Mistral Large 3 675B Instruct vs o3-pro
Mistral Large 3 675B Instruct (2025) and o3-pro (2025) are frontier reasoning models from MistralAI and OpenAI. Mistral Large 3 675B Instruct ships a 128k-token context window, while o3-pro ships a 200k-token context window. On Google-Proof Q&A, o3-pro leads by 40.1 pts. On pricing, Mistral Large 3 675B Instruct costs $0.50/1M input tokens versus $20/1M for the alternative. This comparison covers specs, pricing, API access, capabilities, benchmarks, input and output token costs, and production fit for coding and agent workloads.
Mistral Large 3 675B Instruct is ~3900% cheaper at $0.50/1M; pay for o3-pro only for coding workflow support.
Decision scorecard
Local evidence first| Signal | Mistral Large 3 675B Instruct | o3-pro |
|---|---|---|
| Best for | multimodal apps and provider-routed production | reasoning-heavy apps, multimodal apps, and tool-calling agents |
| Decision fit | Coding, RAG, and Agents | Coding, RAG, and Agents |
| Context window | 128k | 200k |
| Cheapest output | $1.50/1M tokens | $80/1M tokens |
| Provider routes | 6 tracked | 3 tracked |
| Shared benchmarks | 1 shared | Google-Proof Q&A leader |
Decision tradeoffs
- Mistral Large 3 675B Instruct has the lower cheapest tracked output price at $1.50/1M tokens.
- Mistral Large 3 675B Instruct has broader tracked provider coverage for fallback and procurement flexibility.
- Local decision data tags Mistral Large 3 675B Instruct for Coding, RAG, and Agents.
- o3-pro holds a shared-benchmark lead on Google-Proof Q&A, ahead by 40.1 points.
- o3-pro has the larger context window for long prompts, retrieval packs, or transcript analysis.
- o3-pro uniquely exposes Reasoning, Function calling, and Tool use in local model data.
- Local decision data tags o3-pro for Coding, RAG, and Agents.
Monthly cost at traffic
Estimate token spend from the cheapest tracked input and output route or tier on this page.
Mistral Large 3 675B Instruct
$775
Cheapest tracked route/tier: OpenRouter
o3-pro
$36,000
Cheapest tracked route/tier: OpenRouter
Estimated monthly gap: $35,225. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.
Switch friction
- Provider overlap exists on OpenRouter and Vercel AI Gateway; start route-level A/B tests there.
- o3-pro is $78.50/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
- o3-pro adds Reasoning, Function calling, and Tool use in local capability data.
- Provider overlap exists on OpenRouter and Vercel AI Gateway; start route-level A/B tests there.
- Mistral Large 3 675B Instruct is $78.50/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
- Check replacement coverage for Reasoning, Function calling, and Tool use before moving production traffic.
Specs
| Specification | ||
|---|---|---|
| Released | 2025-12-01 | 2025-06-10 |
| Context window | 128k | 200k |
| Parameters | 675B | — |
| Architecture | Decoder Only | Decoder Only |
| License | Apache 2.0OSI-approved | Proprietary |
| Openness | Open source | Proprietary |
| Commercial use | Commercial use: permitted | Commercial use: conditional |
| Knowledge cutoff | 2024-11 | 2025-08 |
Pricing and availability
| Pricing attribute | Mistral Large 3 675B Instruct | o3-pro |
|---|---|---|
| Input price | $0.50/1M tokens | $20/1M tokens |
| Output price | $1.50/1M tokens | $80/1M tokens |
| Providers |
Capabilities
| Capability | Mistral Large 3 675B Instruct | o3-pro |
|---|---|---|
| Vision | Yes | Yes |
| Multimodal | Yes | Yes |
| Reasoning | No | Yes |
| Function calling | No | Yes |
| Tool use | No | Yes |
| Structured outputs | Yes | Yes |
| Code execution | No | Yes |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
| Benchmark | Mistral Large 3 675B Instruct | o3-pro |
|---|---|---|
| Google-Proof Q&A | 43.9 | 84.0 |
Deep dive
On shared benchmark coverage, Google-Proof Q&A has Mistral Large 3 675B Instruct at 43.9 and o3-pro at 84, with o3-pro ahead by 40.1 points. The largest visible gap is 40.1 points on Google-Proof Q&A, which matters most when that benchmark mirrors your workload. Treat isolated benchmark wins as directional, because provider routing, prompt style, and tool access can move real application results.
The capability footprint differs most on reasoning mode: o3-pro, function calling: o3-pro, tool use: o3-pro, and code execution: o3-pro. Both models share vision, multimodal input, and structured outputs, so the practical split is not just feature count. Use those differences to decide whether the page is about raw model quality, agentic coding support, multimodal ingestion, or predictable structured API behavior.
For cost, Mistral Large 3 675B Instruct lists $0.50/1M input and $1.50/1M output tokens on the cheapest tracked provider, while o3-pro lists $20/1M input and $80/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts Mistral Large 3 675B Instruct lower by about $37.20 per million blended tokens. Availability is 6 providers versus 3, so concentration risk also matters.
Choose Mistral Large 3 675B Instruct when vision-heavy evaluation, lower input-token cost, and broader provider choice are central to the workload. Choose o3-pro when coding workflow support and larger context windows are more important. For production, rerun your own prompts through the exact provider, region, and tool stack you plan to ship.
FAQ
Which has a larger context window, Mistral Large 3 675B Instruct or o3-pro?
o3-pro supports 200k tokens, while Mistral Large 3 675B Instruct supports 128k tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible.
Which is cheaper, Mistral Large 3 675B Instruct or o3-pro?
Mistral Large 3 675B Instruct is cheaper on tracked token pricing. Mistral Large 3 675B Instruct costs $0.50/1M input and $1.50/1M output tokens. o3-pro costs $20/1M input and $80/1M output tokens. Provider discounts or batch pricing can still change the final bill.
Is Mistral Large 3 675B Instruct or o3-pro open source?
Mistral Large 3 675B Instruct is listed under Apache 2.0. o3-pro is listed under Proprietary. License labels affect whether you can self-host, redistribute weights, or rely only on hosted APIs, so confirm the upstream license before deployment.
Which is better for vision, Mistral Large 3 675B Instruct or o3-pro?
Both Mistral Large 3 675B Instruct and o3-pro expose vision. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface.
Which is better for multimodal input, Mistral Large 3 675B Instruct or o3-pro?
Both Mistral Large 3 675B Instruct and o3-pro expose multimodal input. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface.
Where can I run Mistral Large 3 675B Instruct and o3-pro?
Mistral Large 3 675B Instruct is available on OpenRouter, AWS Bedrock, NVIDIA NIM, Mistral AI Studio, and Microsoft Foundry. o3-pro is available on OpenRouter, OpenAI API, and Vercel AI Gateway. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
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Last reviewed: 2026-06-19. Data sourced from public model cards and provider documentation.