DeepSeek V4-Pro vs Mistral Medium 3.5

DeepSeek · China  |  Mistral AI · France · Updated June 2026

Quick verdict

Pick DeepSeek V4-Pro for open-weight 1.6t moe (~49b active) — deepseek's largest, self-hostable or 1m-token context with up to 384k output tokens. Pick Mistral Medium 3.5 for strong intelligence-for-size — artificial analysis intelligence index 30, near the top of its price tier or 128b dense open-weight model — self-hostable. On a tight budget at scale, DeepSeek V4-Pro is the value pick.

DeepSeek V4-Pro (DeepSeek, China) and Mistral Medium 3.5 (Mistral AI, France) line up two different AI ecosystems against each other — a comparison that is as much about cost philosophy and openness as raw capability. DeepSeek V4-Pro is deepSeek's 1.6-trillion-parameter open-weight model at $0.435/$0.87 — strong open-weight coding and a 1M context at a fraction of flagship prices. Mistral Medium 3.5 is mistral's efficient 128B open-weight model — a single dense model unifying reasoning and coding that punches above its size on independent tests (AA Index 30). They diverge most on price and context window — each quantified below from the models' real specs.

Key differences at a glance

Side-by-side specs

SpecDeepSeek V4-ProMistral Medium 3.5
ProviderDeepSeek (China) Mistral AI (France)
ReleasedApril 24, 2026 April 29, 2026
Context window1M (~1,500 pages) 256K (~384 pages)
Price (in/out)$0.435/$0.87 per 1M tokens $1.5/$7.5 per 1M tokens
Open weight?Yes — self-hostable Yes — self-hostable
Modalitiestext, code text, image, code
SWE-Bench VerifiedNot published Not published
MRCR v2 @ 1MNot published Not published

Who wins what

Open-weight 1.6T MoE (~49B active) — DeepSeek's largest, self-hostable

DeepSeek V4-Pro

DeepSeek's 1.6-trillion-parameter open-weight model at $0.435/$0.87 — strong open-weight coding and a 1M context at a fraction of flagship prices — and it runs cheaper at $0.435/$0.87 per 1M tokens.

1M-token context with up to 384K output tokens

DeepSeek V4-Pro

Its 1M window holds about 3.9× more than Mistral Medium 3.5's 256K in a single prompt.

Permanent low pricing at $0.435/$0.87 per million, set May 2026

DeepSeek V4-Pro

Mistral Medium 3.5 is comparatively weak here — output pricing ($7.50/M) is higher than the cheapest Chinese rivals

Strong intelligence-for-size — Artificial Analysis Intelligence Index 30, near the top of its price tier

Mistral Medium 3.5

Mistral's efficient 128B open-weight model — a single dense model unifying reasoning and coding that punches above its size on independent tests (AA Index 30) — and it is the newer of the two.

128B dense open-weight model — self-hostable

Mistral Medium 3.5

Mistral Medium 3.5 lists 128B dense open-weight model — self-hostable among its strengths; DeepSeek V4-Pro does not.

Unifies reasoning and coding into one model with an adjustable reasoning effort

Mistral Medium 3.5

Mistral Medium 3.5 lists unifies reasoning and coding into one model with an adjustable reasoning effort among its strengths; DeepSeek V4-Pro does not.

Lowest cost at scale

DeepSeek V4-Pro

At $0.435/$0.87 per 1M tokens, it is the cheaper of the two — the gap dominates the bill on high-volume workloads.

Largest single-prompt input

DeepSeek V4-Pro

Its 1M window is about 3.9× larger than Mistral Medium 3.5's 256K, fitting roughly 1,500 pages in one prompt.

Which should you pick?

A cost-sensitive startup shipping high volume

DeepSeek V4-Pro

At $0.435/$0.87 per 1M tokens it undercuts Mistral Medium 3.5, and on millions of tokens that margin decides the monthly bill.

Someone analysing very long documents or codebases

DeepSeek V4-Pro

Larger 1M window fits more in one prompt.

Anyone whose priority is open-weight 1.6t moe (~49b active) — deepseek's largest, self-hostable

DeepSeek V4-Pro

It is specifically built for that.

