GPT-5.1-Codex-Mini
OpenAI · released Nov 13, 2025
- Type
- Proprietary
- Input
- None held
- Output
- None held
- Cached
- None held
We don't hold a list price for this model yet · hosted only — we hold no downloadable copy
Our take
Written Aug 3, 2026GPT-5.1-Codex-Mini is a compact coding specialist from OpenAI that can handle up to 400,000 tokens in a single request and accepts both text and images. It is built for long-context coding workflows, particularly in web development, though its measured quality rests on a single benchmark type.
Pick this for long-context coding workflows where you need 400,000 tokens of working memory, or for web development tasks where the Arena Code (WebDev) leaderboard is your relevant quality signal. Use it on Azure if you need guaranteed throughput at 77 tokens per second. Skip it if you need evidence of general chat, reasoning, or non-web coding ability, or if you want to run the model on your own hardware.
The case for it
- Extremely long context for a coding model: up to 400,000 tokens in a single request.
- Stable leaderboard presence with tight score clustering: six consecutive daily readings within a spread of only 0.1215 points.
The case against it
- Thin benchmark coverage — only one task type measured, with no general chat, reasoning, or multilingual coding scores.
- No throughput data on OpenRouter, and modest speed on Azure at 77 tokens per second.
- Output costs several times more than input, with no cheaper tier available.
How good is it?
IntelligencePuzzles, maths, exam questions
Nobody we watch has scored GPT-5.1-Codex-Mini for this. We would take the rating from Arena Text (overall).
CodingWriting and fixing code on its own
GPT-5.1-Codex-Mini is not on Arena Coding, which is where the rating would come from, so there is no rating here. It is on Arena Code (WebDev), in 67th of 74 with 1244.2.
AgenticPlanning, calling tools, staying on task
Nobody we watch has scored GPT-5.1-Codex-Mini for this. We would take the rating from Arena Agent (IPS).
WritingWe do not rate this
Nobody we watch has scored this model for writing. Two boards come close and neither tests writing: Arena Creative Writing asks people which of two replies they prefer, and LiveBench Language tests whether a model understood a passage.
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.
Or rent it from someone else
Cheapest of 2 live listings. Picked at the widest standard context we hold, within one quantisation slice, so the numbers beside it are a price one host actually charges.
- per 1M tokens
- $0.25 in / $2.00 out
- Context served
- 400K
- Throughput
- Not measured
| Provider | In / out per 1M tokens | Context | Throughput | Trains on prompts | Logs prompts | Zero retention |
|---|---|---|---|---|---|---|
| OpenRouter | $0.25 / $2.00 | 400K | not measured | Unknown | Unknown | Unknown |
| Microsoft Azure AI | $0.25 / $2.00 | 400K | 39 tok/s | No | No | Confirmed |
Microsoft Azure AIAcross the 2 listings we hold: 1 say they do not train on prompts, 0 say they do and 1 do not say. 1 appear in the zero-retention registry we check; the rest are unknown to us rather than confirmed either way.
What each host's API supports
From the parameter list each endpoint publishes. Streaming is omitted: nothing we hold reports it, for any model.
- ✓
- Supported
- ✗
- Not supported
- Not published
- host gave no parameter list
| Provider | Tool calling | JSON output | Strict schema |
|---|---|---|---|
| OpenRouter | ✓ | ✓ | ✓ |
| Microsoft Azure AI | ✓ | ✓ | ✓ |
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
Dates behind this page
Prices last checked 9d ago
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 do not say whether they train on prompts.
- We don't hold a list price for this model yet — the gap is ours, not the lab's.
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
Commercial API terms. We hold no licence record for this model, so there is nothing to summarise here.
Identifiers
- Modality record
- text+image->text
- Catalogue slug
- openai-gpt-5-1-codex-mini