OpenAI Codex vs GitHub Copilot

OpenAI Codex vs GitHub Copilot: which AI coding assistant writes better code? Developer-focused 2026 comparison.

	OpenAI Codex Best for: Agentic coding across desktop app, CLI, IDE and cloud, plus automatic PR review	GitHub Copilot Best for: AI coding in VS Code, cloud agents, code review, model choice across vendors
Overview	OpenAI Codex is OpenAI's coding agent that writes, fixes, refactors and reviews code from the ChatGPT apps, the open-source Codex CLI, an IDE extension and Codex cloud. It is included in ChatGPT plans, with full access starting at Plus for $20 a month.	GitHub Copilot is an agentic, multi-model coding assistant that goes beyond autocomplete, offering chat, an agent mode, cloud agents, code review and a CLI, with models available from vendors including Anthropic, OpenAI, Google, xAI, Microsoft and Moonshot. It bills usage through GitHub AI Credits, with tiers running from a free plan up to individual and organization plans.
Pricing	Freemium	Freemium
Users	5M+	10M+
Advantages	✅Included in ChatGPT plans, so Plus, Pro and Business subscribers get Codex without a separate subscription ✅One agent across the ChatGPT apps, CLI, IDE extension and Codex cloud, tied to one ChatGPT account ✅Runs agents in parallel and keeps cloud tasks going after you close your laptop ✅Automatic pull request review plus GitHub, GitLab (beta), Slack and Linear integrations ✅Open-source Codex CLI (Apache-2.0) for macOS, Linux and Windows	✅Genuinely agentic: agent mode, cloud agents, chat, code review and a CLI, not just autocomplete ✅Lets you pick models from multiple vendors, including Anthropic, OpenAI, Google, xAI, Microsoft and Moonshot, per task ✅Real free tier, plus free Pro access for verified teachers and maintainers of popular open source projects ✅Deep integration with GitHub, VS Code and the wider GitHub ecosystem ✅Inline code completions and Next Edit suggestions stay included and never consume AI Credits
Disadvantages	❌Plus and Business usage is capped per five-hour window, and GPT-6.1 Sol uses the allowance fastest ❌Free and Go plans only get the lightweight GPT-6 Luna model in the desktop app ❌Heavy daily use pushes you toward Pro at $100 to $500 a month or extra credits ❌Works only with OpenAI models, unlike multi-vendor tools such as Cursor or GitHub Copilot ❌Agent changes and shell access still need careful review and permission settings	❌Usage-based AI Credits billing means cost can exceed the base subscription price once you buy additional credits beyond your included allotment, making monthly spend harder to predict for heavy users ❌Third-party agent delegation and the largest credit allowances are gated behind the pricier Pro+ and Max tiers ❌Free tier is capped at roughly 2,000 inline suggestions with limited chat and agent access and no code review or cloud agents ❌Organization (Business and Enterprise) pricing is separate from the individual tier structure and was not confirmed for this card ❌Flex credit allotments are included at no extra charge, but GitHub says the amount may change over time, so total included usage isn't guaranteed to stay fixed
Rating	…	…
Website	openai.com	github.com
	Visit →Full review	Visit →Full review

Verdict: Which Should You Choose?

Choose OpenAI Codex if…

✅ You already pay for ChatGPT Plus, Pro or Business and want Codex included rather than a separate subscription.
✅ You want one coding agent that behaves the same way across the ChatGPT apps, the Codex CLI, an IDE extension and Codex cloud, all under one account.
✅ You need a task to keep running in the cloud after you close your laptop, with a reusable environment set up per repository.
✅ You want automatic pull request review from the same agent you use for coding, wired into GitHub, GitLab, Slack and Linear.

Choose GitHub Copilot if…

✅ You want to pick the model per task from multiple vendors, including Anthropic, OpenAI, Google, xAI, Microsoft and Moonshot, instead of being locked to one provider.
✅ You want to try a genuinely agentic assistant on a free plan before committing any money.
✅ You're a teacher or a maintainer of a popular open source project and want free access to paid-tier features.
✅ You rely heavily on inline completions and Next Edit suggestions and don't want that usage eating into a capped allowance.

Frequently Asked Questions

Which is better for teams that live in GitHub and VS Code?

GitHub Copilot, since it is built directly into VS Code and the GitHub ecosystem with agent mode, cloud agents and code review in the same workflow.

Which is better for developers who want to stay on OpenAI models everywhere they code?

OpenAI Codex, because it runs the same agent across the ChatGPT apps, the Codex CLI, an IDE extension and Codex cloud, all tied to one ChatGPT account.

Can I try either tool for free?

Yes, both have free tiers: Codex offers lightweight use in the ChatGPT desktop app on Free and Go plans, and GitHub Copilot's Free plan includes a capped number of inline suggestions with limited chat and agent access.

Which tool lets me switch between AI model vendors?

GitHub Copilot does, with model choice across vendors including Anthropic, OpenAI, Google, xAI, Microsoft and Moonshot, while Codex only works with OpenAI's own models.

Do both tools review pull requests automatically?

Yes, Codex can automatically review pull requests and surface findings through its GitHub and GitLab integrations, and GitHub Copilot includes code review as part of its paid plans.