LLM Reference

Claude Opus 4.8 vs Mistral Magistral Small 2509

Claude Opus 4.8 (2026) and Mistral Magistral Small 2509 (2025) are frontier reasoning models from Anthropic and MistralAI. Claude Opus 4.8 ships a 1m-token context window, while Mistral Magistral Small 2509 ships a not-yet-sourced context window. On pricing, Mistral Magistral Small 2509 costs $0.50/1M input tokens versus $5/1M for the alternative. This comparison covers specs, pricing, capabilities, benchmarks, provider availability, and production fit.

Mistral Magistral Small 2509 is ~900% cheaper at $0.50/1M; pay for Claude Opus 4.8 only for coding workflow support.

Decision scorecard

Local evidence first
SignalClaude Opus 4.8Mistral Magistral Small 2509
Best forreasoning-heavy apps, multimodal apps, and tool-calling agentsprovider-routed production
Decision fitCoding, RAG, and AgentsGeneral
Context window1m
Cheapest output$25/1M tokens$1.50/1M tokens
Provider routes7 tracked2 tracked
Shared benchmarks0 rows0 rows

Decision tradeoffs

Choose Claude Opus 4.8 when...
  • Claude Opus 4.8 has the larger context window for long prompts, retrieval packs, or transcript analysis.
  • Claude Opus 4.8 has broader tracked provider coverage for fallback and procurement flexibility.
  • Claude Opus 4.8 uniquely exposes Vision, Multimodal, and Reasoning in local model data.
  • Local decision data tags Claude Opus 4.8 for Coding, RAG, and Agents.
Choose Mistral Magistral Small 2509 when...
  • Mistral Magistral Small 2509 has the lower cheapest tracked output price at $1.50/1M tokens.

Monthly cost at traffic

Estimate token spend from the cheapest tracked input and output route or tier on this page.

Lower estimate Mistral Magistral Small 2509

Claude Opus 4.8

$10,250

Cheapest tracked route/tier: Anthropic

Mistral Magistral Small 2509

$775

Cheapest tracked route/tier: AWS Bedrock

Estimated monthly gap: $9,475. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.

Switch friction

Claude Opus 4.8 -> Mistral Magistral Small 2509
  • Provider overlap exists on AWS Bedrock and Vercel AI Gateway; start route-level A/B tests there.
  • Mistral Magistral Small 2509 is $23.50/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
  • Check replacement coverage for Vision, Multimodal, and Reasoning before moving production traffic.
Mistral Magistral Small 2509 -> Claude Opus 4.8
  • Provider overlap exists on AWS Bedrock and Vercel AI Gateway; start route-level A/B tests there.
  • Claude Opus 4.8 is $23.50/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
  • Claude Opus 4.8 adds Vision, Multimodal, and Reasoning in local capability data.

Specs

Specification
Released2026-05-282025-09-01
Context window1m
Parameters24B
Architecturedecoder only-
LicenseProprietaryProprietary
Knowledge cutoff2026-01-

Pricing and availability

Pricing attributeClaude Opus 4.8Mistral Magistral Small 2509
Input price$5/1M tokens$0.50/1M tokens
Output price$25/1M tokens$1.50/1M tokens
Providers

Capabilities

CapabilityClaude Opus 4.8Mistral Magistral Small 2509
VisionYesNo
MultimodalYesNo
ReasoningYesNo
Function callingYesNo
Tool useYesNo
Structured outputsYesNo
Code executionYesNo
IDE integrationNoNo
Computer useYesNo
Parallel agentsYesNo

Benchmarks

No shared benchmark rows are currently sourced for this pair.

Deep dive

The capability footprint differs most on vision: Claude Opus 4.8, multimodal input: Claude Opus 4.8, reasoning mode: Claude Opus 4.8, function calling: Claude Opus 4.8, tool use: Claude Opus 4.8, structured outputs: Claude Opus 4.8, and code execution: Claude Opus 4.8. Both models share the core language-model surface, 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, Claude Opus 4.8 lists $5/1M input and $25/1M output tokens on the cheapest tracked provider, while Mistral Magistral Small 2509 lists $0.50/1M input and $1.50/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts Mistral Magistral Small 2509 lower by about $10.20 per million blended tokens. Availability is 7 providers versus 2, so concentration risk also matters.

Choose Claude Opus 4.8 when coding workflow support and broader provider choice are central to the workload. Choose Mistral Magistral Small 2509 when provider fit and lower input-token cost are more important. For production, rerun your own prompts through the exact provider, region, and tool stack you plan to ship.

FAQ

Which is cheaper, Claude Opus 4.8 or Mistral Magistral Small 2509?

Mistral Magistral Small 2509 is cheaper on tracked token pricing. Claude Opus 4.8 costs $5/1M input and $25/1M output tokens. Mistral Magistral Small 2509 costs $0.50/1M input and $1.50/1M output tokens. Provider discounts or batch pricing can still change the final bill.

Is Claude Opus 4.8 or Mistral Magistral Small 2509 open source?

Claude Opus 4.8 is listed under Proprietary. Mistral Magistral Small 2509 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, Claude Opus 4.8 or Mistral Magistral Small 2509?

Claude Opus 4.8 has the clearer documented vision signal in this comparison. If vision is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.

Which is better for multimodal input, Claude Opus 4.8 or Mistral Magistral Small 2509?

Claude Opus 4.8 has the clearer documented multimodal input signal in this comparison. If multimodal input is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.

Which is better for reasoning mode, Claude Opus 4.8 or Mistral Magistral Small 2509?

Claude Opus 4.8 has the clearer documented reasoning mode signal in this comparison. If reasoning mode is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.

Where can I run Claude Opus 4.8 and Mistral Magistral Small 2509?

Claude Opus 4.8 is available on Anthropic, AWS Bedrock, GCP Vertex AI, Microsoft Foundry, and OpenRouter. Mistral Magistral Small 2509 is available on AWS Bedrock and Vercel AI Gateway. Provider coverage can affect latency, region availability, compliance posture, and fallback options.

Continue comparing

Last reviewed: 2026-05-28. Data sourced from public model cards and provider documentation.