Head to head
Grok 4.3 vs Mistral Medium 3.5
Grok 4.3 (xAI) and Mistral Medium 3.5 (Mistral) compared on intelligence, speed, context, and price — and which to choose. Both run on just4o.chat from one chat.
| Metric | Grok 4.3 | Mistral Medium 3.5 |
|---|---|---|
| Intelligence (AA index) | 38 ✓ | 30 |
| Output speed (tokens/sec) | 129.3 ✓ | 101.8 |
| Context window | 1M ✓ | 256K |
| Max output | 1M | — |
| Input price / 1M | $1.25 ✓ | $1.5 |
| Output price / 1M | $2.5 ✓ | $7.5 |
| Released | 2026-04 | 2026-04 |
Choose Grok 4.3 if you want…
- Higher intelligence (Artificial Analysis index 38)
- Faster output (~129.3 tokens/sec)
- Lower price ($1.56 / 1M blended)
- Larger context window (1M)
Choose Mistral Medium 3.5 if you want…
- A comparable all-rounder — they trade blows on the headline metrics.
Grok 4.3
Grok 4.3 made a deliberate trade: xAI stopped chasing frontier performance and built something more practical instead. The result is a model that earns its keep through native X/Twitter integration — pulling posts seconds old when news breaks — and a 1 million token context window that handles entire codebases or lengthy regulatory documents in a single pass. At $1.25 per million input tokens, it arrives 40-60% cheaper than its predecessor Grok-4, and users find real value in its DeepSearch mode, which combines live web data with X discussions in a way that rivals Perplexity for current-events research. Frontend developers report genuinely polished web UI output, moving past the "cheap AI demo" look. The honest trade-off: creative writers consistently find it too literal and verbose, and its 16-second time-to-first-token sits at the high end for reasoning models in this price range. If your work is anchored in real-time information or long-document analysis rather than narrative craft, Grok 4.3 offers a focused, cost-sensible tool.
Full Grok 4.3 details →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.
Full Mistral Medium 3.5 details →FAQ
Which is better, Grok 4.3 or Mistral Medium 3.5?
Grok 4.3 leads on 4 of the headline metrics (higher intelligence (artificial analysis index 38); faster output (~129.3 tokens/sec); lower price ($1.56 / 1m blended); larger context window (1m)), while Mistral Medium 3.5 wins on other factors. The right pick depends on whether you prioritise capability, speed, or cost.
Is Grok 4.3 or Mistral Medium 3.5 cheaper?
Grok 4.3 is cheaper at $1.56 per 1M tokens (blended), versus $3.
Can I use both Grok 4.3 and Mistral Medium 3.5?
Yes. Both are available on just4o.chat from a single chat — you can switch between them per message with no separate subscriptions.