GPT-5.1 Codex
Nov 2025
GPT-5.1 CodexCompare inon
Benchmarks of GPT-5.1 Codex22
BenchmarkByScoreRank
Overall1
Knowledge4
Science2
Coding3
Multimodal1
Documents1
Legacy · saturated or no longer reported10
No benchmark matches
Rankingat high effort?
Retired models are left out of the current rankings.
Alternatives?
ModelScoreCostPer taskWhat changes
CheaperMuse Spark 1.3max×2-42%$1.60Only auto tool_choice is supported+5BetterGPT-6 Lunamedium+26%-94%$0.017Function calling only with none · Chat Completions+3
OpenMiMo v2.6 Prothinking+95%-84%$0.13Pass back reasoning_content+3
CheaperGrok 4.7xhigh+96%-13%$3.74Reasoning cannot be disabled+4
CheaperQwen3.8 Max (0902)thinking+92%-13%$5.41ModelScoreCostPer taskWhat changes
Muse Spark 1.3max×2-42%$1.60Only auto tool_choice is supported+5Grok 4.7xhigh+96%-13%$3.74Reasoning cannot be disabled+4MiMo v2.6 ProthinkingOpen+95%-84%$0.13Pass back reasoning_content+3Qwen3.8 Max (0902)thinking+92%-13%$5.41
DeepSeek V4.1 Flash 1017maxOpen+90%-85%$0.26Pass back reasoning_content · Chat Completions+4ModelScoreCostPer taskWhat changes
GPT-6 Lunamedium+26%-94%$0.017Function calling only with none · Chat Completions+3
Claude Haiku 5.5low+24%-94%$0.024Remove sampling parameters+5GPT-5.6 Lunahigh+36%-87%$0.044MiMo v2.5 ProthinkingOpen+10%-84%$0.054No image inputMiMo v2.6 FlashthinkingOpen+60%-95%$0.062Pass back reasoning_content+3ModelScoreCostPer taskWhat changes
MiMo v2.6 ProthinkingOpen+95%-84%$0.13Pass back reasoning_content+3DeepSeek V4.1 Flash 1017maxOpen+90%-85%$0.26Pass back reasoning_content · Chat Completions+4
GLM 5.3maxOpen+89%-37%$2.01No image input+4
Step 5 PreviewthinkingOpen+85%-59%$1.03web_search not available · Chat Completions+2
Kimi K3maxOpen+84%+75%$2.00Sampling parameters are fixed+3ModelScoreCostPer taskWhat changes
GPT-6 Astrahigh×2.1—$1.73Monitoring can return HTTP 403+2GPT-6.1 Solhigh×2.1—$0.32Remove unsupported parameters+5GPT-6 Solhigh+79%—$0.37GPT-5.6 Solhigh+79%—$0.81GPT-5.5high+56%—$1.54Prompts with >272K input tokensGPT-5.6 Terrahigh+44%—$0.34Prompts with >272K input tokensGPT-6 Lunahigh+39%—$0.029Function calling only with none · Chat Completions+3GPT-5.3 Codexxhigh+37%—$1.75 / $14DeprecatedAll OpenAI models →History
4 versionsBenchmarks
all categoriesChat & Knowledge
Coding
Agents & Tool Use
Writing & Language
Vision & Documents
FAQ
How much does GPT-5.1 Codex cost?›
$1.25 per 1M input tokens and $10 per 1M output tokens (cheapest host: Azure).
Is GPT-5.1 Codex free to use?›
There is no free API; the cheapest paid price is $1.25 per 1M input tokens.
How can I use GPT-5.1 Codex?›
Through the API of Azure.
What is the context window of GPT-5.1 Codex?›
400K tokens, with up to 128K output tokens.
When was GPT-5.1 Codex released? Is there a newer version?›
Released 2025-11-13. It has been superseded by GPT-5.6 Sol.
Is GPT-5.1 Codex open source?›
No, GPT-5.1 Codex is a closed model available through an API. The closest open-weights option here is MiMo v2.6 Pro.
Can GPT-5.1 Codex read images?›
It accepts text and images as input.
What is GPT-5.1 Codex?›
GPT-5.1 Codex is a closed language model from OpenAI, released Nov 2025.
What are the best alternatives to GPT-5.1 Codex?›
Muse Spark 1.3 (cheaper), GPT-6 Luna (better), MiMo v2.6 Pro (open weights).