OpenAI model product
GPT-5.1-Codex
1-Codex is an OpenAI model optimized for agentic coding tasks in Codex or similar environments.
Updated Sep 8, 2026. Default version: GPT-5.1 Codex
LLMBoard Score48.8GPT-5.1 Codex
Coverage0%3 benchmark families
Context window400KTokens
Official input priceN/AOfficial price unavailable
GPT-5.1-Codex Capability Profile
This profile uses the model's current scored version. Arena ratings and prices are shown separately.
GPT-5.1-Codex Benchmark Results
Benchmark scores for GPT-5.1 Codex.
Sort by
Benchmark | Score | Rank | Participants | Percentile | Evidence | Evaluated |
|---|
| BenchmarkSWE-Lancer | Score66.30% | Rank01 | Participants4 | Percentile100.00% | EvidenceC | Evaluated |
| BenchmarkTerminal-Bench 2.0 | Score52.80% | Rank32 | Participants51 | Percentile38.00% | EvidenceC | Evaluated |
| BenchmarkSWE-Bench Verified | Score73.70% | Rank43 | Participants113 | Percentile62.50% | EvidenceC | Evaluated |
| BenchmarkLM Arena Webdev | Score1,335.84 rating | Rank79 | Participants97 | Percentile18.75% | EvidenceA | Evaluated |
GPT-5.1-Codex Arena Results
Preference and agent-evaluation results for the default version.
Sort by
Arena | Category | Rank | Rating / score | Votes | Observations | Result date |
|---|
| Arenawebdev | Categoryoverall | Rank79 | Rating / score1,335.84 | Votes4,865 | ObservationsN/A | Result date |
| Arenawebdev | Categorywebdev | Rank79 | Rating / score1,335.84 | Votes4,865 | ObservationsN/A | Result date |
| Arenawebdev | Categorywebdev-html | Rank79 | Rating / score1,345.31 | Votes4,849 | ObservationsN/A | Result date |
GPT-5.1-Codex Pricing
Official vendor API pricing appears first, followed by individual provider offers.
- Official API
- N/A
- Official provider
- N/A
- Lowest third-party
- From $1.07 input, $8.5 output per 1M via OpenCode Zen
- Tracked offerings
- 17
Sort by
Provider | Provider model ID | Region | Input / 1M | Output / 1M | Context | Updated |
|---|
| ProviderOpenCode Zen | Provider model IDgpt-5.1-codex | Regionglobal | Input / 1M$1.07 | Output / 1M$8.5 | Context400K | Updated |
| ProviderPoe | Provider model IDopenai/gpt-5.1-codex | Regionglobal | Input / 1M$1.1 | Output / 1M$9 | Context400K | Updated |
| ProviderJiekou.AI | Provider model IDgpt-5.1-codex | Regionglobal | Input / 1M$1.13 | Output / 1M$9 | Context400K | Updated |
| ProviderOrcaRouter | Provider model IDopenai/gpt-5.1-codex | Regionglobal | Input / 1M$1.25 | Output / 1M$10 | Context400K | Updated |
| ProviderNanoGPT | Provider model IDopenai/gpt-5.1-codex | Regionglobal | Input / 1M$1.25 | Output / 1M$10 | Context400K | Updated |
| ProviderImpossibl | Provider model IDopenai/gpt-5.1-codex | Regionglobal | Input / 1M$1.25 | Output / 1M$10 | Context400K | Updated |
| ProviderOpenRouter | Provider model IDopenai/gpt-5.1-codex | Regionglobal | Input / 1M$1.25 | Output / 1M$10 | Context400K | Updated |
| ProviderVivgrid | Provider model IDgpt-5.1-codex | Regionglobal | Input / 1M$1.25 | Output / 1M$10 | Context400K | Updated |
| ProviderZenMux | Provider model IDopenai/gpt-5.1-codex | Regionglobal | Input / 1M$1.25 | Output / 1M$10 | Context400K | Updated |
| ProviderHelicone | Provider model IDgpt-5.1-codex | Regionglobal | Input / 1M$1.25 | Output / 1M$10 | Context400K | Updated |
