GPT-5.4 mini vs GPT-4.1 mini: cost compared

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GPT-4.1 mini is 47% cheaper on input and 64% cheaper on output than GPT-5.4 mini. Whether that makes it the right choice depends entirely on whether it does your task well enough — this page gives you the cost side of that trade, precisely.

Rates side by side

$ per million tokensGPT-5.4 miniGPT-4.1 mini
Input$0.75$0.40
Output$4.50$1.60
Cached input$0.07$0.10
Output : input ratio6.0×4.0×

What the difference is worth

Monthly cost for the same workload on each, without caching:

WorkloadGPT-5.4 miniGPT-4.1 miniDifference
Support chatbot
1,000 conversations/month · 2,000 in + 500 out each
$3.75$1.60$2.15 saved
RAG search
10,000 queries/month · 8,000 in + 400 out each
$78.00$38.40$39.60 saved
Bulk extraction
10,000 documents · 3,000 in + 300 out each
$36.00$16.80$19.20 saved
Coding agent
100 runs/month · 400,000 in + 20,000 out each
$39.00$19.20$19.80 saved

Which to use

GPT-4.1 mini if the task is well-specified and mechanical — extraction, classification, formatting, routine transformation. The saving is real and compounds with volume.

GPT-5.4 mini if the task involves genuine reasoning, long-horizon planning, or work where a wrong answer is expensive to catch. Paying 1.9× more on input is trivial compared to the cost of shipping a bad result.

Both are OpenAI models, so switching is usually a one-line change and the tokenizer is the same — which makes this a genuinely easy experiment to run. Test on your own workload before deciding.

Don't skip caching

Cached input costs $0.07 on GPT-5.4 mini and $0.10 on GPT-4.1 mini. If your prompts share a stable prefix, caching on the more expensive model can beat switching to the cheaper one outright — worth checking before you migrate anything.

Sources

OpenAI rates verified 2026-08-05 (source). OpenAI rates verified 2026-08-05 (source).