# Claude Code vs Codex Course: Which AI Coding Tool? — https://zero2vibecode.com/learn/ai-coding-tools Canonical URL: https://zero2vibecode.com/learn/ai-coding-tools/1-1-claude-code-vs-codex Two terminal-shaped coding agents from the two biggest labs. What actually differs is the working style they push you toward. These two get compared constantly, usually badly. Let us be precise about what is and is not different. ## What is the same Both are agents you run in a terminal, pointed at a project folder. Both read your files, propose changes, apply them, and can run commands. Both have a project-instructions file you can use to teach them your conventions. Both are made by a frontier lab and get updated fast enough that any specific claim about capability expires quickly. If you learn one, you can use the other. The workflow transfers almost completely. ## Where they actually differ **Ecosystem gravity.** Each is built by a company with its own model family, pricing structure and surrounding products. If your team already pays for one of them, that is a real and legitimate reason to pick it. **Conversation style.** The two agents feel different to work with — how much they explain, how eagerly they change things, how they respond when you push back. This is subjective and it matters more than people admit. You will spend hours talking to this thing. **Surfaces.** Beyond the terminal, each vendor ships its own mix of editor integrations, web surfaces and automation hooks. Which of those you need depends entirely on your setup. ## How to run the comparison yourself Take one real task from a project you actually have. Something bounded — a bug fix, a small feature, a rename across a few files. Then: 1. Give both agents the identical request, with the identical context. 2. Do not help either one more than the other. 3. Compare three things: did it work, did you understand what it did, and how much did you have to correct it. The third one is the sleeper. An agent that produces working code you cannot follow is worse for you, right now, than one that produces slightly clumsier code you can read. **Why there are no numbers here.** Any table of context sizes, prices or model versions would be wrong within weeks. This course teaches you what to compare; the current values belong on the vendors' own pages, and you should read them there.