The era of artificial intelligence (AI) writing software code instead of humans has officially begun. The industry announced on the 21st that the release of OpenAI’s ‘Codex’ and Google’s ‘Jules’ is expected to bring significant changes to developers’ working methods.
AI Converts Natural Language to Code
OpenAI’s Codex is an AI tool that converts everyday language requests into programming code. When a developer says “create a user login function,” it instantly generates working Python code. This works like an interpreter translating Korean into English.
Codex supports the entire development process beyond code generation, including bug fixes and test execution. It can handle various programming languages including Python, JavaScript, and PHP.
The OpenAI development team explained, “Developers no longer need to worry about complex syntax and can focus solely on their ideas.” It is currently available to ChatGPT Pro and Enterprise users, with plans to expand to Plus users soon.
Google Jules Provides 24/7 Autonomous Development
Google’s Jules goes further as a completely independent AI developer. It handles coding tasks in the background while developers focus on other work. This is like having a 24/7 colleague developer join the team.
Jules is based on Google’s latest AI model, ‘Gemini 2.5 Pro.’ It autonomously handles everything from bug fixes to new feature development and test writing without human intervention. It connects directly with GitHub and performs work safely on Google Cloud virtual machines.
Jules’ distinctive feature is understanding entire projects rather than single files. It also creates audio change logs of all modifications for easy developer review.
Google’s AI team stated, “Jules handles repetitive coding tasks so developers can focus on creative and strategic work, elevating team productivity to new dimensions.”
Selection Criteria Vary by Use Case
The two AI tools each have different strengths. Codex specializes in instant code generation, making it suitable for rapid idea implementation or learning purposes. Jules, on the other hand, excels at large-scale project maintenance and repetitive tasks.
Industry experts evaluate that “Codex acts like a senior developer you can ask for help anytime,” while “Jules is like a reliable colleague you can entrust with routine tasks.”
Many development teams use both AIs strategically depending on the situation. They use Codex for rapid prototyping and Jules for code cleanup and optimization.
Key Comparison Items
Security and Verification Remain Important
Experts emphasize that caution is still needed despite the expanding use of AI coding tools. Code generated by AI must be reviewed by humans, and security-critical parts must be manually verified.
They also advise that balanced usage is important, as over-reliance on AI could lead to skill deterioration among developers.
Currently, Codex requires a paid subscription, while Jules is offered as a free public beta service with usage limitations. The industry predicts these AI tools will completely transform development methods.
