Codex credits: what they cost and when to buy them

How much do Codex credits cost?

OpenAI doesn't print a dollar price per credit in its docs. The credits help article says purchase amounts and prices "can vary by account, region, and plan", so the number to trust is the one on your checkout screen.

What OpenAI does publish is how many credits each model burns per million tokens, and those rates line up exactly with its API prices: every one is 25x the dollar price. GPT-6.1 Sol costs $2 per 1M input tokens on the API and 50 credits in Codex. Voice in the desktop app is listed both ways too: $0.05 a minute of usage budget, or 1.25 credits a minute. Both point to one credit being worth about $0.04 of API usage (our estimate).

In practice: OpenAI says a typical GPT-6.1 Sol task uses 2 to 15 credits. At about $0.04 a credit that's $0.08 to $0.60 a task (our estimate). GPT-6 Astra costs 5x GPT-6.1 Sol per input token, and GPT-6 Luna costs a twentieth of it, so switching models moves your bill far more than anything else.

GPT-5.6 Sol is on a promotional rate for purchased credits at least through Nov 21, 2026, per OpenAI's rate card. Codex credit billing has no separate cache-write charge.

Fast and Ultrafast modes cost more credits

Speed modes multiply the Standard rate. Per OpenAI's pricing page:

So a task that costs 10 credits at Standard speed costs 20 on Fast and 60 on Ultrafast. Ultrafast is only on Pro 500 and eligible Enterprise and Edu plans. If you're paying by the credit, Standard speed is the cheap setting.

How to buy Codex credits

1. Hit your Codex limit on Plus or Pro and pick the option to add credits, or go there directly.
2. Open Settings > Usage in ChatGPT, or Usage & Billing in the Codex app. Your Codex usage dashboard shows your balance.
3. Buy a one-time amount. Checkout may apply ChatGPT wallet funds on the website, but only if it shows them applied.
4. Optional: turn on automatic reload. You pick a minimum balance, a target balance and a maximum monthly spend.

Two catches from OpenAI's help article. Your ChatGPT wallet (including gift card money) is a separate balance, and redeeming a gift card doesn't add credits. And if a task finishes after your balance hits zero, the balance can go negative; your next purchase pays that off first.

Codex credits vs upgrading to Pro

Pro 100 costs $80 a month more than Plus ($20). At about $0.04 a credit, $80 buys roughly 2,000 credits, or 133 to 1,000 typical GPT-6.1 Sol tasks (our estimate). Pro 100 also currently has no five-hour limit, per OpenAI's Codex pricing page.

For scale, independent tracker wokey.ai puts a week of ChatGPT Plus Codex usage at about $58 of API-rate value (about 1,450 credits at our rate; measured on 8 accounts as of Oct 19, 2026, so treat it as rough). If you're buying more than one extra Plus-week of credits a month, you're paying Pro money without getting Pro.

• Buy credits if you run out once or twice a month, or need to finish one job before the reset.
• Move to Pro 100 if your top-ups would pass about $80 a month, or the five-hour limit is what keeps stopping you.
• Wait for the reset if the work can wait. On Plus, limits refill every 5 hours and weekly; our Codex reset tracker also logs the free resets OpenAI staff announce.

Another option for local work: sign Codex in with an API key and pay API rates directly. You lose cloud features like GitHub code review and Slack, per OpenAI.

Codex credit rules worth knowing

• Shared pool: one balance covers Codex, ChatGPT Work, Word, Excel and PowerPoint, so credits bought in Codex can pay for an Excel task.
• Expiry: credits last 12 months from purchase and don't roll over after that.
• Refunds: none, unless it's a verified billing error, unauthorized use, or a confirmed OpenAI service failure or wrong account restriction.
• Not API credits: they don't work on the OpenAI API platform, and they can't be transferred, gifted or resold.
• Free safety checks: auto-review checks ("Approve for me") are free when you're signed in with ChatGPT and don't touch your limit or credits.

If your Codex usage is vanishing faster than these numbers suggest, check our Codex usage draining fast guide before you buy anything.