GPT-5.1 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 2027-04-01 · suggested replacement: GPT-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; 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 has held the same list price since 2026-08-15 and is the 85th cheapest of 113 models in the Mid-range price tier. None of its 2 hosts undercuts the price we quote. 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): $0.625 / $5.00 per 1M tokens
- Prompt-cache read: $0.125 per 1M tokens
- Context window: 400K tokens
- Arena ELO: 1422 as of 2026-11-08
Available on
Direct API, Azure AI Foundry, OpenRouter
Curated by hand; check with the provider before committing.
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. Its Arena ELO of 1422 ranks 75th of the 160 models that carry one, tied with one other, above 53% of them.
Licence, size and capabilities
GPT-5.1 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 2 different hosts. 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.
The price we quote is already the cheapest of the 2 hosts: OpenAI at $1.25 input / $10.00 output per 1M tokens. All of them charge within 10% of one another.
| Host | Input $/1M | Output $/1M |
|---|---|---|
| OpenAI (model maker, price we quote) | $1.25 | $10.00 |
| 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 | $586 – $688 |
| Knowledge Q&A | 2,000 / 800 | $893 – $1.1K |
| Meeting Summary | 10,000 / 1,200 | $1.2K – $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 | $371 – $788 |
| Call Summary | 2,000 / 700 | $465 – $950 |
| Agent Workflow | 6,000 / 3,000 | $3.3K – $3.8K |
Price history
GPT-5.1 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
4 of the 4 comparable models below cost less than GPT-5.1: Mistral Medium 3.1 undercuts it by 79%, and scores 3 Arena points higher.
- 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.
The nearest models in the Mid-range price tier on Arena ELO, each with its blended price and score difference against GPT-5.1.
- Mistral Medium 3.5 (Mistral): $1.50 in / $7.50 out per 1M, Arena ELO 1421 (23% cheaper, 1 ELO point lower)
- Mistral Medium 3.1 (Mistral): $0.40 in / $2.00 out per 1M, Arena ELO 1425 (79% cheaper, 3 ELO points higher)
- Qwen3.5-122B-A10B (Alibaba): $0.26 in / $2.08 out per 1M, Arena ELO 1417 (79% cheaper, 5 ELO points lower)
- Gemini 2.5 Flash (Google): $0.30 in / $2.50 out per 1M, Arena ELO 1417 (75% cheaper, 5 ELO points lower)
- Cheapest within 15 Arena points: Gemma 4 26B A4B (Google), 99% cheaper, 12 ELO points higher, out of 35 models in that band.
- Highest Arena ELO within 20% of this price: Gemini 4 Argon (Google), 3% more expensive, 108 ELO points higher, out of 14 models in that price band.
Other models from OpenAI
The 8 nearest to GPT-5.1 in price, of 48 other OpenAI models in the catalogue. Prices per 1M tokens, input then output.
- GPT-6.1 Terra Pro: $1.00 / $5.00
- GPT-4.1: $2.00 / $8.00
- o3: $2.00 / $8.00
- GPT-5: $1.25 / $10.00
- GPT-5.1-Codex: $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
All 49 OpenAI models and prices
Common questions about GPT-5.1 pricing
- How much does GPT-5.1 cost?
- GPT-5.1 costs $1.25 per 1M input tokens and $10.00 per 1M output tokens. That is the model maker's own rate (OpenAI). Prices as listed on 2026-11-12.
- Which host is cheapest for GPT-5.1?
- The price we quote is already the cheapest of the 2 hosts: OpenAI at $1.25 input / $10.00 output per 1M tokens. All of them charge within 10% of one another. Host rates as listed on 2026-11-12.
- Does GPT-5.1 offer batch or cached pricing?
- Yes, both. Batch API pricing is $0.625 per 1M input tokens and $5.00 per 1M output tokens, and prompt-cache reads cost $0.125 per 1M tokens, as listed on 2026-11-12.
- What would GPT-5.1 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 at the list price quoted on 2026-11-12.
- Can GPT-5.1 be self-hosted?
- No, as far as this site records. GPT-5.1 is recorded here as proprietary: access is through an API, priced by the token.
- Has the price of GPT-5.1 changed?
- GPT-5.1 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 batch rate, and that discount is conditional: when the batch discount applies.
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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