Codex Pricing (2026): Free vs $20 Plus vs $100 Pro, with Credit Burn Rates and Real Session Costs

TL;DR

Codex comes bundled with every ChatGPT plan: Free ($0), Go ($8/mo), Plus ($20/mo), Pro from $100/mo with 5x or 20x rate-limit options, Business pay-as-you-go, and Enterprise/Edu custom. There is no standalone Codex subscription. API-key usage bills per token instead: gpt-5.3-codex costs $1.75/M input and $14.00/M output.

Limits are credit-based under the hood. GPT-5.5 burns 125 credits per 1M input tokens and 750 per 1M output tokens, and credits track API token prices at roughly 4 cents each. A typical session lands at $0.50-$2.00 in API-equivalent cost. Plus allows 15-80 GPT-5.5 messages per 5-hour window; Pro multiplies that by 5 or 20.

Every Codex Plan

Codex is included in ChatGPT Free, Go, Plus, Pro, Business, and Enterprise. The six tiers as of June 2026:

The other path is an API key with no subscription at all: usage bills at standard API token rates (covered in API Pricing below). You lose the cloud features and integrations, and keep raw model access.

The $100 Pro Tier, Explained

The change that generated the most Reddit threads: Pro no longer means $200. Pro starts at $100/month and you pick a rate-limit multiplier at checkout.

• Pro 5x, $100/mo: 5x the Plus limits. On GPT-5.5 that is 75-400 messages per 5-hour window (Plus is 15-80). On GPT-5.4 it is 100-500 (Plus is 20-100).
• Pro 20x, $200/mo: 20x the Plus limits. 300-1,600 GPT-5.5 messages or 400-2,000 GPT-5.4 messages per 5-hour window.

Both Pro options include the Codex-Spark research preview, which Plus does not. Per-message capacity pricing is identical across the two: $100 buys 5 Plus-units of limit, $200 buys 20, so the 20x option is twice the price for four times the capacity. If you hit Pro 5x limits even occasionally, the 20x upgrade is the cheaper marginal capacity.

Usage Limits and the 5-Hour Window

Codex limits reset on rolling 5-hour windows, not monthly. The published per-window message allowances:

The ranges look vague until you see what drives them: limits are enforced in credits, and message cost varies with token consumption. A GPT-5.5 message averages 5-45 credits. A one-line fix sits at the bottom of that range; an agentic run that reads thirty files and writes ten sits at the top. Divide your credit allowance by 45 for the worst case and 5 for the best case and you get exactly the published 15-80 spread.

When a window is exhausted you either wait for the rolling reset (5 hours after the usage that consumed it) or buy additional credits from Codex Settings > Usage > Credits, available on Plus and Pro.

Credit Burn Rates Per Model

OpenAI publishes exact credit burn rates per million tokens. This is the table that lets you predict costs instead of guessing:

Cross-reference these against API prices and the conversion falls out: GPT-5.5 costs $5.00/M input at the API and 125 credits in Codex, so 1 credit equals 4 cents. The same ratio holds for every row (GPT-5.4: $2.50/M and 62.5 credits; GPT-5.3-Codex: $1.75/M and 43.75 credits). Credits are API token pricing in different units.

Practical consequences:

• Switching from GPT-5.5 to GPT-5.4 in Codex halves your burn rate for the same token volume. GPT-5.3-Codex burns about a third of GPT-5.5 on input.
• Output is 6x the input rate on every model. Tasks that generate a lot of code (test generation, scaffolding) burn credits much faster than tasks that mostly read (debugging, code review).
• Cached input is 10x cheaper than fresh input. Long sessions in one repo benefit; jumping between repos resets the cache advantage.

What a Codex Session Actually Costs

A typical coding session costs $0.50-$2.00 at API rates. Using the burn table above, you can derive per-task costs on GPT-5.5 from token volume:

Token volumes are estimates; the credit arithmetic is exact (input tokens x 125 + output tokens x 750, per million, at 4 cents per credit). The published 5-45 credits-per-message average brackets the same range: $0.20-$1.80 per message. Output-heavy work like test generation costs disproportionately more because output burns 750 credits/M versus 125 for input.

This also explains why two developers on the same plan report wildly different experiences. One running small fixes gets 80 messages per window. One running 300k-token agentic refactors gets 15.

