Grok 4.5 vs Mistral Medium 3

xAI · US  |  Mistral AI · France · Updated June 2026

Quick verdict

Pick Grok 4.5 for cheap, token-efficient agentic coding — about gpt-5.5-codex quality at roughly half the cost or extreme token efficiency — around 4x fewer output tokens per task than opus 4.8. Pick Mistral Medium 3 for strong cost-to-capability at $0.40/$2.00 or general reasoning, coding and multimodal tasks. On a tight budget at scale, Mistral Medium 3 is the value pick.

Grok 4.5 (xAI, US) and Mistral Medium 3 (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. Grok 4.5 is xAI's first coding-focused model — pitched as Opus-class but faster, more token-efficient, and cheaper, undercutting GPT-5.5-Codex. Mistral Medium 3 is mistral's mid-tier model at $0.40/$2.00 — efficient general capability with a 128K window, below the 1M-context frontier tier. 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

SpecGrok 4.5Mistral Medium 3
ProviderxAI (US) Mistral AI (France)
ReleasedJuly 8, 2026 May 7, 2025
Context window500K (~750 pages) 128K (~192 pages)
Price (in/out)$2/$6 per 1M tokens $0.4/$2 per 1M tokens
Open weight?No — API only No — API only
Modalitiestext, image, code text, image, code
SWE-Bench VerifiedNot published Not published
MRCR v2 @ 1MNot published Not published

Who wins what

Cheap, token-efficient agentic coding — about GPT-5.5-Codex quality at roughly half the cost

Grok 4.5

Its 500K window holds about 3.9× more than Mistral Medium 3's 128K in a single prompt.

Extreme token efficiency — around 4x fewer output tokens per task than Opus 4.8

Grok 4.5

XAI's first coding-focused model — pitched as Opus-class but faster, more token-efficient, and cheaper, undercutting GPT-5.5-Codex — and it carries the larger 500K context.

In-IDE coding, trained on real Cursor developer sessions and shipped natively in Cursor

Grok 4.5

XAI's first coding-focused model — pitched as Opus-class but faster, more token-efficient, and cheaper, undercutting GPT-5.5-Codex — and it is the newer of the two.

Strong cost-to-capability at $0.40/$2.00

Mistral Medium 3

At $0.4/$2 per 1M tokens it undercuts Grok 4.5 ($2/$6 per 1M tokens), and that gap compounds at volume.

General reasoning, coding and multimodal tasks

Mistral Medium 3

Mistral's mid-tier model at $0.40/$2.00 — efficient general capability with a 128K window, below the 1M-context frontier tier — and it runs cheaper at $0.4/$2 per 1M tokens.

Efficient mid-tier deployment for production workloads

Mistral Medium 3

Mistral Medium 3 lists efficient mid-tier deployment for production workloads among its strengths; Grok 4.5 does not.

Lowest cost at scale

Mistral Medium 3

At $0.4/$2 per 1M tokens, it is the cheaper of the two — the gap dominates the bill on high-volume workloads.

Largest single-prompt input

Grok 4.5

Its 500K window is about 3.9× larger than Mistral Medium 3's 128K, fitting roughly 750 pages in one prompt.

Which should you pick?

A cost-sensitive startup shipping high volume

Mistral Medium 3

At $0.4/$2 per 1M tokens it undercuts Grok 4.5, and on millions of tokens that margin decides the monthly bill.

Someone analysing very long documents or codebases

Grok 4.5

Larger 500K window fits more in one prompt.

Anyone whose priority is cheap, token-efficient agentic coding — about gpt-5.5-codex quality at roughly half the cost

Grok 4.5

It is specifically built for that.

Anyone whose priority is strong cost-to-capability at $0.40/$2.00

Mistral Medium 3

That is its strongest area.

An enterprise with regional data-residency rules

Grok 4.5 or Mistral Medium 3

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

Grok 4.5: where it fits

XAI's first coding-focused model — pitched as Opus-class but faster, more token-efficient, and cheaper, undercutting GPT-5.5-Codex. Released July 8, 2026 by xAI, it is built for cheap, token-efficient agentic coding — about GPT-5.5-Codex quality at roughly half the cost, extreme token efficiency — around 4x fewer output tokens per task than Opus 4.8, in-IDE coding, trained on real Cursor developer sessions and shipped natively in Cursor, and top-tier placement on the Artificial Analysis Intelligence Index.

Its trade-offs are real: smaller 500K context (halved from the 1M generation), with pricing that doubles above 200K tokens, and eU launch delayed; no open weights. At $2 in / $6 out per million tokens, it sits in the mid price band.

Mistral Medium 3: where it fits

Mistral's mid-tier model at $0.40/$2.00 — efficient general capability with a 128K window, below the 1M-context frontier tier. Released May 7, 2025 by Mistral AI, it is built for strong cost-to-capability at $0.40/$2.00, general reasoning, coding and multimodal tasks, efficient mid-tier deployment for production workloads, and text and image input.

Its trade-offs: a 128K context — smaller than the 1M-window flagships here, no published SWE-Bench Verified score, a mid-tier model, not a frontier reasoner, and proprietary, unlike Mistral's open-weight releases. At $0.4 in / $2 out per million tokens, it sits in the budget price band.

The bottom line for this matchup

This is less "which is smarter" and more "which ecosystem fits." Grok 4.5 (US) and Mistral Medium 3 (France) differ on pricing philosophy, data-residency, and tooling as much as on raw scores. Mistral Medium 3 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 Grok 4.5 and Mistral Medium 3 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 Grok 4.5 or Mistral Medium 3 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, Grok 4.5 leans toward cheap, token-efficient agentic coding — about gpt-5.5-codex quality at roughly half the cost while Mistral Medium 3 leans toward strong cost-to-capability at $0.40/$2.00, and that positioning usually predicts which feels better on your codebase.

Which is cheaper, Grok 4.5 or Mistral Medium 3?

Mistral Medium 3 is cheaper — $2/$6 per 1M tokens vs $0.4/$2 per 1M tokens, roughly 5× apart on input.

Which has the bigger context window?

Grok 4.5 — 500K vs 128K, about 3.9× larger. Useful only if the model actually reasons over the full window, which not all do.

Can I use both Grok 4.5 and Mistral Medium 3 together?

Yes — a multi-model platform like LumiChats gives you Grok 4.5, Mistral Medium 3 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, Grok 4.5 or Mistral Medium 3?

Grok 4.5 — released July 8, 2026, about 14 months after Mistral Medium 3.

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.