Mistral: Mistral Medium 3.5 (batch) vs OpenAI: GPT-5

Neither wins outright: Mistral: Mistral Medium 3.5 (batch) is the pick when cost matters at scale, OpenAI: GPT-5 when you need to fit long inputs in one request.

Key numbers

SpecMistral: Mistral Medium 3.5 (batch)OpenAI: GPT-5
ProviderMistral AIOpenAI
Input price (per 1M tokens)$0.75$1.25
Output price (per 1M tokens)$3.75$10.00
Blended price (3:1 input/output)$1.50$3.44
Cheaper than … of all models we track31%19%
Context window262K tokens (~393 pages)400K tokens (~600 pages)
Larger context than … of all models48%63%
Max output per response210K tokens (~157,300 words)128K tokens (~96,000 words)
Input typestext, image, filetext, image, file
Output typestexttext
Free variantNoNo
Listed since2026-04-302025-08-07
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What it costs for real workloads

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-5Difference
Customer-support chatbot
50,000 conversations — each a 6-turn conversation (1,500 in / 400 out tokens)
$131$294Mistral: Mistral Medium 3.5 (batch) saves $163
RAG search over documents
20,000 questions — each a question answered from ~8 retrieved passages (6,000 in / 500 out tokens)
$127$250Mistral: Mistral Medium 3.5 (batch) saves $123
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$270Mistral: Mistral Medium 3.5 (batch) saves $135
Batch summarisation
10,000 documents — each a 6,000-word report summarised to a page (8,000 in / 600 out tokens)
$82.50$160Mistral: Mistral Medium 3.5 (batch) saves $77.50
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$72.50Mistral: Mistral Medium 3.5 (batch) saves $31.25

Capabilities side by side

CapabilityMistral: Mistral Medium 3.5 (batch)OpenAI: GPT-5What it lets you do
Tool / function calling✓ Yes✓ Yescall your APIs and run agent loops
Structured output (JSON schema)✓ Yes✓ Yesreturn JSON that validates against your schema
Reasoning / thinking mode✓ Yes✓ Yesspend extra tokens thinking before answering hard problems
Image input✓ Yes✓ Yesread screenshots, charts and scanned pages
Audio input——take speech or audio directly
File / PDF input✓ Yes✓ Yesaccept documents without your own parsing step
Image output——generate images, not just text
Built-in web search—✓ Yesanswer from live web results
Seed (reproducible sampling)✓ Yes✓ Yesrepeat 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

Which should you choose?

Choose Mistral: Mistral Medium 3.5 (batch) if…

  • cost matters at scale — it is 56% cheaper on a typical 3:1 input/output mix ($131 vs $294 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, 9 months after the other

Choose OpenAI: GPT-5 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?

Neither wins outright: Mistral: Mistral Medium 3.5 (batch) is the pick when cost matters at scale, OpenAI: GPT-5 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 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?

Mistral: Mistral Medium 3.5 (batch) is cheaper: $1.50 vs $3.44 per 1M tokens at a typical 3:1 input/output mix, 56% less. For 50,000 support conversations a month that is $131 against $294.

How much do Mistral: Mistral Medium 3.5 (batch) and OpenAI: GPT-5 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 costs $1.25 input and $10.00 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?

OpenAI: GPT-5: 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 support function calling and JSON output?

Tool calling — Mistral: Mistral Medium 3.5 (batch): yes, OpenAI: GPT-5: yes. JSON-schema structured output — Mistral: Mistral Medium 3.5 (batch): yes, OpenAI: GPT-5: yes.

Can Mistral: Mistral Medium 3.5 (batch) or OpenAI: GPT-5 read images?

Yes, both accept image input.

Is Mistral: Mistral Medium 3.5 (batch) or OpenAI: GPT-5 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?

Mistral: Mistral Medium 3.5 (batch) can write up to 210K tokens (about 157,300 words) per response; OpenAI: GPT-5 up to 128K (about 96,000 words).

When were Mistral: Mistral Medium 3.5 (batch) and OpenAI: GPT-5 released?

Mistral: Mistral Medium 3.5 (batch) was listed on 2026-04-30; OpenAI: GPT-5 on 2025-08-07.

About the two models

OpenAI

OpenAI: GPT-5

GPT-5 is OpenAI’s most advanced model, offering major improvements in reasoning, code quality, and user experience. It is optimized for complex tasks that require step-by-step reasoning, instruction following, and accuracy...

Full OpenAI: GPT-5 specs →

Compare Mistral: Mistral Medium 3.5 (batch) with other models

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