GPT-5.1-Codex-Mini
OpenAI · released Nov 13, 2025
- Type
- Closed
- Input
- None held
- Output
- None held
- Cached
- None held
We don't hold a list price for this model yet · hosted only — we have no record of published weights
Our take
Written Sep 2, 2026GPT-5.1-Codex-Mini is a compact coding specialist from OpenAI that accepts both text and images to generate code, with a 400,000-token request limit that fits large codebases. It scores well on human-judged web-app building tasks, though its output rate is steep relative to its input.
Pick this for long-context coding workflows where the 400,000-token limit fits large codebases, or for turning UI mockups and diagrams into working code. Use it when web-app building quality matters and you have measured scores to trust. Skip it if you need cheaper output rates, verified speed on every provider you use, or any benchmark beyond web development.
The case for it
- 400,000-token request limit among the longest we hold for a coding model.
- Multimodal input: accepts images alongside text for code generation tasks.
- Arena Code (WebDev) score 1243.44 from human votes, evaluated September 2026.
The case against it
- Output rate is eight times the input rate on every tracked provider, with no cheaper tier.
- Throughput unverified on one of two providers; only Azure is measured at 58.5 tokens per second.
- Parameter count undisclosed, so efficiency claims cannot be checked.
How good is it?
EverydayGeneral questions and everyday reasoning
Not yet scored on Arena Text (overall).
CodingWriting and fixing code on its own
Not yet scored on Arena Coding. It is on Arena Code (WebDev), in 88th of 95 with 1244.
AgenticPlanning, calling tools, staying on task
Not yet scored on Arena Agent.
WritingDrafting and rewriting prose
Not yet scored on Arena Creative Writing.
Every published score for this model1 scoreEvery figure we hold, from 1 board, with who ran it and a link to the source — including the boards no rating above is built on.
Where to rent it
Prices checked 4 hours ago — each listing carries its own date.
- per 1M tokens
- $0.25 in / $2.00 out
- Context served
- 400K
- Throughput
- ~61 tok/s
| Provider | In / out per 1M tokens | Context | Throughput | Trains on prompts | Logs prompts | Zero retention |
|---|---|---|---|---|---|---|
| OpenRouterOpenRouter's own listing | $0.25 / $2.00checked 4 hours ago | 400K | not measured | Unknown | Unknown | Unknown |
| Microsoft Azure AIThrough OpenRouter | $0.25 / $2.00checked 4 hours ago | 400K128K max reply | 61 tok/s | No | No | Confirmed |
OpenRouterAcross the 2 listings we hold: 1 says it does not train on prompts, 0 say they do and 1 does not say. 1 appears in the zero-retention registry we check; the rest are unknown to us.
What each host's API supports
From the parameter list each endpoint publishes. Streaming is omitted: nothing we hold reports it, for any model.
| Provider | Tool calling | JSON output | Strict schema |
|---|---|---|---|
| OpenRouterOpenRouter's own listing | ✓ | ✓ | ✓ |
| Microsoft Azure AIThrough OpenRouter | ✓ | ✓ | ✓ |
Tool calling: 2 of 2 listings say yes. JSON output: 2 of 2 listings say yes. Strict schema: 2 of 2 listings say yes.
When we formed this view
Recent changes
What moved
first indexed by our pipelineEach date is the day we first saw the change, or the day the maker announced it.
What we do not know about this model yet
- Nothing we hold says whether an endpoint streams, so we do not show it either way.
- 1 of 2 listings does not say whether it trains on prompts.
- We don't hold a list price for this model yet — the gap is ours, not the lab's.
- We hold no batch or off-peak rate for any of its listings.
Licence and identifiers
What the licence allowsWe hold no licence record for this model. Inside are the identifiers you need to pull it — its Hugging Face repo where we have one, our slug and a machine-readable card.
Licence
We hold no licence record for this model, and no record of published weights either — so we can neither summarise its terms nor point you at the weights.
Identifiers
- Takes in, gives back
- Text and images in, text out
- Catalogue slug
- openai-gpt-5-1-codex-mini