GPT-5.5 vs Mistral Medium 3.5

GPT-5.5 versus Mistral Medium 3.5 specifications and price.
metric	GPT-5.5	Mistral Medium 3.5
Input / 1M	$5.00	$1.50
Output / 1M	$30.00	$7.50
Context	1.1M	262K
Cost @ typical workload	$4,500/mo	$1,200/mo
Modality	text + image	text + image
Price source	list	list
Provider	OpenAI	Mistral

Which should you pick?

On a typical workload, Mistral Medium 3.5 costs $1,200/mo against GPT-5.5's $4,500/mo — roughly 3.8× 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-5.5 has the larger 1.1M-token window (~1,575 pages).

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-5.5 or Mistral Medium 3.5 cheaper?

For a typical workload (1,500 input + 500 output tokens × 200,000 requests/month), Mistral Medium 3.5 costs $1,200/mo versus $4,500/mo for GPT-5.5 — about 3.8× 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-5.5 and Mistral Medium 3.5?

On price, GPT-5.5 is $5.00/$30.00 per 1M (in/out) and Mistral Medium 3.5 is $1.50/$7.50. GPT-5.5 has the larger context window at 1.1M tokens.

More comparisons

GPT-5.5 and Mistral Medium 3.5 — full specs and price history.
API cost calculator — compare on your own workload.
All comparisons — the full head-to-head index.