From hobbyists to startups and even large enterprises, more developers (and non-developers) are turning to AI-powered tools to write, debug, and test code at lightning speed. Whether you’re building a website, mobile app, automation script, or API, AI code builders can get you up and running faster than ever—sometimes even without writing a single line manually.
In this post, we’ll break down what AI code builders are, how they work, the best tools available today, and how you can use them in your workflow (including one for testing that many overlook!).
What is an AI Code Builder?
An AI code builder is a tool that uses artificial intelligence to help you generate code based on natural language prompts, user intent, or minimal inputs. Instead of spending hours writing boilerplate or Googling syntax, you simply tell the AI what you want—and it writes the code for you.
Some tools work inside your code editor (like VS Code), while others are browser-based, offering drag-and-drop app builders with AI-powered logic underneath. The best part? You don’t need to be a coding expert to get started.
How AI Code Builders Work
These tools are powered by large language models (LLMs) trained on billions of lines of code from public sources like GitHub. When you provide a prompt like “Create a REST API with user login functionality in Node.js,” the AI analyzes your request and generates high-quality, ready-to-use code.
Some AI code builders also include:
- Autocomplete and inline suggestions
- AI chat interfaces for debugging
- One-click deployment options
- Built-in testing and documentation
They’re like a mix of a junior developer, Stack Overflow, and a helpful co-pilot—all rolled into one.
Best AI Code Builders You Should Try
Let’s look at some of the most popular and powerful AI code builders available in 2025:
- Replit Ghostwriter
Replit is a browser-based coding platform, and Ghostwriter is its built-in AI assistant. You can start coding instantly in the browser, ask Ghostwriter questions, and get full code suggestions and explanations.
✅ Ideal for beginners
✅ Real-time AI help
✅ Works in over 50+ languages
✅ Limited free usage, paid upgrade available
- Codeium
Codeium is a free AI code builder that integrates with your favorite editors like VS Code, JetBrains, and even Jupyter.
✅ 100% free for individuals
✅ Supports 70+ programming languages
✅ Fast inline suggestions and code completions
✅ Has an AI chat inside your IDE
It’s a top pick for developers who want powerful AI without paying for GitHub Copilot.
- GitHub Copilot
This one’s the most popular AI code builder on the market, built by GitHub and OpenAI.
✅ Works inside VS Code and JetBrains
✅ Smart, context-aware suggestions
✅ Can generate full files and functions
❌ Paid ($10/month), free for students and open source contributors
Copilot is powerful and deeply integrated with GitHub, making it ideal for serious devs.
- DeepCode by Snyk
While not a traditional code generator, DeepCode helps you analyze your code in real time and fix bugs as you write.
Focuses on clean, secure code
Highlights bugs and best practices
Ideal for teams with a focus on security
Great if you want to pair AI code generation with quality and compliance.
What About Testing? Use Keploy to Auto-Generate Tests
You’ve built the code—but how do you test it?
This is where most AI tools stop short. But not Keploy. It’s a free, open-source testing platform that records your API requests and automatically creates test cases and mocks. No more writing test files from scratch.
Why Keploy is a perfect companion to AI code builders:
- Works with backend apps in Go, Java, Python, and more
- Turns real API calls into integration tests
- Easy to use, even if you’re new to testing
- Saves hours of repetitive test writing
???? Try Keploy on GitHub
With Codeium or Copilot writing your code and Keploy testing it, you’ve got a complete AI-driven development workflow.
Who Are AI Code Builders For?
You don’t need to be a senior dev to benefit from these tools. In fact, they’re great for:
- Beginners who want to learn and build fast
- Startup founders looking to prototype ideas
- Freelancers juggling multiple client projects
- Enterprise devs who want to reduce boilerplate
These tools lower the barrier to building software—making development more accessible to everyone.
Final Thoughts
AI code builders are no longer a novelty—they’re becoming essential. Whether you're building your first web app or managing a complex backend system, these tools can help you move faster and with more confidence.
Try one out. Pair it with Keploy for testing. See how much more you can get done.
The future of development isn’t about working harder—it’s about building smarter. And AI code builders are leading the way.
Read more on https://keploy.io/blog/community/best-free-ai-code-generators