// DETAILED COMPARISON

Codeium vs OpenAI Codex

Codeium and OpenAI Codex are two of the most-compared Coding tools. Codeium starts at Free and OpenAI Codex at $20/mo — and they differ in features, ratings, and the use cases they suit best. This side-by-side breakdown covers pricing, key features, the pros and cons of each, and a clear verdict to help you pick the right one.

Cd
Codeium
Codeium
CX
OpenAI Codex
OpenAI
Rating
4.5 ★
Winner4.6 ★
Price/mo
WinnerFree
$20
Free plan
Yes
No — via ChatGPT plans
API
Yes
Yes (Codex models via API)
Context size
Large (GPT-5.x-Codex models)
Languages
All
All major programming languages
Mobile app
No
No — desktop, CLI & cloud
Plugins
Yes
IDE extension & GitHub integration

Pros & cons

Cd
Codeium

Pros

  • Generous free tier
  • Fast autocomplete
  • Supports 70+ languages
  • Works in most IDEs
  • Windsurf agentic editor

Cons

  • Branding shift (Codeium to Windsurf) can confuse
  • Advanced agent features need paid plans
  • Newer than some rivals
CX
OpenAI Codex

Pros

  • Runs everywhere: desktop app, CLI, IDE and cloud
  • Parallel agents with built-in worktrees
  • Background automations (issue triage, CI/CD, alerts)
  • Code review that catches subtle bugs
  • Skills adapt it to team standards
  • Included with ChatGPT plans — no extra license

Cons

  • Requires a ChatGPT subscription; heavy parallel work realistically needs Pro at $200/month
  • Cloud environment setup takes time
  • Younger ecosystem than GitHub Copilot

The verdict

Codeium and OpenAI Codex are close competitors, but a few differences stand out. Codeium is free to start, while OpenAI Codex costs $20/mo. OpenAI Codex earns the higher user rating (4.6 vs 4.5). Codeium offers an API that OpenAI Codex lacks — important if you need integrations or automation. Codeium also includes a free plan, which lowers the barrier to trying it. Bottom line: choose Codeium if you want to spend less; choose OpenAI Codex if you want the highest-rated option.

Which one should you choose?

When to choose Codeium

Generous free AI autocomplete and chat.

Pick Codeium if you want to spend less, need API access and integrations, and want a free plan to start.

When to choose OpenAI Codex

OpenAI's agentic coding workspace: app, CLI, IDE and cloud agents

Pick OpenAI Codex if you want the highest-rated option.

Frequently asked questions

What's the difference between Codeium and OpenAI Codex?+

Codeium: Fast, free AI code completion. OpenAI Codex: Codex is OpenAI's coding agent, powered by your ChatGPT account. The biggest differences come down to price, ratings, and features.

Which is cheaper, Codeium or OpenAI Codex?+

Codeium is free to start, while OpenAI Codex starts at $20/mo.

Which has the higher rating?+

OpenAI Codex scores 4.6 versus 4.5 for the other tool.

Does Codeium or OpenAI Codex have a free plan?+

Codeium offers a free plan; OpenAI Codex does not.

Which is better for Coding?+

For Coding, OpenAI Codex is the stronger overall pick. Choose Codeium instead if you want to spend less.

Related comparisons