GPT-5.1-Codex

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

Reasoning & Interaction
Reasoning
Tool Calling
Output Control
Structured Output
JSON Mode
Infrastructure
Streaming

Details

Provider OpenAI
Creator openai
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 cutoff
Release date—
Deprecation date
Retirement date
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
InputCached inputOutput
Standard$1.25$0.125$10

Family Comparison: gpt-5.1

ModelContextMax outPricing
GPT-5.1-Codex Mini400K128K$0.25$2
GPT-5.1 Chat128K16K$1.25$10
GPT-5.1-Codex-Max400K128K$1.25$10
GPT-5.1-Codex400K128K$1.25$10
gpt-5.1-latest——$1.25$10
GPT-5.1400K128K$1.25$10

API

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

GPT-5.1-Codex

deprecated

Status: Shut down

gpt-5.1-codex
Changes · 11 entries
gpt-5.1-codexupdateca7a400Nov 2, 2026, 03:02 AM
nameGPT-5.1 Codex→GPT-5.1-Codex
descriptionGPT-5.1-Codex is a version of GPT-5 optimized for agentic...→Status: Shut down
deprecation_date2026-04-22
retirement_date2026-07-23
successorgpt-5.6-sol
gpt-5.1-codexupdateb2f45bfOct 29, 2026, 03:29 AM
descriptionGPT-5.1-Codex is a version of GPT-5 optimized for agentic...→Status: Shut down
gpt-5.1-codexupdate118451aSep 24, 2026, 07:08 AM
descriptionGPT-5.1-Codex is a version of GPT-5 optimized for agentic...→GPT-5.1-Codex is a version of GPT-5 optimized for agentic...
deprecation_date2026-04-22
retirement_date2026-07-23
successorgpt-5.6-sol
gpt-5.1-codexupdated68a4f1Jun 10, 2026, 02:10 AM
nameGPT-5.1 Codex→GPT-5.1-Codex
gpt-5.1-codexupdate6a1e7e3Apr 24, 2026, 02:41 AM
statusactive→deprecated
gpt-5.1-codexupdatefa2bbbbMar 24, 2026, 05:22 AM
capabilitiesjson modeno→yes
gpt-5.1-codexupdatef43e286Mar 24, 2026, 04:45 AM
capabilitiesjson modeyes→nofine tuningno
gpt-5.1-codexupdate1cd659eMar 24, 2026, 04:19 AM
capabilitiesjson modeyes
page_urlhttps://platform.openai.com/docs/models/gpt-5.1-codex→https://developers.openai.com/api/docs/models/gpt-5.1-codex
gpt-5.1-codexupdate2b100acMar 23, 2026, 05:30 AM
licenseproprietary
page_urlhttps://platform.openai.com/docs/models/gpt-5.1-codex
open_weightno
gpt-5.1-codexupdateb50649fMar 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 optimized for agentic coding in Codex.
tools["function_calling","web_search"]
endpoints["responses"]
snapshots["gpt-5.1-codex"]
gpt-5.1-codexcreate7f5c66fMar 21, 2026, 05:16 AM