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ModelRetiredClosed / proprietaryIdentity probable

GPT-5.1-Codex

OpenAIfamily · GPT 5.1developers.openai.com/api/docs/models/gpt-5.1-co

A version of GPT-5.1 optimized for agentic coding in Codex.

Open in Graph
data quality74

Updated 6 h ago · first seen 11 Sept 2026

model_01M293VC59AGHGMC4F9791V5E1

Overview

Identity

Canonical model
Yesidentity confidence: mediumOne row per real model release. Artifacts (checkpoints, quantisations, conversions) and folded evaluation variants point here.
Official checkpoints
None recorded — closed weightsofficial_checkpoints = hf_repo identifiers carried by the model itself; artifacts are separate entities pointing here through canonical_id.
Artifacts
None recordedSeparate entities (checkpoint · quantization · conversion · packaging) pointing to this model through canonical_id.
Provider deployments
2
API aliases
gpt-5-1-codexgpt-5.1-codexopenai/gpt-5.1-codexIdentifiers under which providers and evaluators refer to this model.
Folded evaluation variants
0Effort / thinking variants (…-high, …-non-reasoning) are result configurations of this model, not separate models. Their old URLs redirect here.

Openness

Closed / proprietary— weights not available; 7 dimensions unknown.

Weights are not available; the model is reachable only through an API or a product.

  • Weights

    No

  • Inference code

    —

  • Training code

    —

  • Training data

    —

  • Dataset

    —

  • Commercial use

    —

  • Redistribution

    —

  • Derivatives

    —

dimensions marked null are unknown, not false

Key facts

Release date

Source:OpenRouter public model & pricing listingT2observed 16 h agomedium

Status

Source:OpenAI Platform docsT1observed 16 h agohigh

Deprecation date

Source:OpenAI Platform docsT1observed 16 h agohigh

Retirement date

Source:OpenAI Platform docsT1observed 16 h agohigh

Official page
developers.openai.com/api/docs/models/gpt-5.1-codex

Source:OpenAI Platform docsT1observed 16 h agohigh

API model id

Source:OpenAI Platform docsT1observed 16 h agohigh

Openrouter id

Source:OpenRouter public model & pricing listingT2observed 16 h agomedium

Architecture

Tokenizer

Source:OpenRouter public model & pricing listingT2observed 16 h agomedium

Capabilities

Modalities

Modalities
imagetext
Input
imagetext
Output
text

Capabilities

  • Tool calling

    Yes

    OpenRouter public model & pricing listing · T2

  • Structured output

    Yes

    OpenRouter public model & pricing listing · T2

  • Reasoning

    Yes

    OpenRouter public model & pricing listing · T2

  • Vision

    Yes

    OpenRouter public model & pricing listing · T2

  • Audio

    Unavailable

  • Fine-tuning available

    Unavailable

Context window

Source:OpenRouter public model & pricing listingT2observed 16 h agomedium

Max output

Source:OpenRouter public model & pricing listingT2observed 16 h agomedium

Tokenizer

Source:OpenRouter public model & pricing listingT2observed 16 h agomedium

Benchmarks15

Compare with another model →

Comparable same task and conditions · Partially comparable same task, conditions differ (effort, temperature, judge) · Not comparable different variant or metric

Benchmark results grouped by comparability group
Benchmark · groupBest scoreTrustConfigurationResultsvs leaderEvaluatedSource
Terminal-Benchagentic · accuracy · variant=hard · evaluator=Artificial AnalysisIndependentevaluatorArtificial Analysisvarianthardreasoning_efforthighconditions differ across rows → partially comparable2−31.1 ptvs gpt-5.6-solobs. 12 Sept 2026artificialanalysis.aiT2
τ²-benchagentic · pass^1 · variant=Telecom · evaluator=Artificial AnalysisIndependentevaluatorArtificial AnalysisvariantTelecomreasoning_efforthighconditions differ across rows → partially comparable1non-primary groupobs. 12 Sept 2026artificialanalysis.aiT2
τ²-benchagentic · pass^1 · evaluator=Artificial AnalysisIndependentevaluatorArtificial Analysis1−16.1 ptvs Z.ai GLM 5.2obs. 11 Sept 2026artificialanalysis.aiT2
SWE-bench Verifiedcoding · resolved · board=Verified · system=mini-SWE-agentOfficial boardboardVerifiedsystemmini-SWE-agentreasoning_effortmediumconditions differ across rows → partially comparable1−10.8 ptvs Claude Opus 4.524 Nov 2025swebench.comT2
Artificial Analysis Intelligence Indexcomposite · indexIndependentreasoning_efforthighversion4.3conditions differ across rows → partially comparable2−29.7vs Claude Fable 5.1obs. 12 Sept 2026artificialanalysis.aiT2
IFBenchinstruction-following · accuracy · evaluator=Artificial AnalysisIndependentevaluatorArtificial Analysisreasoning_efforthighconditions differ across rows → partially comparable2−13.3 ptvs Grok 4.3obs. 12 Sept 2026artificialanalysis.aiT2
Humanity's Last Examknowledge · accuracy · evaluator=Artificial AnalysisIndependentevaluatorArtificial Analysisreasoning_efforthighconditions differ across rows → partially comparable2−33.4 ptvs Claude Fable 5.1obs. 12 Sept 2026artificialanalysis.aiT2
MMMU-Promultimodal · accuracy · evaluator=Artificial AnalysisIndependentevaluatorArtificial Analysisreasoning_efforthighconditions differ across rows → partially comparable2−14.4 ptvs gpt-6-astraobs. 12 Sept 2026artificialanalysis.aiT2
GPQA Diamondreasoning · accuracy · variant=Diamond · evaluator=Artificial AnalysisIndependentevaluatorArtificial AnalysisvariantDiamondreasoning_efforthighconditions differ across rows → partially comparable1non-primary groupobs. 12 Sept 2026artificialanalysis.aiT2
GPQA Diamondreasoning · accuracy · variant=GPQA Diamond · evaluator=Artificial AnalysisIndependentevaluatorArtificial AnalysisvariantGPQA Diamond1−10.3 ptvs gpt-6-astraobs. 11 Sept 2026artificialanalysis.aiT2

