OpenAI Codex — AI Tool Review, Features & Pricing

About OpenAI Codex

OpenAI's AI software engineering agent, and a surface of ChatGPT rather than a separately sold product — it runs inside the ChatGPT desktop app and ChatGPT web alongside its own CLI and IDE extension, and bills against the same ChatGPT plan ladder. As of September 2026 it runs on GPT-6 Astra (released September 3, 2026) for the heaviest end-to-end work, and on GPT-6 Sol and GPT-6 Luna (released September 22, 2026) — Sol for complex coding and agentic workflows, Luna for focused, high-volume tasks. GPT-6.1 Sol, released September 29, 2026, is OpenAI's recommended pick for complex coding and agentic work in Codex, with near-Astra performance at a lower cost. The GPT-5.6 family (Sol, Terra, Luna) stays selectable during that rollout. GPT-6 Astra and GPT-6 Luna are available in the ChatGPT desktop app, ChatGPT Work on the web, the Codex CLI and the IDE extension. GPT-5.5 retired from Codex for users signed in with ChatGPT on October 14, 2026; Codex sessions that sign in with an API key, and the OpenAI API itself, can still use it. Runs multiple tasks in parallel in isolated sandboxes with your repo preloaded. Available as CLI, macOS app, IDE extensions (VS Code, Cursor, Windsurf), web interface and Slack integration. The earlier GPT-5.5-Codex scored 82.7% on Terminal-Bench 2.0 and 58.6% on SWE-Bench Pro.

It belongs to the development category (subcategory: ai-coding) within the AI Workflows tool directory.

OpenAI Codex offers a freemium model with a free tier and paid upgrades.

Editorial Review: OpenAI Codex scores 8.0/10

Our editors scored OpenAI Codex 8.0 out of 10 overall (4.0 out of 5 stars), averaged across 5 independently rated dimensions.

Pros of OpenAI Codex

• Cloud agent runs tasks in parallel sandboxes and opens PRs autonomously
• Tight integration with ChatGPT plans and the OpenAI model stack
• Handles long-running, multi-file engineering work unattended

Cons of OpenAI Codex

• Best capabilities are gated behind ChatGPT Plus/Pro/Team tiers
• Cloud-sandbox model adds setup and permission friction for private repos
• Less interactive than in-editor tools for quick one-off edits

When to use OpenAI Codex

• Delegating well-scoped tickets to an agent that returns a pull request
• Parallelizing chores — tests, refactors, bug fixes — across a codebase
• Teams already standardized on the OpenAI/ChatGPT ecosystem

The editor's take on OpenAI Codex

OpenAI Codex is OpenAI's cloud software-engineering agent that spins up sandboxed environments, works tasks in parallel, and returns pull requests. It is aimed at delegation rather than the moment-to-moment autocomplete Cursor and Copilot excel at — you hand it a task and review the PR. On GPT-6 Astra it is a genuinely capable end-to-end engineer; GPT-6.1 Sol, added on September 29, 2026 at a fifth of Astra's API price, is now OpenAI's recommended model for complex coding in Codex. A strong pick if you live in the ChatGPT ecosystem, though the most capable tiers sit behind Plus/Pro pricing.

Last evaluated August 2026 by the AI Workflows editorial desk.

Pricing & Plans

• Pricing model: Freemium
• Plan details: Codex is included across the ChatGPT plan ladder rather than sold separately: Free at $0/month for quick coding tasks and Go at $8/month for lightweight work, both with GPT-6 Luna at standard speed in the desktop app as it rolls out; Plus at $20/month for a few focused sessions a week, with GPT-6.1 Sol, GPT-6 Sol and GPT-6 Luna; Pro from $100/month, with $200 and $500 plans above it (the $500 plan adds Astra Ultrafast); and Business at $20 per user per month. Enterprise and Edu are unpriced. An API-key path bills per token instead and drops the cloud features such as GitHub code review and Slack. Usage extends flexibly with ChatGPT credits (as of October 2026).

Available Models in OpenAI Codex

• GPT-6 Astra
• GPT-6.1 Sol (Plus and higher; not Free or Go at launch)
• GPT-6 Sol
• GPT-6 Luna
• GPT-5.6 Sol
• GPT-5.6 Terra
• GPT-5.6 Luna
• GPT-5.5 (API-key sign-in only since Oct 14, 2026)

Key Capabilities

• code-generation
• agent-mode
• code-review
• task-automation
• pull-requests
• debugging

Tags & Keywords

coding, autonomous, cloud-agent, sandbox, pull-requests, multi-agent, cli, macos-app, ide-extension, agentic

How to access OpenAI Codex

Visit the official OpenAI Codex website: https://openai.com/codex/.

Find more AI tools like OpenAI Codex on our AI Tools Directory, explore complete AI Workflows that combine multiple tools, or read in-depth reviews on our AI Blog.

Workflows using OpenAI Codex

OpenAI Codex is one of the recommended tools in these step-by-step AI workflows:

• App Development Workflow — Build a functional web or mobile app using natural language and vibe coding.

Alternatives to OpenAI Codex

If OpenAI Codex does not fit your use case, these alternative AI tools in the same category may be worth comparing:

• Cursor — AI-native code editor (VS Code fork) with deep editor integration, multi-agent orchestration, and Agent Mode for autonomous cod...
• Claude Code — Anthropic's agentic command-line coding tool. Since Claude Code v2.1.280 (September 2026) its default model on Pro, Max, Team, ...
• GitHub Copilot — AI pair programmer by GitHub/Microsoft with code completions, chat-based coding assistance, and a full coding agent. As of Octo...
• Augment Code — AI coding assistant with deep codebase understanding via its Context Engine. Indexes entire repositories semantically to provid...