GitHub Copilot vs OpenAI Codex
GitHub Copilot: GitHub's AI coding assistant for code completion, chat, agents and review. OpenAI Codex: OpenAI's coding agent for the terminal, IDEs, desktop app and cloud. Here is how they compare on price, free plan, platforms and the jobs each does best, from each vendor's own pages.
| GitHub Copilot | OpenAI Codex | |
|---|---|---|
| What it is | GitHub's AI coding assistant for code completion, chat, agents and review | OpenAI's coding agent for the terminal, IDEs, desktop app and cloud |
| Pricing | Free plan | Free plan |
| Free plan | Yes | Yes |
| Cheapest paid plan | $10/mo (Pro)GitHub Copilot pricing | $8/mo (ChatGPT Go)OpenAI Codex pricing |
| Free trial | None stated | None stated |
| Platforms | Web, macOS, Windows, Linux | macOS, Windows, Linux, Web, API |
| Integrations (vendor's figure) | Not stated | Not stated |
| Open source | No | Yes |
| Made by | GitHub (Microsoft) | OpenAI |
Choose GitHub Copilot if…
- The job is getting code suggestions while writing scripts or apps.
- The job is asking questions about an unfamiliar codebase.
Choose OpenAI Codex if…
- Price matters: its cheapest paid plan is $8/mo against $10/mo.
- You need to run it on your own servers or want the source code.
- You need an API to build on.
- The job is building a small feature from a plain-language description.
- The job is reviewing code changes before merging.
Still weighing it up?
If neither is quite right, GitHub Copilot and OpenAI Codex are also compared with their other rivals: Cursor vs GitHub Copilot, Claude Code vs OpenAI Codex and GitHub Copilot vs Claude Code.
What GitHub Copilot does
- Code completions and next edit suggestions
- Chat in the IDE, on GitHub.com and in GitHub Mobile
- Agent mode that edits files in the workspace
- Cloud agent and code review on paid plans
- Copilot CLI for the terminal
- Works in VS Code, Visual Studio, JetBrains IDEs, Eclipse, Xcode and Neovim
Watch out for
- The Free plan is capped at 2,000 completions per month
- Paid plans include a monthly AI credit allowance (1,500 on Pro); extra usage costs $0.01 per credit
- Cloud agent and code review are not in the Free plan
What OpenAI Codex does
- Open-source Codex CLI (Apache-2.0) for macOS, Linux and Windows
- IDE extension for VS Code, Cursor and Windsurf
- Codex desktop app
- Cloud agent (Codex Web) at chatgpt.com/codex
- Code review and fixing of issues and failures
- Sign in with a ChatGPT plan or use an API key
Watch out for
- Usage limits depend on the ChatGPT plan, the model and task size, measured per five-hour window
- Free and Go include only limited Codex access
- API-key use is billed separately at API rates
Questions
Is GitHub Copilot or OpenAI Codex cheaper?
On published entry prices, OpenAI Codex is cheaper: $10/mo (Pro) for GitHub Copilot against $8/mo (ChatGPT Go) for OpenAI Codex. What each plan includes differs, so compare the limits too.
Do GitHub Copilot and OpenAI Codex have free plans?
Both do. GitHub Copilot: 2,000 code completions per month and a limited monthly allowance of AI credits for chat and agent features; models by auto selection; agent mode and Copilot CLI included; no cloud agent or code review; no credit card required. OpenAI Codex: ChatGPT Free includes limited Codex use for quick coding tasks; Free and Go use GPT-6 Luna at standard speed in the desktop app, subject to rollout.