GPT-5.1-Codex-Max

Name: GPT-5.1-Codex-Max
Author: OpenAI

reasoningdeprecatedproprietary

Status: Shut down · Succeeded by gpt-5.6-sol

Intelligence

Reasoning

Speed

Context

400K

Max output

128K

Input price

$1.25/1M tokens

Output price

$10/1M tokens

Capabilities

Show unsupported (3)

Reasoning & Interaction

Reasoning

Tool Calling

Output Control

Structured Output

JSON Mode

Infrastructure

Streaming

Details

ProviderOpenAI

Creatoropenai

Familygpt-5.1

Licenseproprietary

Statusdeprecated

Typereasoning

Input modalitiestext, image

Output modalitiestext

Open weightNo

Parameters—

Architecture—

Context window400K tokens

Max input—

Max output128K tokens

Reasoning tokensYes

Knowledge cutoff2024-09

Release date—

Deprecation date2026-04-22

Retirement date2026-07-23

Successorgpt-5.6-sol

Sourceofficial

Tools

Function Callingfunction_calling

Call external functions and APIs

Web Searchweb_search

Search the web for information

Endpoints

ResponsesPOST

Stateful multi-turn conversationshttps://api.openai.com/v1/responses

Pricing

Text tokensPer 1M tokens

	Input	Cached input	Output
Standard	$1.25	$0.125	$10

Family Comparison: gpt-5.1

Model	Caps	Perf	Speed	Context	Max out	Pricing
GPT-5.1-Codex Mini	RTJJMS			400K	128K	$0.25$2
GPT-5.1 Chat	TJJMS			128K	16K	$1.25$10
GPT-5.1-Codex-Max	RTJJMS			400K	128K	$1.25$10
GPT-5.1-Codex	RTJJMS			400K	128K	$1.25$10
gpt-5.1-latest	S	—	—	—	—	$1.25$10
GPT-5.1	RTJJMSB			400K	128K	$1.25$10

API

GET/v1/models/openai/gpt-5.1-codex-max

GPT-5.1-Codex-Max

deprecated

Status: Shut down

gpt-5.1-codex-max

Changes · 10 entries

gpt-5.1-codex-maxupdateca7a400Nov 2, 2026, 03:02 AM

descriptionGPT‑5.1-Codex-Max is purpose-built for agentic coding.→Status: Shut down

deprecation_date2026-04-22

retirement_date2026-07-23

successorgpt-5.6-sol

gpt-5.1-codex-maxupdateb2f45bfOct 29, 2026, 03:29 AM

descriptionGPT‑5.1-Codex-Max is purpose-built for agentic coding. It...→Status: Shut down

gpt-5.1-codex-maxupdate118451aSep 24, 2026, 07:08 AM

descriptionGPT‑5.1-Codex-Max is purpose-built for agentic coding.→GPT‑5.1-Codex-Max is purpose-built for agentic coding. It...

deprecation_date2026-04-22

retirement_date2026-07-23

successorgpt-5.6-sol

gpt-5.1-codex-maxupdate6a1e7e3Apr 24, 2026, 02:41 AM

statusactive→deprecated

gpt-5.1-codex-maxupdatefa2bbbbMar 24, 2026, 05:22 AM

capabilitiesjson modeno→yes

gpt-5.1-codex-maxupdatef43e286Mar 24, 2026, 04:45 AM

capabilitiesjson modeyes→nofine tuningno

gpt-5.1-codex-maxupdate1cd659eMar 24, 2026, 04:19 AM

capabilitiesjson modeyes

page_urlhttps://platform.openai.com/docs/models/gpt-5.1-codex-max→https://developers.openai.com/api/docs/models/gpt-5.1-cod...

gpt-5.1-codex-maxupdate2b100acMar 23, 2026, 05:30 AM

licenseproprietary

page_urlhttps://platform.openai.com/docs/models/gpt-5.1-codex-max

open_weightno

gpt-5.1-codex-maxupdateb50649fMar 21, 2026, 11:58 PM

pricingtiers[{"label":"Text tokens","unit":"Per 1M tokens","columns":...

knowledge_cutoff2024-09

reasoning_tokensyes

reasoning4

taglineA version of GPT-5.1-codex optimized for long running tasks.

tools["function_calling","web_search"]

endpoints["responses"]

snapshots["gpt-5.1-codex-max"]

gpt-5.1-codex-maxcreate7f5c66fMar 21, 2026, 05:16 AM