Codex API Pricing

Running Codex with an API key (or calling the models directly) bills per token with no subscription. Current OpenAI API rates:

gpt-5.3-codex replaced gpt-5.2-codex (released January 14, 2026) at identical pricing. For calibration, gpt-5.2-codex scores 41.04% on SWE-bench Pro public and 27.74% on the private set under Scale's standardized scaffolding. Regional data-residency endpoints carry a 10% price uplift. gpt-5.5 and gpt-5.4 both run 1M-token context with 128K max output; gpt-5.4-mini is 400K context.

Codex CLI Pricing

Codex CLI itself is free software. You pay through one of two channels:

• ChatGPT sign-in: included on every plan, even Free ($0/mo) and Go ($8/mo). CLI usage draws from the same 5-hour-window limits as Codex web and IDE, so a heavy CLI session and a heavy web session compete for the same allowance.
• API key: per-token billing at the rates above. No window limits, no cloud features. Costs scale linearly with usage.

The CLI also supports custom model providers via config.toml (base_url, env_key, wire_api), so you can point it at any Responses-compatible endpoint. Setup details in our Codex provider configuration guide.

Business and Enterprise: Pay-As-You-Go Seats

Business pricing is pay-as-you-go: instead of a fixed per-seat subscription with window limits, seats bill for the tokens they actually consume. For teams with uneven usage (three heavy agent users, ten occasional ones), this beats paying $100-200 per seat for capacity most seats never touch.

What Business and Enterprise add over individual plans: cloud features, GitHub, Slack, and Linear integrations, and admin controls. Enterprise and Edu are custom contracts on top of the same model.

Is Codex Free? What Remains After the Promo

Yes, with caveats. Codex is included in ChatGPT Free at $0/month, including CLI access via ChatGPT sign-in. What changed: the promotional period that boosted free-tier limits has ended, so Free now carries the lowest limits of any plan. There is no separate student price for Codex; students use the same Free, Go, or Plus plans (Enterprise/Edu covers institutions).

If Free limits block you, the upgrade ladder is Go at $8/month, then Plus at $20/month. Plus is the first tier with credit top-ups when you hit a window limit.

Codex vs Claude Code Pricing

The two ladders now mirror each other almost exactly:

At matching sticker prices, the decision moves to capability per dollar. Claude Opus 4.8 scores 88.6% on SWE-bench Verified at $5/M input and $25/M output. On Scale's standardized SWE-bench Pro leaderboard, gpt-5.2-codex scores 41.04% public / 27.74% private versus claude-opus-4-6 at 51.9% / 47.1%. One pricing nuance in Codex's favor: gpt-5.3-codex input is $1.75/M versus $3-5/M for Claude's coding models, which matters for read-heavy agentic work. Full breakdowns in Claude Code pricing and Codex vs Claude Code.

When the API Beats a Subscription

At $0.50-$2.00 per session, an API key beats Plus ($20/mo) below 10-40 sessions per month, and beats Pro 5x ($100/mo) below 50-200 sessions. Short sessions push the breakeven up; long agentic sessions pull it down.

The API route fits developers who batch work into occasional deep sessions, teams building products on top of the models, and anyone who wants gpt-5.4-mini at $0.75/$4.50 per million tokens for high-volume simple tasks. What you give up: cloud features, GitHub/Slack/Linear integrations, and the predictable flat monthly bill. Daily users come out ahead on a subscription because window allowances cover far more tokens than the same dollars buy at API rates.

Which Plan Should You Pick

Free or Go ($0-8/mo)

You want to evaluate Codex CLI or use it a few times a week. Free works for evaluation; Go at $8/month is the cheapest plan with usable headroom.

Plus ($20/mo)

You code regularly but not in all-day agentic sprints. 15-80 GPT-5.5 messages per 5-hour window covers most individual workflows, and credit top-ups handle the occasional overage without a plan change.

Pro 5x ($100/mo)

You hit Plus limits weekly. 75-400 GPT-5.5 messages per window, plus the Codex-Spark research preview. This is the tier for daily multi-file agentic work.

Pro 20x ($200/mo)

You run parallel agents or sustained refactors. 300-1,600 messages per window. Twice the price of Pro 5x for four times the capacity, so heavy users get better unit economics here.

Business / Enterprise

Your team needs integrations and admin controls, or has uneven usage where pay-as-you-go seats beat fixed subscriptions. Enterprise adds custom contracts.

API key

Under 10-40 sessions per month, or you need programmatic access. gpt-5.3-codex at $1.75/$14 per million tokens, no window limits.

Pricing History

Frequently Asked Questions