OpenCode and Codex cost the same for OpenAI models in almost every setup. OpenCode can sign in with your ChatGPT Plus or Pro plan, so it draws on the same allowance that pays for Codex, and its Zen gateway sells GPT-5.6 at OpenAI's list rate of $4 in and $20 out per million tokens. The real differences are three: Codex bundles cloud tasks and GitHub code review into the plan, OpenCode can switch to non-OpenAI models, and OpenCode's $10 Go plan undercuts ChatGPT Plus if an open model is good enough for your work.
Most comparisons frame this as a free open-source tool against a paid OpenAI product. That describes the software, not the bill. We read OpenAI's Codex pricing documentation and OpenCode's provider, Zen and Go docs to work out what a developer or a team actually pays in each.
How much does Codex cost?
Codex has no price of its own. It comes with a ChatGPT plan, and the plan sets how many messages you can send in each five-hour window. OpenAI publishes those windows as ranges because a long agent turn uses more of the allowance than a short one.
| ChatGPT plan | Price | GPT-5.6 Sol messages per 5 hours | What else it includes |
|---|---|---|---|
| Go | $8/mo | Lightweight tasks only | A reduced Codex, not the full product |
| Plus | $20/mo | 10 to 100 | CLI, IDE extension, web, cloud tasks, GitHub code review, Slack, extra credits |
| Pro 5x | $100/mo | 50 to 500 | Same product, five times the allowance |
| Pro 20x | $200/mo | 200 to 2,000 | Twenty times Plus for ten times the price |
| Business | $20/user annual, $25 monthly | Same as Plus | SSO, admin controls, no training on business data by default; a $100 seat uses the Pro 5x figures |
Past the window you can buy extra credits and keep going. OpenAI's credit rate card works out to its API price list at 25 credits per dollar, which we traced line by line in Cline vs Codex. You can also sign Codex in with an API key and pay token rates directly, but that route has no cloud-based features.
How much does OpenCode cost?
The OpenCode software is free and MIT-licensed. You pay for the model, and with OpenAI models there are four ways to do it:
- Your ChatGPT plan. OpenCode's OpenAI provider has a ChatGPT Plus/Pro sign-in that opens your browser to authenticate. OpenCode's docs actually recommend a ChatGPT plan for OpenAI models.
- An OpenAI API key. OpenAI bills you directly at list rates and OpenCode takes nothing.
- OpenCode Zen. A pay-as-you-go gateway with a curated model list, sold at list rate, with card fees of 4.4% plus $0.30 passed through on each top-up.
- OpenCode Go. $10 a month for 27 mostly open models, including GPT 5.6 Luna but not Sol or GPT-6 Astra.
Can I use OpenCode with ChatGPT subscription?
Yes. OpenCode lists ChatGPT Plus alongside GitHub Copilot and GitLab Duo as subscriptions that work "with zero setup", and it contrasts that with Anthropic, which prohibits using Claude plans in third-party tools. So the first answer to "OpenCode or Codex" for anyone already paying OpenAI is that the harness costs nothing extra either way. The same plan pays for both, and usage in OpenCode comes out of the same allowance as Codex.
That changes what you are choosing between. On a ChatGPT plan, OpenCode and Codex are two front ends on one meter. The question stops being price and becomes which harness does the work you need, plus which extras you lose if you leave Codex.
OpenCode Zen vs Codex credits: is either cheaper per token?
No. We compared Zen's published rates against OpenAI's API price list and they match to the cent for every GPT model Zen carries:
| Model | OpenCode Zen, per million tokens | OpenAI API, per million tokens | Codex credits, per million tokens |
|---|---|---|---|
| GPT-6 Astra | $10.00 in, $50.00 out | $10.00 in, $50.00 out | 250 in, 1,250 out |
| GPT-5.6 Sol | $4.00 in, $20.00 out | $4.00 in, $20.00 out | 100 in, 500 out |
| GPT-5.6 Terra | $2.00 in, $12.00 out | $2.00 in, $12.00 out | 50 in, 300 out |
| GPT-5.6 Luna | $0.20 in, $1.20 out | $0.20 in, $1.20 out | 5 in, 30 out |
At 25 credits to the dollar, the Codex column is the same price again. So metered GPT costs the same whether it runs through OpenCode on Zen, OpenCode on your own key, or Codex past its plan cap. Zen adds only the card fee: on its default $20 auto-reload that is $1.18, just under 6%. For someone who codes most weeks, a ChatGPT plan beats all three meters, because OpenAI puts GPT-5.6 at 5 to 30 credits per message, which means $20 of metered usage buys roughly 17 to 100 messages while Plus includes up to 100 Sol messages in every five-hour window.
