Question 1

What does this GPT-5.3 Codex vs MiMo-V2.5-Pro-UltraSpeed 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-5.3 Codex or MiMo-V2.5-Pro-UltraSpeed?

Accepted Answer

GPT-5.3 Codex lists $1.75 input and $14.00 output per 1M tokens. MiMo-V2.5-Pro-UltraSpeed lists $1.305 input and $2.61 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-5.3 Codex or MiMo-V2.5-Pro-UltraSpeed?

Accepted Answer

GPT-5.3 Codex lists 400K tokens and MiMo-V2.5-Pro-UltraSpeed lists 1.05M. MiMo-V2.5-Pro-UltraSpeed therefore has the larger recorded context window, but capacity alone is not a quality score.

Question 4

Which is faster: GPT-5.3 Codex or MiMo-V2.5-Pro-UltraSpeed?

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-5.3 Codex and MiMo-V2.5-Pro-UltraSpeed support?

Accepted Answer

GPT-5.3 Codex records text, image, pdf input and text output. MiMo-V2.5-Pro-UltraSpeed records text 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-5.3 Codex or MiMo-V2.5-Pro-UltraSpeed?

Accepted Answer

Consider MiMo-V2.5-Pro-UltraSpeed if you need larger context or larger maximum output or a lower listed input rate or a lower listed output rate. MiMo-V2.5-Pro-UltraSpeed offers downloadable weights; GPT-5.3 Codex 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	GPT-5.3 Codex	MiMo-V2.5-Pro-UltraSpeed
Provider	OpenAI	Xiaomi
Listed pricing route	OpenAI	Xiaomi
Model family	gpt-codex	mimo
Accepted inputs	text, image, pdf	text
Produced outputs	text	text
Context window	400K	1.05MHigher
Max output	128K	131.07KHigher
Input price / 1M	$1.75	$1.305Lower
Output price / 1M	$14.00	$2.61Lower
Reasoning mode	Documented	Documented
Tool calling	Documented	Documented
Image input	Documented	Not documented
Audio input	Not documented	Not documented
Structured output	Documented	Not documented
License	Proprietary	Open weights

GPT-5.3 Codex vs MiMo-V2.5-Pro-UltraSpeed

GPT-5.3 Codex

MiMo-V2.5-Pro-UltraSpeed

Key differences

Pricing, limits and capabilities

Which model should you choose?

Documentation and model profiles

Questions people ask

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