GPT-5.1 vs Mistral Large 3
OpenAI · US | Mistral · France · Updated June 2026
Quick verdict
Pick GPT-5.1 for adaptive reasoning that scales compute to task difficulty or general-purpose reasoning, coding and tool use. Pick Mistral Large 3 for open-weight (apache 2.0), self-hostable or strong multilingual performance. Choose Mistral Large 3 if you need self-hosting or data privacy; GPT-5.1 if you want a managed API.
GPT-5.1 (OpenAI, US) and Mistral Large 3 (Mistral, France) line up two different AI ecosystems against each other — a comparison that is as much about cost philosophy and openness as raw capability. GPT-5.1 is openAI's late-2025 GPT-5.1 at $1.25/$10 — a capable general model since surpassed by the GPT-5.2–5.6 line. Mistral Large 3 is france's frontier contender — strong multilingual model with European data residency. They diverge most on price, context window and open vs. closed weights — each quantified below from the models' real specs.
Key differences at a glance
- ▸Price: Mistral Large 3 is about 2.5× cheaper on input ($0.5/$1.5 per 1M tokens vs $1.25/$10 per 1M tokens) — meaningful once you are processing millions of tokens a month.
- ▸Context window: GPT-5.1 holds 1.6× more — 400K (~600 pages) vs 256K (~384 pages). But effective recall usually fades long before the advertised ceiling, so the bigger number only helps if the model reasons over it.
- ▸Recency: Mistral Large 3 is the newer model by about 19 days (released December 2, 2025), usually meaning fresher training data and capabilities.
- ▸Ecosystem: this is a US-vs-France matchup — they differ in pricing philosophy, data-residency options, and tooling ecosystems, not only benchmarks.
Side-by-side specs
| Spec | GPT-5.1 | Mistral Large 3 |
|---|---|---|
| Provider | OpenAI (US) | Mistral (France) |
| Released | November 13, 2025 | December 2, 2025 |
| Context window | 400K (~600 pages) | 256K (~384 pages) |
| Price (in/out) | $1.25/$10 per 1M tokens | $0.5/$1.5 per 1M tokens |
| Open weight? | No — API only | Yes — self-hostable |
| Modalities | text, image, code | text, image, code |
| SWE-Bench Verified | Not published | Not published |
| MRCR v2 @ 1M | Not published | Not published |
Who wins what
Adaptive reasoning that scales compute to task difficulty
GPT-5.1
OpenAI's late-2025 GPT-5.1 at $1.25/$10 — a capable general model since surpassed by the GPT-5.2–5.6 line — and it carries the larger 400K context.
General-purpose reasoning, coding and tool use
GPT-5.1
GPT-5.1 lists general-purpose reasoning, coding and tool use among its strengths; Mistral Large 3 does not.
A large ~400K context for long documents and sessions
GPT-5.1
Its 400K window holds about 1.6× more than Mistral Large 3's 256K in a single prompt.
Open-weight (Apache 2.0), self-hostable
Mistral Large 3
Open weights make this possible at all — GPT-5.1 is API-only, so it cannot leave the vendor's servers.
Strong multilingual performance
Mistral Large 3
France's frontier contender — strong multilingual model with European data residency — and it runs cheaper at $0.5/$1.5 per 1M tokens.
Efficient inference
Mistral Large 3
France's frontier contender — strong multilingual model with European data residency — and its weights are open while GPT-5.1 is API-only.
Lowest cost at scale
Mistral Large 3
At $0.5/$1.5 per 1M tokens, it is the cheaper of the two — the gap dominates the bill on high-volume workloads.
Largest single-prompt input
GPT-5.1
Its 400K window is about 1.6× larger than Mistral Large 3's 256K, fitting roughly 600 pages in one prompt.
Which should you pick?
A cost-sensitive startup shipping high volume
→ Mistral Large 3
At $0.5/$1.5 per 1M tokens it undercuts GPT-5.1, and on millions of tokens that margin decides the monthly bill.
Someone analysing very long documents or codebases
→ GPT-5.1
Larger 400K window fits more in one prompt.
A team with data-privacy or self-hosting needs
→ Mistral Large 3
Open weights let you run it on your own hardware; GPT-5.1 is API-only.
Anyone whose priority is adaptive reasoning that scales compute to task difficulty
→ GPT-5.1
It is specifically built for that.
Anyone whose priority is open-weight (apache 2.0), self-hostable
→ Mistral Large 3
That is its strongest area.
An enterprise with regional data-residency rules
→ GPT-5.1 or Mistral Large 3
Origin (US vs France) affects where data is processed and which compliance regime applies — check the provider's terms for your region.
GPT-5.1: where it fits
OpenAI's late-2025 GPT-5.1 at $1.25/$10 — a capable general model since surpassed by the GPT-5.2–5.6 line. Released November 13, 2025 by OpenAI, it is built for adaptive reasoning that scales compute to task difficulty, general-purpose reasoning, coding and tool use, a large ~400K context for long documents and sessions, and text and image input.
Its trade-offs are real: superseded by GPT-5.2 through GPT-5.6 — kept for compatibility rather than being current, no reliably published SWE-Bench Verified figure, exact context window unconfirmed (400K vs 410K across trackers), and premium output price at $10/1M for a now-older model. At $1.25 in / $10 out per million tokens, it sits in the mid price band.
Mistral Large 3: where it fits
France's frontier contender — strong multilingual model with European data residency. Released December 2, 2025 by Mistral, it is built for open-weight (Apache 2.0), self-hostable, strong multilingual performance, efficient inference, and function calling.
Its trade-offs: smaller context than US/China frontier, and less benchmark coverage. At $0.5 in / $1.5 out per million tokens, it sits in the budget price band.
The bottom line for this matchup
The defining split here is open vs. closed. Mistral Large 3 gives you weights you control — self-host it, fine-tune it, keep data in-house, pay only for hardware. GPT-5.1 gives you a managed, always-updated API with no infrastructure to run. Teams with GPUs, privacy requirements, or huge volume often favour the open model; teams that want zero ops and the latest capabilities favour the closed one. Capability is close enough that this operational question, not the benchmark, usually decides it.
Want both GPT-5.1 and Mistral Large 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 pricingFrequently asked questions
Is GPT-5.1 or Mistral Large 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, GPT-5.1 leans toward adaptive reasoning that scales compute to task difficulty while Mistral Large 3 leans toward open-weight (apache 2.0), self-hostable, and that positioning usually predicts which feels better on your codebase.
Which is cheaper, GPT-5.1 or Mistral Large 3?
Mistral Large 3 is open-weight, so self-hosting means no per-token fee (you pay for hardware instead), while GPT-5.1 is API-metered at $1.25/$10 per 1M tokens. For most teams without GPUs, the API model is cheaper to start; at very high volume, self-hosting can win.
Which has the bigger context window?
GPT-5.1 — 400K vs 256K, about 1.6× larger. Useful only if the model actually reasons over the full window, which not all do.
Can I use both GPT-5.1 and Mistral Large 3 together?
Yes — a multi-model platform like LumiChats gives you GPT-5.1, Mistral Large 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, GPT-5.1 or Mistral Large 3?
Mistral Large 3 — released December 2, 2025, about 19 days after GPT-5.1.
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.