Codex
OpenAI's always-on coding agent, bundled into ChatGPT with no separate subscription — CLI, IDE, cloud tasks and automatic code review across GPT-5.x model tiers.
Verified against: learn.chatgpt.com as of 2026-09-30
Quick verdict: Codex is the pick for developers who already live in ChatGPT and want the strongest cloud-coding surface — code review, Slack automation and larger VMs — without a separate bill. The $20 Plus floor is the cheapest capable entry, Pro 5x ($100) and 20x ($200) unlock sustained heavy use. Choose Claude Code for a terminal-first workflow and a real API-only token path, Manus for autonomous goal-driven tasks, Muse for consumer personal-agent runs, and Perplexity Computer for research-to-action pipelines.
- Our rating: 4.4/5
- Strongest dimension: Functionality (4.6/5, research only)
- Weakest dimension: Localization (3/5, research only)
- Pricing: Free plan
- Verification: Research-only pass over official sources, last checked 2026-09-30. Sources: learn.chatgpt.com
Codex pricing details
- Free plan available
- no paid tier
- plus $20 / Pro 5x $100 / Pro 20x $200 (Codex bundled, no separate plan)
In our index: Bundled into ChatGPT: Free $0 (time-boxed trial) · Go $8 (no Codex) · Plus $20 (full) · Pro 5x $100 · Pro 20x $200 · Business $20/user/mo annual ($25 monthly) · Enterprise contact sales · API key: per-token, no cloud features
How Codex scores across our 6 index dimensions
- Functionality: 4.6/5 (research only)
- Usability: 4.4/5 (research only)
- Stability: 4/5 (research only)
- Collaboration: 4.3/5 (research only)
- Localization: 3/5 (research only)
- Value: 4.2/5 (research only)
Score rationale: Highest raw capability ceiling (GPT-5.x coding models, cloud VMs, auto code review) but the weakest free tier in this class — the free entry is a time-boxed promo trial, not a standing free plan. Pricing cross-checked on the official ChatGPT/Codex pricing page (redirect target of developers.openai.com/codex/pricing, learn.chatgpt.com/docs/pricing) 2026-09-30. Mapping note (2026-10-05): ease 4.4 derives from the bundling model — no standalone subscription, onboarding reduces to existing ChatGPT usage; localization 3.0 is a research-derived deduction, not a free-tier carryover — the official page marks several Codex features as region-limited (Limited*) and the CLI/IDE surface is English-first; no dedicated localization evidence was available, so the score reflects platform regional availability, not language support.
What Codex does well
- No separate subscription to manage — Codex capability ships inside the ChatGPT plan you already pay for
- Broadest cloud-agent surface: web, CLI, IDE extension, iOS, automatic code review and Slack integration on Plus and up
- Clear scaling path: 5x (Pro $100) and 20x (Pro $200) rate-limit multipliers for all-day and 7x24 automation
Where Codex falls short
- No standing free agent tier — the Free entry is a time-boxed promo trial, not a free plan you can rely on
- Go at $8/mo does not include Codex, so the usable floor is effectively Plus at $20/mo
- Usage limits are model- and task-dependent estimates, not fixed message counts, which makes budgeting harder than per-seat tools
How Codex compares to other Personal AI Agents tools
Our index tracks 4 Personal AI Agents tools. Codex sits at 4.4/5, with plus $20 / pro 5x $100 / pro 20x $200 (codex bundled, no separate plan). Here are the 3 closest alternatives we hold pricing and scoring evidence for.
- Perplexity Computer — 4.3/5 · No free plan · $200/mo (Max, for recurring Computer credits)
Perplexity Computer is an always-on digital worker that executes multi-step workflows (research, coding, documents, app actions) across 19 frontier models in an isolated cloud sandbox, billed through Perplexity Max at $200 a month. - Meta Muse — 4.2/5 · Free plan · $20/mo (Power)
Meta Muse is the consumer personal agent: it plans and executes real work (email, travel, forms, purchases) on Meta's own Muse Spark model, free up to 100M tokens a week, Power $20 and Maximum $100 for more weekly budget. - Manus — 4.0/5 · Free plan · $20/mo (Starter)
Manus is a hosted autonomous agent that plans and runs multi-step work (research, slides, spreadsheets, web apps) in its own sandboxed virtual computer, free with 300 daily-refresh credits and paid plans from $20 a month.
Frequently asked questions about Codex
How much does Codex cost?
Free plan available; no paid tier; plus $20 / Pro 5x $100 / Pro 20x $200 (Codex bundled, no separate plan). Figures verified 2026-09-30.
Does Codex have a free plan?
Yes. Codex has a free tier and no paid tier is listed.
What is Codex rated in our index?
Codex sits at 4.4/5 in our index, strongest on functionality (4.6/5, research only) and weakest on localization (3/5, research only). Codex is the pick for developers who already live in ChatGPT and want the strongest cloud-coding surface — code review, Slack automation and larger VMs — without a separate bill. The $20 Plus floor is the cheapest capable entry, Pro 5x ($100) and 20x ($200) unlock sustained heavy use. Choose Claude Code for a terminal-first workflow and a real API-only token path, Manus for autonomous goal-driven tasks, Muse for consumer personal-agent runs, and Perplexity Computer for research-to-action pipelines.
What are the drawbacks of Codex?
No standing free agent tier — the Free entry is a time-boxed promo trial, not a free plan you can rely on Go at $8/mo does not include Codex, so the usable floor is effectively Plus at $20/mo Usage limits are model- and task-dependent estimates, not fixed message counts, which makes budgeting harder than per-seat tools.
What does Codex do well?
No separate subscription to manage — Codex capability ships inside the ChatGPT plan you already pay for Broadest cloud-agent surface: web, CLI, IDE extension, iOS, automatic code review and Slack integration on Plus and up Clear scaling path: 5x (Pro $100) and 20x (Pro $200) rate-limit multipliers for all-day and 7x24 automation.
How was Codex verified?
Research-only pass over official sources, last checked 2026-09-30. Sources: learn.chatgpt.com.
What are the alternatives to Codex?
We track Claude Code (Anthropic), Meta Muse, Manus, Perplexity Computer as the closest alternatives in our Personal AI Agents index, and 4 head-to-head comparisons against Codex are available.