GPT-5.1 vs GPT-5.1-Codex-Max
Pick up to 3 models · pricing, context and capabilities · simulate your product cost
Data updated on September 30, 2026· 217 models
GPT-5.1 is the latest frontier-grade model in the GPT-5 series, offering stronger general-purpose reasoning, improved instruction adherence, and a more natural conversational style compared to GPT-5.
- Reasoning estimated
- Speed estimated
- Input
- Output
- Context
- 400 K tokens
- Max output
- 128 K
- Input, $ per 1M tokens
- $1.25
- Output, $ per 1M tokens
- $10.00
- Cache read, $ per 1M
- $0.125
- Batch (input / output)
- $0.625 / $5.00
- Tool calling
- Yes
- Released
- 11/13/2025
- Knowledge cutoff
- 2024-09-30
- API id
- openai/gpt-5.1
GPT-5.1-Codex-Max is OpenAI’s latest agentic coding model, designed for long-running, high-context software development tasks.
- Reasoning estimated
- Speed estimated
- Input
- Output
- Context
- 400 K tokens
- Max output
- 128 K
- Input, $ per 1M tokens
- $1.25
- Output, $ per 1M tokens
- $10.00
- Cache read, $ per 1M
- $0.125
- Batch (input / output)
- —
- Tool calling
- Yes
- Released
- 11/13/2025
- Knowledge cutoff
- 2024-09-30
- API id
- openai/gpt-5.1-codex-max
Which is the better API choice: GPT-5.1 vs GPT-5.1-Codex-Max?
GPT-5.1 and GPT-5.1-Codex-Max cost the same ($1.25 input, $10.00 output per million tokens). All accept 400 K tokens of context. GPT-5.1 offers a batch tier at half price for jobs that do not need an immediate answer.
What would your product cost?
Estimate the monthly cost with your app's real volume. List prices, no cache or batch discounts.
They cost the same at this volume.
The 6 cheapest for this scenario (chat, last 12 months)
- 1Lyria 3 Pro Preview Google$0.00
- 2Lyria 3 Clip Preview Google$0.00
- 3Qwen3.7 Flash Qwen$0.97
- 4DeepSeek V4 Flash 0731 DeepSeek$1.55
- 5Ministral 3 3B 2512 Mistral$1.90
- 6Qwen3.5-Flash Qwen$2.02
Paste your prompt: tokens and cost per model
Rough estimate (about 4 characters per token). Nothing is sent to any server.
Cost of sending it 1,000 times (input only)
- 1GPT-5.1 OpenAI$0.095
- 2GPT-5.1-Codex-Max OpenAI$0.095
- 3Claude Sonnet 5.5 Anthropic$0.152
- 4Claude Sonnet 5 Anthropic$0.152
- 5Claude Opus 5.5 Anthropic$0.304
- 6Claude Opus 5 Anthropic$0.380
- 7Claude Fable 5.1 Anthropic$0.760
- 8Claude Fable 5 Anthropic$0.760
Popular comparisons
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- Gemini 3.8 Flash vs DeepSeek V4.1 Flash
- Gemini 3.8 Flash vs Grok 4.7
- DeepSeek V4.1 Flash vs Grok 4.7
Frequently asked questions
Which is the better API choice: GPT-5.1 vs GPT-5.1-Codex-Max?
GPT-5.1 and GPT-5.1-Codex-Max cost the same ($1.25 input, $10.00 output per million tokens). All accept 400 K tokens of context. GPT-5.1 offers a batch tier at half price for jobs that do not need an immediate answer.
Which is cheaper: GPT-5.1 and GPT-5.1-Codex-Max?
GPT-5.1 and GPT-5.1-Codex-Max cost the same: $1.25 per million input tokens and $10.00 output.
Which has more context: GPT-5.1 and GPT-5.1-Codex-Max?
GPT-5.1 and GPT-5.1-Codex-Max accept the same context: 400 K tokens.
What would 10,000 requests a month cost with GPT-5.1 and GPT-5.1-Codex-Max?
With 1,500 input and 400 output tokens per request: GPT-5.1: $58.75; GPT-5.1-Codex-Max: $58.75 a month, at list price.
Where do the prices come from and how often are they updated?
From the public catalogs of OpenRouter, models.dev and LiteLLM, which publish each provider's list prices. They sync once a day and the last update date is shown above the comparison.
What does price per million tokens mean?
It is what the provider charges per million tokens you send (input) or the model generates (output). A token is roughly 4 characters. Output almost always costs more than input.
Sources: OpenRouter, models.dev and LiteLLM. Prices in USD per million tokens, list price, no volume discounts. Prompt tokens are an estimate; each provider's tokenizer may differ.