Question 1

What does this GPT-4.1 mini vs GPT-5.1 Codex Max 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: GPT-4.1 mini or GPT-5.1 Codex Max?

Accepted Answer

GPT-4.1 mini lists $0.40 input and $1.60 output per 1M tokens. GPT-5.1 Codex Max lists $1.25 input and $10.00 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: GPT-4.1 mini or GPT-5.1 Codex Max?

Accepted Answer

GPT-4.1 mini lists 1.05M tokens and GPT-5.1 Codex Max lists 400K. GPT-4.1 mini therefore has the larger recorded context window, but capacity alone is not a quality score.

Question 4

Which is faster: GPT-4.1 mini or GPT-5.1 Codex Max?

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 GPT-4.1 mini and GPT-5.1 Codex Max support?

Accepted Answer

GPT-4.1 mini records text, image, pdf input and text output. GPT-5.1 Codex Max 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 GPT-4.1 mini or GPT-5.1 Codex Max?

Accepted Answer

Consider GPT-4.1 mini if you need larger context or a lower listed input rate or a lower listed output rate. Consider GPT-5.1 Codex Max if you need larger maximum output. 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	GPT-4.1 mini	GPT-5.1 Codex Max
Provider	OpenAI	OpenAI
Listed pricing route	OpenAI	OpenAI
Model family	gpt-mini	gpt-codex
Accepted inputs	text, image, pdf	text, image
Produced outputs	text	text
Context window	1.05MHigher	400K
Max output	32.77K	128KHigher
Input price / 1M	$0.40Lower	$1.25
Output price / 1M	$1.60Lower	$10.00
Reasoning mode	Not documented	Documented
Tool calling	Documented	Documented
Image input	Documented	Documented
Audio input	Not documented	Not documented
Structured output	Documented	Documented
License	Proprietary	Proprietary

GPT-4.1 mini vs GPT-5.1 Codex Max

GPT-4.1 mini

GPT-5.1 Codex Max

Key differences

Pricing, limits and capabilities

Which model should you choose?

Documentation and model profiles

Questions people ask

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