Codex writes code. Bilt builds native apps from scratch
OpenAI Codex is a powerful AI coding agent. But building a native mobile app requires more than code generation — you need build pipelines, simulators, and app store deployment. Bilt handles the entire mobile stack.
The mobile gap
OpenAI Codex is an excellent AI agent for writing and debugging code. But mobile app development has unique infrastructure needs that go beyond generating files.
What OpenAI Codex does well
- AI-powered code generation
- Sandboxed code execution
- Multi-file code changes
- Works with any language or framework
- GitHub-integrated workflows
What Bilt adds
- Generates complete mobile apps from prompts
- Cloud-based iOS & Android build pipelines
- iOS simulator streaming (no Mac needed)
- One-click App Store publishing
- Automatic backend & API generation
- Live device preview via QR code
Feature comparison
Built for native mobile
Prompt to app, not prompt to code
Codex helps you write code faster. Bilt takes a prompt and generates an entire working mobile app — screens, navigation, backend, and all.
iOS simulator in your browser
No Xcode, no Mac, no local setup. Bilt streams a real iOS simulator to your browser so you can test native behavior instantly.
One-click App Store publishing
Skip the complexity of signing certificates, provisioning profiles, and build configurations. Bilt automates the entire publishing pipeline.
Instant backend & APIs
Codex doesn't set up your backend infrastructure. Bilt generates databases, authentication, and APIs alongside your mobile app automatically.
“We were doing the whole design-to-code pipeline manually. Bilt just... skips the middleman. Prompt goes in, native app comes out. It's genuinely weird how much faster everything moves now.”
Roland Kriibi
CTO at Buildwill
Frequently asked questions
Build mobile apps with other tools
Skip the setup, ship the app
Codex is great for writing code. Bilt is great for generating and shipping complete native mobile apps. Use both — or let Bilt handle the whole stack.