React components within a Next.js/Tailwind framework. If you wanted it to generate code for Vue, Angular, or another stack, you’d have to fork the project on GitHub and significantly modify the underlying code generation logic and the system prompts it sends to the Gemini API.