One agent session
1M input tokens and 100K output tokens, no caching.
- Input1M x $1.75 = $1.75
- Output0.1M x $14 = $1.40
$3.15per session
OpenAI - Closed weights
GPT-5.3-Codex pricing and specs
GPT-5.3-Codex is a closed-weights model from OpenAI that costs $1.75 per 1M input tokens and $14 per 1M output tokens on the first-party API, with a 400K-token context window.
Last verified from developers.openai.com. All sources
- Input / 1M
- $1.75
- Output / 1M
- $14
- Context
- 400K tokens
- Weights
- Closed
Pricing per 1M tokens
| Item | Price / 1M tokens |
|---|---|
| Input | $1.75 |
| Output | $14 |
| Cache read | $0.175 |
| Fast mode inputFast mode requests | $3.50 |
| Fast mode outputFast mode requests | $28 |
Note: Listed under Specialized models (Codex) on the pricing page, which gives Standard and Fast prices only, so Batch is not stated. Released to the Responses API. Maximum input tokens 272,000.
Specs
- Context window
- 400,000 tokens
- Max output
- 128,000 tokens
- Release date
- Provider
- OpenAI
- API model id
gpt-5.3-codex- Vercel AI Gateway id
openai/gpt-5.3-codex- Weights
- Closed weights
What GPT-5.3-Codex costs in practice
Worked from the standard list rates above, with the math shown so you can swap in your own token counts.
A chat app
10,000 requests a day at 2K input and 500 output tokens each.
- Input20M x $1.75 = $35.00
- Output5M x $14 = $70.00
$105.00per day
$3,150.00 per 30-day month
The same session at a 90% cache hit
90% of the input is read from the prompt cache. The one-time cache write premium is not included.
- Cached input0.9M x $0.175 = $0.1575
- Uncached input0.1M x $1.75 = $0.175
- Output0.1M x $14 = $1.40
$1.73per session
Compare with
| Model | Input / 1M | Output / 1M |
|---|---|---|
| GPT-5.3-Codex (this page) | $1.75 | $14 |
| GPT-5.2OpenAI | $1.75 | $14 |
| Claude Sonnet 4.5Anthropic | $3 | $15 |
| Claude Sonnet 4.6Anthropic | $3 | $15 |
| GPT-5.4OpenAI | $2.50 | $15 |
| GPT-5.6 TerraOpenAI | $2 | $12 |
| GPT-4oOpenAI | $2.50 | $10 |
| GPT-5OpenAI | $1.25 | $10 |
| GPT-5.1OpenAI | $1.25 | $10 |
Related reading
- Codex CLI 0.163: Instant Steering Is Now the DefaultCodex CLI 0.163.0 makes mid-response steering the default and adds searchable /config and a leader key. What changed and what to check before upgrading.
- Tool Calling Under the Hood: Claude Messages vs OpenAI ResponsesHow tool calling works on the wire: JSON schema tools, parallel calls, tool_choice, strict mode and streaming deltas in Claude Messages vs OpenAI Responses.
- Codex 'gpt-5.5 Model Is Not Supported' Error: The FixCodex says gpt-5.5 is not supported with a ChatGPT account because OpenAI retired it from ChatGPT sign-in on October 14. The fix and what still works.
- Codex CLI Background Daemon: How to Turn It OffCodex CLI starts a persistent, self-updating background daemon since 0.157.0. What it does, why it hit Hacker News and the reported workaround to turn it off.
- Codex CLI 0.162: Managed Worktrees and Pinned TasksCodex CLI 0.162 lets the agent create and list its own Git worktrees, adds pinned tasks and custom provider capability overrides. What to change this week.
- ChatGPT Free vs Go vs Plus After GPT-6: Which Model You GetFree and Go ($8) both get GPT-6 Luna in Chat. Plus ($20) is the cheapest plan with GPT-6 Sol and full Codex. What each ChatGPT plan buys now.
FAQ
How much does GPT-5.3-Codex cost per million tokens?
GPT-5.3-Codex costs $1.75 per 1M input tokens and $14 per 1M output tokens on OpenAI's first-party API, per developers.openai.com on October 17, 2026. Per 1M tokens, cache reads cost $0.175.
What is GPT-5.3-Codex's context window?
GPT-5.3-Codex has a 400,000-token context window and returns up to 128,000 output tokens per response.
Are GPT-5.3-Codex's weights open?
No. GPT-5.3-Codex is a closed-weights model. You call it through OpenAI's API as gpt-5.3-codex or through Vercel AI Gateway as openai/gpt-5.3-codex.
When was GPT-5.3-Codex released?
OpenAI released GPT-5.3-Codex on February 24, 2026.
Sources
Last verified from developers.openai.com.
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