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Models/OpenAI

GPT-5.1 Codex

Codex GPT for repository edits, code review, and practical software agents

Source-linked gpt-codex Closed weights Released 2025-11-13
API data Report
Input modalitiesT
Output modalitiesT
Input price$1.07/1M tokens
Output price$8.5/1M tokens
Context window400K
Max output128K
Overview

Capabilities and specifications

✓ Reasoning Yes
✓ Tool calling Yes
? Structured output Unknown
✓ Attachments Yes
✓ Vision input Yes
× Open weights No
Creator
OpenAI
Model family
gpt-codex
Knowledge cutoff
2024-09-30
License
Not documented
Release date
2025-11-13
Model ID
openai/gpt-5.1-codex
Inference availability

Provider pricing and availability

Provider-specific identifiers, limits, and prices per million tokens.

Report a price
Providers offering GPT-5.1 Codex
ProviderProvider model IDContextInputOutputCache readCapabilitiesSource
OpenCode Zen gpt-5.1-codex 400K $1.07 $8.5 $0.107 ReasoningToolsJSON Docs
Poe openai/gpt-5.1-codex 400K $1.1 $9 $0.11 ReasoningTools Docs
Requesty openai/gpt-5.1-codex 400K $1.25 $10 $0.125 ReasoningToolsJSON Docs
Vercel AI Gateway openai/gpt-5.1-codex 400K $1.25 $10 $0.13 ReasoningToolsJSON Docs
Vivgrid gpt-5.1-codex 400K $1.25 $10 $0.125 ReasoningToolsJSON Docs
ZenMux openai/gpt-5.1-codex 400K $1.25 $10 $0.12 ReasoningTools Docs
OpenAI gpt-5.1-codex 400K $1.25 $10 $0.125 ReasoningToolsJSON Docs
OrcaRouter openai/gpt-5.1-codex 400K $1.25 $10 $0.125 ReasoningToolsJSON Docs
LLM Gateway gpt-5.1-codex 400K $1.25 $10 $0.125 ReasoningToolsJSON Docs
Abacus gpt-5.1-codex 400K $1.25 $10 $0.125 ReasoningToolsJSON Docs
Cloudflare AI Gateway openai/gpt-5.1-codex 400K $1.25 $10 $0.125 ReasoningToolsJSON Docs
Azure gpt-5.1-codex 400K $1.25 $10 $0.125 ReasoningToolsJSON Docs
Kilo Gateway openai/gpt-5.1-codex 400K $1.25 $10 $0.125 ReasoningTools Docs
OpenRouter openai/gpt-5.1-codex 400K $1.25 $10 $0.13 ReasoningToolsJSON Docs
Azure Cognitive Services gpt-5.1-codex 400K $1.25 $10 $0.125 ReasoningToolsJSON Docs
AIHubMix gpt-5.1-codex 400K $1.25 $10 $0.125 ReasoningToolsJSON Docs
NanoGPT openai/gpt-5.1-codex 400K $1.25 $10 - Reasoning Docs

Capability badges appear only when the provider catalog explicitly lists support.

Serving quality

Performance and reliability

Observed serving measurements stay separate from model specifications and are never estimated from price or model size.

Throughput Not reported

Generation speed; higher is faster.

Latency / TTFT Not reported

Time until the first output token arrives.

Uptime Not reported

Successful requests over a measured period.

Performance varies by inference provider, region, and load. Provider-level measurements appear only when a source reports them.

Published evaluations

Benchmarks

Raw results remain attached to their original source and version.

Benchmark registry
Design Arena: codecategories - Unversioned - eloTop 8 reported models
Kimi K3
1418.0
Claude Opus 5
1358.0
Z.ai: GLM 5.2
1346.0
Anthropic: Claude Fable 5 (batch)
1340.0
Claude Fable 5
1340.0
Anthropic: Claude Opus 4.6 (batch)
1324.0
Anthropic: Claude Opus 4.6
1324.0
GPT-5.1 Codex
1181.0
Design Arena: dataviz - Unversioned - eloTop 8 reported models
Kimi K3
1382.0
Claude Opus 5
1378.0
Z.ai: GLM 5.1
1366.0
Google: Gemini 3.6 Flash (batch)
1350.0
Gemini 3.6 Flash
1350.0
Anthropic: Claude Fable 5 (batch)
1349.0
Claude Fable 5
1349.0
GPT-5.1 Codex
1202.0
Design Arena: fullstack - Unversioned - eloTop 8 reported models
Anthropic: Claude Opus 4.7 (batch)
1503.0
Anthropic: Claude Opus 4.7
1503.0
Anthropic: Claude Fable 5 (batch)
1293.0
Claude Fable 5
1293.0
Anthropic: Claude Opus 4.8 (batch)
1289.0
Anthropic: Claude Opus 4.8
1289.0
xAI: Grok 4.5
1282.0
GPT-5.1 Codex
1086.0
Design Arena: gamedev - Unversioned - eloTop 8 reported models
Anthropic: Claude Fable 5 (batch)
1393.0
Claude Fable 5
1393.0
Z.ai: GLM 5.2
1358.0
Anthropic: Claude Sonnet 5 (batch)
1352.0
Claude Sonnet 5
1352.0
OpenAI: GPT-5.5 (batch)
1345.0
GPT-5.5
1345.0
GPT-5.1 Codex
1195.0
Design Arena: mobileapps - Unversioned - eloTop 8 reported models
Anthropic: Claude Opus 4.6 (batch)
1275.0
Anthropic: Claude Opus 4.6
1275.0
Anthropic: Claude Opus 4.8 (batch)
1272.0
Anthropic: Claude Opus 4.8
1272.0
Anthropic: Claude Sonnet 4.6
1267.0
Anthropic: Claude Fable 5 (batch)
1265.0
Claude Fable 5
1265.0
GPT-5.1 Codex
1192.0
Design Arena: webapps - Unversioned - eloTop 8 reported models
Kimi K3
1329.0
Anthropic: Claude Fable 5 (batch)
1305.0
Claude Fable 5
1305.0
Anthropic: Claude Sonnet 5 (batch)
1304.0
Claude Sonnet 5
1304.0
Anthropic: Claude Opus 4.7 (batch)
1303.0
Anthropic: Claude Opus 4.7
1303.0
GPT-5.1 Codex
1071.0
Design Arena: website - Unversioned - eloTop 8 reported models
Kimi K3
1375.0
Claude Opus 5
1343.0
Z.ai: GLM 5.2
1340.0
Anthropic: Claude Fable 5 (batch)
1323.0
Claude Fable 5
1323.0
xAI: Grok 4.5
1323.0
Google: Gemini 3.6 Flash (batch)
1322.0
GPT-5.1 Codex
1186.0
Catalog activity

Recent record changes

Detected changes from successful source imports.

Full change log
Price Completion10.0 → 8.5
Price Prompt1.25 → 1.07
Price Completion8.5 → 10.0
Price Prompt1.07 → 1.25
Price Completion10.0 → 8.5
Price Prompt1.25 → 1.07
Price Completion8.5 → 10.0
Price Prompt1.07 → 1.25
Public API

Use this record

Fetch the complete source-linked model record without an API key.

API documentation
Endpoint
GET https://www.modelbench.lol/api/v1/models/openai/gpt-5.1-codex
curl
curl "https://www.modelbench.lol/api/v1/models/openai/gpt-5.1-codex"