Anyone whose priority is strong intelligence-for-size — artificial analysis intelligence index 30, near the top of its price tier

Mistral Medium 3.5

That is its strongest area.

An enterprise with regional data-residency rules

Mistral Medium 3.5 or DeepSeek V4-Pro

Origin (China vs France) affects where data is processed and which compliance regime applies — check the provider's terms for your region.

DeepSeek V4-Pro: where it fits

DeepSeek's 1.6-trillion-parameter open-weight model at $0.435/$0.87 — strong open-weight coding and a 1M context at a fraction of flagship prices. Released April 24, 2026 by DeepSeek, it is built for open-weight 1.6T MoE (~49B active) — DeepSeek's largest, self-hostable, 1M-token context with up to 384K output tokens, permanent low pricing at $0.435/$0.87 per million, set May 2026, and sources place it near the top of open-weight coding, around 80 on SWE-Bench Verified.

Its trade-offs are real: independent SWE-Bench Verified placement is inconsistent across sources, pro and Pro-Max variants are quoted with different scores, text and code only — no image, audio or video, and overlaps DeepSeek V4 and V3.2 already in this comparison. At $0.435 in / $0.87 out per million tokens, it sits in the budget price band.

Mistral Medium 3.5: where it fits

Mistral's efficient 128B open-weight model — a single dense model unifying reasoning and coding that punches above its size on independent tests (AA Index 30). Released April 29, 2026 by Mistral AI, it is built for strong intelligence-for-size — Artificial Analysis Intelligence Index 30, near the top of its price tier, 128B dense open-weight model — self-hostable, unifies reasoning and coding into one model with an adjustable reasoning effort, and 256K context with text and image input.

Its trade-offs: below the absolute frontier — a value/efficiency pick, not a flagship-beater, output pricing ($7.50/M) is higher than the cheapest Chinese rivals, license framing ('open' vs enterprise) varies across sources — confirm terms for commercial use, and no native video or audio. At $1.5 in / $7.5 out per million tokens, it sits in the mid price band.

The bottom line for this matchup

This is less "which is smarter" and more "which ecosystem fits." DeepSeek V4-Pro (China) and Mistral Medium 3.5 (France) differ on pricing philosophy, data-residency, and tooling as much as on raw scores. DeepSeek V4-Pro is the cheaper option, which matters at volume. The pragmatic move is to run one real task through both and judge the outputs against your own constraints — including where your data is allowed to be processed.

Want both DeepSeek V4-Pro and Mistral Medium 3.5 without two subscriptions? LumiChats gives you these plus 40+ models under one ₹69/day pass (about $1/day) — draft with one, cross-check with the other.

See pricing

Frequently asked questions

Is DeepSeek V4-Pro or Mistral Medium 3.5 better for coding?

Public SWE-Bench figures are not available for either model, so the honest test is your own repository — run an identical real bug through both. By design, DeepSeek V4-Pro leans toward open-weight 1.6t moe (~49b active) — deepseek's largest, self-hostable while Mistral Medium 3.5 leans toward strong intelligence-for-size — artificial analysis intelligence index 30, near the top of its price tier, and that positioning usually predicts which feels better on your codebase.

Which is cheaper, DeepSeek V4-Pro or Mistral Medium 3.5?

DeepSeek V4-Pro is cheaper — $0.435/$0.87 per 1M tokens vs $1.5/$7.5 per 1M tokens, roughly 3.4× apart on input.

Which has the bigger context window?

DeepSeek V4-Pro — 1M vs 256K, about 3.9× larger. Useful only if the model actually reasons over the full window, which not all do.

Can I use both DeepSeek V4-Pro and Mistral Medium 3.5 together?

Yes — a multi-model platform like LumiChats gives you DeepSeek V4-Pro, Mistral Medium 3.5 and 40+ others under one ₹69/day pass (about $1/day), so you can draft with one and cross-check with the other instead of buying two subscriptions.

Which is newer, DeepSeek V4-Pro or Mistral Medium 3.5?

Mistral Medium 3.5 — released April 29, 2026, about 5 days after DeepSeek V4-Pro.

Related comparisons

Specifications and benchmarks reflect publicly reported figures as of June 2026 and may change as providers release updates. Always verify on your own workload.