Current rows only, grouped by benchmark → canonical metric → comparability group (task configuration). Effort variants folded into this model appear as rows of the same group. 15 current rows in total. “vs leader” compares with the current leader of the benchmark's primary group only; other groups are not directly comparable. Comparability rules →

Providers & Pricing2

All offers in the price terminal →
Provider deployments, cheapest output first
ProviderContextInput / 1MCached inOutput / 1MStatusObservedSource
OpenAI APIcheapest outputopenai/gpt-5.1-codex400Kout 128K$0.13active6 h agosince 11 Sept 2026openrouter.aiT2
OpenRouteropenai/gpt-5.1-codex400Kout 128K$0.13active12 min agosince 12 Sept 2026openrouter.aiT2

USD per 1M tokens as published by each provider; native units (per-request fees, flex/priority tiers) are kept verbatim. Rows are append-only — every price change is kept in the history below. Cost of a workload →

Price history

Step lines per provider; amber markers are recorded changes. Click a marker or a row for the evidence behind that price.

Output price · USD / 1M tokens 2 providers

Output price history of GPT-5.1-Codex$0$2$4$6$8$10$12Sept 26Sept 26Sept 26Sept 26Sept 26OpenAI API: first observed → $10 · 11 Sept 2026OpenRouter: first observed → $10 · 12 Sept 2026
  • OpenAI API
  • OpenRouter
  • OpenRouterfirst observed $1012 Sept 2026
  • OpenAI APIfirst observed $1011 Sept 2026

Input price · USD / 1M tokens 2 providers

Input price history of GPT-5.1-Codex$0$0.50$1$1.5Sept 26Sept 26Sept 26Sept 26Sept 26OpenAI API: first observed → $1.25 · 11 Sept 2026OpenRouter: first observed → $1.25 · 12 Sept 2026
  • OpenAI API
  • OpenRouter
  • OpenRouterfirst observed $1.2512 Sept 2026
  • OpenAI APIfirst observed $1.2511 Sept 2026

Versions & Artifacts0

Version history

Context windowfirst observation only

11 Sept 2026current

Max outputfirst observation only

11 Sept 2026current

Opennessfirst observation only

11 Sept 2026current

Statusfirst observation only

11 Sept 2026current

Each hop is a claim: click a value for its source, tier and observation time. Nothing is overwritten — a new observation closes the previous claim.

Artifacts 0

No artifact (checkpoint, quantisation, conversion or packaging) points to this model yet.

Timeline8

Full timeline →

Change history

Temporal, append-only claims: a new observation closes the previous claim instead of overwriting it. Rewind the record with the as-of picker.
1 claims · 1 propertiesShow all properties

Weights availableweights_available1

Claim history for Weights available
ValueValid from → toStatusSourceConfidenceExtractor
No → currentcurrentAI Atlas curated registry (YAML, versioned in git, every entry carries its source URL)T2highderived

Claims are temporal and append-only: a new observation closes the previous claim (valid_to) instead of overwriting it. Conflicting claims from different sources are kept side by side and flagged — never averaged. Methodology →

Provenance

Attributed facts

26

Source tiers

T1T28 / 18

Freshest observation

6 h ago

Conflicts

1 flagged

Source documents 5

Source documents
SourceDocumentTypeTierLast observedSnapshots
OpenAI Platform docsdevelopers.openai.com/api/docs/deprecations.md model_docsT1· Official14 min ago2
OpenAI Platform docsdevelopers.openai.com/api/docs/models.md model_docsT1· Official14 min ago1
OpenRouter public model & pricing listingopenrouter.ai/api/v1/models catalogueT2· Quality secondary12 min ago12
SWE-bench leaderboardsswebench.com/ leaderboardT2· Quality secondary5 h ago1
Artificial Analysisartificialanalysis.ai/leaderboards/models leaderboardT2· Quality secondary6 h ago2

Tier 1 = official/primary, 2 = quality secondary, 3 = community, 4 = unverified. Every snapshot is archived; see all sources and the methodology.

Data quality (74/100) measures how well AI Atlas knows this entity — completeness, primary-source ratio, freshness, conflicts — never how good the model is. Methodology →