DeepSeek V4 Pro vs Mistral Medium 3.5

Choose DeepSeek V4 Pro if you want…

• ✓Higher intelligence (Artificial Analysis index 44)
• ✓Lower price ($0.54 / 1M blended)
• ✓Larger context window (1.0M)

Choose Mistral Medium 3.5 if you want…

• ✓Faster output (~132.8 tokens/sec)

DeepSeek V4 Pro

DeepSeek V4 Pro makes a compelling case that frontier-class coding performance and a one-million-token context window do not have to cost frontier-class money. At roughly $0.18 per million tokens blended, it runs 10x cheaper on input and 30x cheaper on output than comparable models, while posting an 80.6% score on SWE-Bench Verified — the highest reported among open-weight models at launch. Users consistently praise its agentic coding ability, noting it competes with or beats larger closed models on multi-step coding tasks, and its hybrid attention architecture handles full-codebase analysis without collapsing under the token budget. The MIT license is a genuine differentiator: weights are freely available for self-hosting, fine-tuning, and commercial integration. The honest caveat: V4 Pro is verbose. It can generate four to five times more output tokens than comparable models on the same prompt, which erodes the per-token savings and makes cost estimation harder than it first appears. Still in preview as of mid-2026, with all benchmark scores currently vendor-reported, it is best suited for teams comfortable with that tradeoff.

Mistral Medium 3.5

Mistral Medium 3.5 is Mistral's multimodal flagship on just4o.chat, served through the Vercel AI Gateway as mistral/mistral-medium-3.5. It combines frontier text reasoning with native image understanding in a single model, so you can hand it a screenshot, chart, or document image alongside your prompt and get a grounded answer back. A 256k-token context window handles long inputs comfortably, and function calling makes it suitable for agentic and tool-driven work. It is a Premium model on just4o.chat, billed at 3 premium requests per send before length multipliers, reflecting its higher provider output price of $7.50 per million tokens ($1.50 per million input). The honest trade-offs: no native web search, and as a vision-capable generalist rather than a dedicated reasoning model, it does not expose a step-by-step thinking budget the way Magistral does. For multimodal analysis, visual document work, and high-quality general assistance where image input matters, it is the model to reach for.