Is OpenCode Go cheaper than ChatGPT Plus for coding?
On the invoice, yes: $10 against $20. On what the money buys, it depends on the model you need. Go gives each model a monthly allowance in dollars, capped at 20% per five hours and 50% per week. GPT 5.6 Luna gets $15 of usage a month, which OpenCode estimates at about 2,050 requests per five hours, and MiniMax M3 or Qwen3.7 Plus get $60. What Go does not include is GPT-5.6 Sol or GPT-6 Astra, the models Codex users reach for on hard tasks.
So Go is cheaper for a developer whose work is mostly routine edits that a small or open model handles well. It is not a Plus replacement for someone who needs Sol most of the day. OpenCode also says Go is "designed primarily for international users", and only one member per workspace can subscribe, which makes it a personal plan rather than a team purchase.
What you give up by leaving Codex
Codex on a ChatGPT plan is more than a terminal agent. Plus and above include cloud tasks that run in OpenAI's environment against a connected repository, automatic code review on GitHub pull requests, and a Slack integration. OpenCode on the same plan gives you the local agent only. If your team leans on those extras, the harness choice has a real cost even though the token price does not. We break down the local side in more detail on our Codex CLI pricing page.
What you gain in OpenCode is model freedom. The same session can use GPT on your ChatGPT plan, a Copilot model on your company's Copilot seat, or an open model on Go, and OpenCode reads your existing AGENTS.md file. Codex runs OpenAI models only.
OpenCode vs Codex: which should you pay for?
| Your situation | Pay for | Why |
|---|---|---|
| You already pay for ChatGPT Plus or Pro and use cloud tasks or PR review | Codex | The extras come with the plan and OpenCode cannot replace them |
| You already pay for ChatGPT and only use the local agent | Either, same plan | OpenCode on the ChatGPT sign-in costs nothing more; pick the harness you prefer |
| You want GPT plus other vendors in one tool | OpenCode | ChatGPT, Copilot and GitLab Duo logins plus 75+ API providers |
| You want the smallest possible bill for routine work | OpenCode Go, $10 | Open models and GPT 5.6 Luna, capped per model |
| You use GPT a few days a month | Either, on metered tokens | Zen, an API key and Codex credits all price GPT the same |
Codex vs OpenCode for a team
For a team, Codex means ChatGPT Business at $20 a user a month billed annually, or $25 monthly, with a $100 seat on Pro 5x limits for the one or two developers who keep hitting the cap. OpenCode offers two shapes. OpenCode Enterprise is priced per seat on a custom quote, with a central config, SSO and a lock to your internal AI gateway, and OpenCode says it does not charge for tokens when you bring your own gateway. Zen team workspaces, free while in beta, add admin and member roles and a monthly spending limit per member.
The Zen route has a finance side worth planning for. Auto-reload charges the card $20 each time the balance drops under $5, so a busy team produces a stream of small card charges instead of one invoice, each with its own $0.30 fee. Someone has to reconcile those card charges against the statement every month, which is a cost ChatGPT Business, billed per seat, does not create.
If you are weighing the same question on the Anthropic side, the answer flips: Claude plans cannot be used inside OpenCode, so Claude there is always metered. We priced that in OpenCode vs Claude Code.
When neither is the right purchase
OpenCode and Codex are both agents you drive from the keyboard, and both put your work on a quota or a meter you have to watch. If what your team wants is to describe a task and get back a tested pull request, Agentcode does that on a GitHub or GitLab repository for $29 a month billed yearly, with no key, no credit balance and no five-hour window. It never merges on its own; a person reviews every change. For how the terminal agents compare with each other on price, see Cursor CLI vs Codex CLI.
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