Mistral: Mistral Medium 3.5 (batch) vs OpenAI: GPT-5.2 (batch)
Neither wins outright: Mistral: Mistral Medium 3.5 (batch) is the pick when cost matters at scale, OpenAI: GPT-5.2 (batch) when you need to fit long inputs in one request.
Monthly cost at list price for five common workloads. Token counts per unit are stated so you can scale them to your own traffic. A workload that does not fit a model's context window is marked rather than priced.
Workload (per month)
Mistral: Mistral Medium 3.5 (batch)
OpenAI: GPT-5.2 (batch)
Difference
Customer-support chatbot
50,000 conversations — each a 6-turn conversation (1,500 in / 400 out tokens)
$131
$206
Mistral: Mistral Medium 3.5 (batch) saves $74.38
RAG search over documents
20,000 questions — each a question answered from ~8 retrieved passages (6,000 in / 500 out tokens)
$127
$175
Mistral: Mistral Medium 3.5 (batch) saves $47.50
Coding / tool-using agent
2,000 tasks — each a multi-step task with tool calls and file context (60,000 in / 6,000 out tokens)
$135
$189
Mistral: Mistral Medium 3.5 (batch) saves $54.00
Batch summarisation
10,000 documents — each a 6,000-word report summarised to a page (8,000 in / 600 out tokens)
$82.50
$112
Mistral: Mistral Medium 3.5 (batch) saves $29.50
Long-document analysis
500 documents — each a 150-page contract or codebase read in one pass (100,000 in / 2,000 out tokens)
$41.25
$50.75
Mistral: Mistral Medium 3.5 (batch) saves $9.50
Capabilities side by side
Capability
Mistral: Mistral Medium 3.5 (batch)
OpenAI: GPT-5.2 (batch)
What it lets you do
Tool / function calling
✓ Yes
✓ Yes
call your APIs and run agent loops
Structured output (JSON schema)
✓ Yes
✓ Yes
return JSON that validates against your schema
Reasoning / thinking mode
✓ Yes
✓ Yes
spend extra tokens thinking before answering hard problems
Image input
✓ Yes
✓ Yes
read screenshots, charts and scanned pages
Audio input
—
—
take speech or audio directly
File / PDF input
✓ Yes
✓ Yes
accept documents without your own parsing step
Image output
—
—
generate images, not just text
Built-in web search
—
✓ Yes
answer from live web results
Seed (reproducible sampling)
✓ Yes
✓ Yes
repeat a generation for tests and evals
Log-probabilities
—
—
read token confidence for classification and scoring
From each model's published parameters and input/output types. “—” means not advertised, not proven absent.
Price history
Mistral: Mistral Medium 3.5 (batch): price unchanged since we started tracking it on 2026-08-29.
OpenAI: GPT-5.2 (batch): price unchanged since we started tracking it on 2026-08-07.
Which should you choose?
Choose Mistral: Mistral Medium 3.5 (batch) if…
cost matters at scale — it is 38% cheaper on a typical 3:1 input/output mix ($131 vs $206 a month for 50,000 support chats)
you generate long outputs in one go — up to 210K tokens (about 157,300 words) per response
you want the newer model — released 2026-04-30, 5 months after the other
Choose OpenAI: GPT-5.2 (batch) if…
you need to fit long inputs in one request — 400K tokens is roughly 600 pages, against 393
you need built-in web search — to answer from live web results; Mistral: Mistral Medium 3.5 (batch) does not advertise it
Frequently asked questions
Is Mistral: Mistral Medium 3.5 (batch) better than OpenAI: GPT-5.2 (batch)?
Neither wins outright: Mistral: Mistral Medium 3.5 (batch) is the pick when cost matters at scale, OpenAI: GPT-5.2 (batch) when you need to fit long inputs in one request. In short: Mistral: Mistral Medium 3.5 (batch) when cost matters at scale, you generate long outputs in one go, you want the newer model; OpenAI: GPT-5.2 (batch) when you need to fit long inputs in one request, you need built-in web search.
Which is cheaper, Mistral: Mistral Medium 3.5 (batch) or OpenAI: GPT-5.2 (batch)?
Mistral: Mistral Medium 3.5 (batch) is cheaper: $1.50 vs $2.41 per 1M tokens at a typical 3:1 input/output mix, 38% less. For 50,000 support conversations a month that is $131 against $206.
How much do Mistral: Mistral Medium 3.5 (batch) and OpenAI: GPT-5.2 (batch) cost per million tokens?
Mistral: Mistral Medium 3.5 (batch) costs $0.75 per 1M input tokens and $3.75 per 1M output tokens; OpenAI: GPT-5.2 (batch) costs $0.88 input and $7.00 output. Output tokens are billed separately, so long answers shift the gap.
Which has the bigger context window, Mistral: Mistral Medium 3.5 (batch) or OpenAI: GPT-5.2 (batch)?
OpenAI: GPT-5.2 (batch): 400K tokens, about 600 pages, against 262K (about 393 pages) for Mistral: Mistral Medium 3.5 (batch).
Do Mistral: Mistral Medium 3.5 (batch) and OpenAI: GPT-5.2 (batch) support function calling and JSON output?
Can Mistral: Mistral Medium 3.5 (batch) or OpenAI: GPT-5.2 (batch) read images?
Yes, both accept image input.
Is Mistral: Mistral Medium 3.5 (batch) or OpenAI: GPT-5.2 (batch) free to use?
No free variant is listed for either; both are pay-per-token.
What is the maximum output length of Mistral: Mistral Medium 3.5 (batch) and OpenAI: GPT-5.2 (batch)?
Mistral: Mistral Medium 3.5 (batch) can write up to 210K tokens (about 157,300 words) per response; OpenAI: GPT-5.2 (batch) up to 128K (about 96,000 words).
When were Mistral: Mistral Medium 3.5 (batch) and OpenAI: GPT-5.2 (batch) released?
Mistral: Mistral Medium 3.5 (batch) was listed on 2026-04-30; OpenAI: GPT-5.2 (batch) on 2025-12-10.
Mistral Medium 3.5 is a dense 128B instruction-following model from Mistral AI. It supports text and image inputs with text output, and is designed for agentic workflows, coding, and complex...
GPT-5.2 is the latest frontier-grade model in the GPT-5 series, offering stronger agentic and long context perfomance compared to GPT-5.1. It uses adaptive reasoning to allocate computation dynamically, responding quickly...