| ProviderAzure Cognitive Services | Provider model IDgpt-5.1-codex | Regionglobal | Input / 1M$1.25 | Output / 1M$10 | Context400K | Updated |
| ProviderAzure | Provider model IDgpt-5.1-codex | Regionglobal | Input / 1M$1.25 | Output / 1M$10 | Context400K | Updated |
| ProviderAIHubMix | Provider model IDgpt-5.1-codex | Regionglobal | Input / 1M$1.25 | Output / 1M$10 | Context400K | Updated |
| ProviderVercel AI Gateway | Provider model IDopenai/gpt-5.1-codex | Regionglobal | Input / 1M$1.25 | Output / 1M$10 | Context400K | Updated |
| ProviderDevPass (LLM Gateway) | Provider model IDgpt-5.1-codex | Regionglobal | Input / 1M$1.25 | Output / 1M$10 | Context400K | Updated |
| ProviderKilo Gateway | Provider model IDopenai/gpt-5.1-codex | Regionglobal | Input / 1M$1.25 | Output / 1M$10 | Context400K | Updated |
| ProviderAbacus | Provider model IDgpt-5.1-codex | Regionglobal | Input / 1M$1.25 | Output / 1M$10 | Context400K | Updated |
GPT-5.1-Codex Runtime Performance
Provider-specific output speed and catalog latency for GPT-5.1 Codex. Runtime does not affect the capability score.
Sort by
Provider | Output Speed | Catalog Latency | Max Input | Max Output | Updated |
|---|
| ProviderOpenAI | Output Speed50.00 tok/s | Catalog Latency3.00 s | Max Input400K | Max Output128K | Updated |
Output Speed is generated output tokens received per second. Catalog latency is reported separately from observed provider TTFT.
GPT-5.1-Codex Specifications
Technical details for the model's default version.
- Version
- GPT-5.1 Codex
- Released
- Nov 19, 2025
- Knowledge cutoff
- Sep 30, 2024
- Parameters
- N/A
- Context window
- 400K
- Max output
- 128K
- Inputs
- image, text
- Outputs
- text
- Open weights
- No
- License
- Proprietary
GPT-5.1-Codex Versions
Available versions of this model. The score column identifies the version used in the overall ranking.
Sort by
Version | Released | LLMBoard | Parameters | Context | Max output | Open weights | License |
|---|
| VersionGPT-5.1 Codex | Released | LLMBoard48.81 | ParametersN/A | Context400K | Max output128K | Open weightsNo | LicenseProprietary |
| VersionGPT-5.1 Codex High | Released | LLMBoardN/A | ParametersN/A | Context400K | Max output128K | Open weightsNo | LicenseProprietary |
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What is GPT-5.1-Codex?
Key information about GPT-5.1-Codex and its available data.
1 with higher reasoning capabilities for agentic coding tasks. It is available in the Responses API, and its underlying model snapshot is regularly updated.
Data as of 2026-09-08.
FAQ
Common questions about GPT-5.1-Codex.
When was GPT-5.1-Codex released?
GPT-5.1-Codex's default version was released on Nov 19, 2025.
How much does GPT-5.1-Codex cost?
No official standard PAYG price is currently available for GPT-5.1-Codex. The lowest tracked third-party offer starts at $1.07 input and $8.5 output via OpenCode Zen.
Who created GPT-5.1-Codex?
GPT-5.1-Codex was created by OpenAI.
What is the context window for GPT-5.1-Codex?
The default version has a 400K token context window.
Is GPT-5.1-Codex open weight?
No. The default version is not marked as having publicly available weights.
How many API providers offer GPT-5.1-Codex?
17 provider offerings are linked to the default version.