GPT-5.4 mini vs Kimi K2 Thinking

GPT-5.4 mini versus Kimi K2 Thinking specifications and price.
metric	GPT-5.4 mini	Kimi K2 Thinking
Input / 1M	$0.75	$0.60
Output / 1M	$4.50	$2.50
Context	400K	262K
Cost @ typical workload	$675/mo	$430/mo
Modality	text + image	Text only
Price source	list	routed
Provider	OpenAI	Moonshot

Which should you pick?

On a typical workload, Kimi K2 Thinking costs $430/mo against GPT-5.4 mini's $675/mo — roughly 1.6× cheaper. But the ranking depends on your output-to-input ratio: output is the pricier direction for both, so an output-heavy job (code generation, long answers) widens the gap while an input-heavy one (summarization, retrieval) narrows it. If you need to fit more in a single prompt, GPT-5.4 mini has the larger 400K-token window (~600 pages). Only GPT-5.4 mini accepts image input — decisive if your prompts include images.

These are list and routed market prices, not measured outcomes. Two models at the same rate can still cost different amounts to finish the same task, because verbose or reasoning-heavy models emit more tokens. That gap is exactly what measured cost-per-task captures.

Frequently asked questions

Is GPT-5.4 mini or Kimi K2 Thinking cheaper?

For a typical workload (1,500 input + 500 output tokens × 200,000 requests/month), Kimi K2 Thinking costs $430/mo versus $675/mo for GPT-5.4 mini — about 1.6× less. Because output is priced higher than input, the winner can flip if your workload writes much more or less than this; check your own numbers in the calculator.

What's the main difference between GPT-5.4 mini and Kimi K2 Thinking?

On price, GPT-5.4 mini is $0.75/$4.50 per 1M (in/out) and Kimi K2 Thinking is $0.60/$2.50. GPT-5.4 mini has the larger context window at 400K tokens. GPT-5.4 mini also accepts image input, while Kimi K2 Thinking is text-only.

More comparisons

GPT-5.4 mini and Kimi K2 Thinking — full specs and price history.
API cost calculator — compare on your own workload.
All comparisons — the full head-to-head index.