GPT-5.1-Codex API pricing
OpenAI · Mid-range price tier · Proprietary · released 2025-11. Prices in USD per 1 million tokens. Data snapshot: 2026-11-12.
Deprecated. The model maker has announced retirement of this model's API · shutdown 2026-07-23 · suggested replacement: GPT-5.6 Sol. It still carries a price because hosts still serve it; treat it as a model to migrate off, not one to start on.
A support ticket workload of 100K requests a month costs $687.50 on GPT-5.1-Codex; the next cheaper model in the Mid-range price tier for this workload, Gemini 3.5 Flash, does it for $675.00. GPT-5.1-Codex has held the same list price since 2026-08-15 and is the 85th cheapest of 113 models in the Mid-range price tier. Only one host, Azure, sells it, so there is no second price to shop. Its maker has announced its retirement, so it is a model to migrate off rather than start on.
- Input: $1.25 per 1M tokens
- Output: $10.00 per 1M tokens
- Batch API (in/out): Not published
- Prompt-cache read: $0.13 per 1M tokens
- Context window: 400K tokens
- Arena ELO: Not published
Market position
On blended price ($7.375 per 1M tokens at 30% input, 70% output) it is cheaper than 21% of models in the Mid-range price tier: 85th cheapest of 113, tied with 5 others. Across every price tier it is cheaper than 18% of priced text models in the catalogue: 245th cheapest of 303, tied with 5 others.
Licence, size and capabilities
GPT-5.1-Codex is recorded here as proprietary: access is through an API, priced by the token. Its parameter count is not published. Listed capabilities: Text, Vision, Reasoning, Agents. Filling its 400K context window once costs $0.50 in input tokens at list price.
Pricing by host
A host is a company that runs the model and sells it by the token: the model maker, a cloud platform like Amazon Bedrock, Azure or Vertex, or an independent host. One model, several hosts, and often several prices. This model is sold by 1 host. The price we quote elsewhere on this page is marked. We quote one host's rate so that models stay comparable; it is not a recommendation to buy there.
Azure is the only host with a published rate, $1.25 input / $10.00 output per 1M tokens, which is the price we quote.
| Host | Input $/1M | Output $/1M |
|---|---|---|
| Azure (price we quote) | $1.25 | $10.00 |
List prices as published on 2026-11-12, via OpenRouter. Negotiated rates, committed-use discounts and provisioned capacity are not shown.
Monthly cost at 100K requests, by business use case
From the after-discounts figure (prompt caching on the cached input share, batch API for async workloads, only where OpenAI publishes those rates), which assumes you implement both, to the list price. One figure means no discount is published.
| Use case | Tokens (in/out) | Monthly (after discounts – list) |
|---|---|---|
| Support Ticket | 1,500 / 500 | $587 – $688 |
| Knowledge Q&A | 2,000 / 800 | $893 – $1.1K |
| Meeting Summary | 10,000 / 1,200 | $2.3K – $2.5K |
| Marketing Content | 2,500 / 1,800 | $2.1K |
| Coding Task | 3,000 / 2,000 | $2.2K – $2.4K |
| Invoice Processing | 1,500 / 600 | $737 – $788 |
| Call Summary | 2,000 / 700 | $928 – $950 |
| Agent Workflow | 6,000 / 3,000 | $3.3K – $3.8K |
Price history
GPT-5.1-Codex has been in our daily price archive since tracking began on 2026-08-15, when it listed at $1.25 input / $10.00 output per 1M tokens. No list price change since tracking began on 2026-08-15. Last checked against the 2026-11-12 snapshot.
Alternatives to GPT-5.1-Codex
GPT-5.1-Codex carries no Arena score, so this page cannot place it against models of comparable quality. The alternatives below are its nearest neighbours on price in the Mid-range price tier.
- Next cheaper model in the Mid-range price tier: GLM 5.3 Prime (Zhipu) at $7.00 blended, 5% less.
- Next more expensive: MiMo-V2.6-Pro-UltraSpeed (Xiaomi) at $7.395 blended, under 1% more.
Other models from OpenAI
The 8 nearest to GPT-5.1-Codex in price, of 48 other OpenAI models in the catalogue. Prices per 1M tokens, input then output.
- GPT-4.1: $2.00 / $8.00
- o3: $2.00 / $8.00
- GPT-5: $1.25 / $10.00
- GPT-5.1: $1.25 / $10.00
- GPT-5.1-Codex-Max: $1.25 / $10.00
- GPT-6 Sol: $2.00 / $10.00
- GPT-6 Sol Pro: $2.00 / $10.00
- GPT-6.1 Sol: $2.00 / $10.00
All 49 OpenAI models and prices
Common questions about GPT-5.1-Codex pricing
- How much does GPT-5.1-Codex cost?
- GPT-5.1-Codex costs $1.25 per 1M input tokens and $10.00 per 1M output tokens at Azure, the host whose rate we quote. Prices as listed on 2026-11-12.
- Which host is cheapest for GPT-5.1-Codex?
- Azure is the only host with a published rate, $1.25 input / $10.00 output per 1M tokens, which is the price we quote. Host rates as listed on 2026-11-12.
- Does GPT-5.1-Codex offer batch or cached pricing?
- Yes, for prompt caching only. Cache reads cost $0.13 per 1M tokens, as listed on 2026-11-12. No batch pricing is published.
- What would GPT-5.1-Codex cost per month?
- With the Support Ticket profile (1,500 input and 500 output tokens per request), 100,000 requests a month cost about $688 on GPT-5.1-Codex at the list price quoted on 2026-11-12.
- Can GPT-5.1-Codex be self-hosted?
- No, as far as this site records. GPT-5.1-Codex is recorded here as proprietary: access is through an API, priced by the token.
- Has the price of GPT-5.1-Codex changed?
- GPT-5.1-Codex has been in our daily price archive since tracking began on 2026-08-15, when it listed at $1.25 input / $10.00 output per 1M tokens. No list price change since tracking began on 2026-08-15. Last checked against the 2026-11-12 snapshot.
It publishes a prompt-cache rate, which is the discount most often left out of a budget: what prompt caching saves.
These are list prices. Your real cost also depends on caching and batching, negotiated discounts, marketplace agreements, and the contracts you already have. OptimNow audits exactly that.
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