GPT-5.1 Codex Max pricing & specs

OpenAI · released 2025-11-13 · ● verified 2026-10-11

input / 1M$1.25via Azure
output / 1M$10.00via Azure
context400K
max output128K

// price history ($/1M tokens)

$11.50
input $/1Moutput $/1M2025-11-13 → 2026-10-11

// cheaper or similar alternatives

modelinoutctxvs GPT-5.1 Codex Max
Qwen3.7 Flash$0.03$0.131M−98.4%
Qwen3.5 9B$0.10$0.15262.1K−96.7%
Gemma 4 26B A4B IT$0.07$0.34262.1K−96%
GPT-5 Nano$0.05$0.40400K−96%
Qwen3.5 Flash$0.10$0.401M−94.9%
Claude Sonnet 5 vs GPT-5.1 Codex Max →Claude Sonnet 5.5 vs GPT-5.1 Codex Max →Gemini 3.1 Pro Preview vs GPT-5.1 Codex Max →Gemini 3.1 Pro Preview Custom Tools vs GPT-5.1 Codex Max →GPT-5.1 Codex Max vs Grok 4.6 →GPT-5.1 Codex Max vs Grok 4.7 →

// price by host

hostin $/1Mout $/1M
Azure$1.25$10.00

// faq

How much does GPT-5.1 Codex Max cost?

GPT-5.1 Codex Max costs $1.25 per million input tokens and $10.00 per million output tokens (cheapest tracked host: Azure). At 50M input and 10M output tokens per month that is about $163.

What is the context window of GPT-5.1 Codex Max?

400K tokens, with up to 128K output tokens per request.

Does GPT-5.1 Codex Max support prompt caching?

Yes. Cached input tokens cost $0.125 per million.

What are cheaper alternatives to GPT-5.1 Codex Max?

Qwen3.7 Flash ($0.03 in / $0.13 out), Qwen3.5 9B ($0.10 in / $0.15 out), Gemma 4 26B A4B IT ($0.07 in / $0.34 out) offer the same input types and capabilities for less.

// spec sheet

input / 1M
$1.25
output / 1M
$10.00
cache read / 1M
$0.125
blended (3:1)
$3.4375
context
400K
max output
128K
input types
text · image
reasoning
yes
tool calling
yes
structured output
yes
open weights
no
knowledge cutoff
2024-09-30
price source
Azure

report a data error

// cost calculator

modelin $/1Mout $/1M= monthly
Qwen3.7 Flash$0.03$0.13$2.80
Qwen3.5 9B$0.10$0.15$6.50
Gemma 4 26B A4B IT$0.07$0.34$6.90
GPT-5.1 Codex Max$1.25$10.00$163

Base-tier list prices. Long-context tiers, caching and batch discounts are not included.