Claude Code vs Codex : A realistic comparison

This video explores the current state of AI code generation by pitting Claude Code against Codex to build a complex project management web application. To test how different backends impact AI performance, the application is built six times across Convex, Supabase, and Firebase using React, Vite, and TypeScript. The experiment evaluates each output based on functional completeness, security, code quality, and generation speed using isolated Docker containers. The results highlight significant differences in how AI models handle database architecture, specifically their struggles with Firebase security rules and Supabase Row-Level Security. While Codex generates code significantly faster, Claude Code consistently produces more modular, maintainable, and strictly typed components. The video also details the challenges of automating functional evaluations using Playwright and concludes with a definitive recommendation on which backend provides the safest and most reliable developer experience when paired with AI agents. [00:00:00] Claude Code vs Codex [00:00:51] Evaluation Methodology [00:01:18] The Build Step and Tech Stack [00:04:01] Functional Evaluation Checklist [00:05:51] Automated Security Evaluation [00:07:01] Code Quality Metrics [00:08:51] Convex Generation Results [00:09:47] Supabase Generation Results [00:10:43] Firebase Generation Results [00:11:56] Security Vulnerabilities Deep Dive [00:16:00] Code Quality and Architecture Comparison [00:16:53] Generation Time and Cost Analysis [00:17:49] The Problem with Automated UI Testing [00:19:27] Final Conclusion and Best Stack for AI - Agent Benchmarks repo: https://github.com/get-convex/agent-benchmarks - Executive summary: https://github.com/get-convex/agent-benchmarks/blob/main/runs/executive-summary.md - Functional behavior checklist: https://github.com/get-convex/agent-benchmarks/blob/main/docs/functional-behaviors.md - Security adjudication: https://github.com/get-convex/agent-benchmarks/blob/main/runs/security-human-adjudication-final.md - Code quality adjudication: https://github.com/get-convex/agent-benchmarks/blob/main/runs/code-quality-human-adjudication-final.md #claudecode #codex #aiagents #supabase #firebase #convex #react #typescript #webdevelopment #softwareengineering #codequality #websecurity