Question 1

What does this Mistral Medium 3.5 vs GPT-5.1 Codex mini comparison cover?

Accepted Answer

It brings together documented inputs and outputs, token limits, deployment terms and available pricing. When both models have source-linked, verified results on a shared benchmark, those results are shown with their individual sources. The comparison is a starting point for evaluating your own workload.

Question 2

Which is cheaper: Mistral Medium 3.5 or GPT-5.1 Codex mini?

Accepted Answer

Mistral Medium 3.5 lists $1.50 input and $7.50 output per 1M tokens. GPT-5.1 Codex mini lists $0.25 input and $2.00 output. The cheaper workload depends on the mix of input and output. Long-context tiers, caching, batch processing and retries can change the bill.

Question 3

Which has the larger context window: Mistral Medium 3.5 or GPT-5.1 Codex mini?

Accepted Answer

Mistral Medium 3.5 lists 256K tokens and GPT-5.1 Codex mini lists 400K. GPT-5.1 Codex mini therefore has the larger recorded context window, but capacity alone is not a quality score.

Question 4

Which is faster: Mistral Medium 3.5 or GPT-5.1 Codex mini?

Accepted Answer

There is no matched speed measurement for both models with the same source, host, region and date. Test the same prompts at your expected concurrency and measure time to the first useful response as well as complete task time.

Question 5

What input and output types do Mistral Medium 3.5 and GPT-5.1 Codex mini support?

Accepted Answer

Mistral Medium 3.5 records text, image input and text output. GPT-5.1 Codex mini records text, image input and text output. “Not documented” means the current source record is incomplete; it does not prove that a modality is unsupported.

Question 6

Should I choose Mistral Medium 3.5 or GPT-5.1 Codex mini?

Accepted Answer

Consider Mistral Medium 3.5 if you need larger maximum output. Consider GPT-5.1 Codex mini if you need larger context or a lower listed input rate or a lower listed output rate. Mistral Medium 3.5 offers downloadable weights; GPT-5.1 Codex mini is listed as a proprietary model. Compare licence terms and operating costs before choosing a deployment. Test both on the same representative examples and judge the output against your acceptance criteria. Include tool failures, retries and the time to a completed task.

Specification	Mistral Medium 3.5	GPT-5.1 Codex mini
Provider	Mistral AI	OpenAI
Listed pricing route	Mistral API	OpenAI
Model family	mistral-medium	gpt-codex
Accepted inputs	text, image	text, image
Produced outputs	text	text
Context window	256K	400KHigher
Max output	262.14KHigher	128K
Input price / 1M	$1.50	$0.25Lower
Output price / 1M	$7.50	$2.00Lower
Reasoning mode	Documented	Documented
Tool calling	Documented	Documented
Image input	Documented	Documented
Audio input	Not documented	Not documented
Structured output	Documented	Documented
License	Modified MIT	Proprietary

Mistral Medium 3.5 vs GPT-5.1 Codex mini

Mistral Medium 3.5

GPT-5.1 Codex mini

Key differences

Pricing, limits and capabilities

Which model should you choose?

Documentation and model profiles

Questions people ask

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