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Claude Opus 4.6 vs Phi 3.5 Mini Instruct

Claude Opus 4.6 (2026) and Phi 3.5 Mini Instruct (2024) are frontier reasoning models from Anthropic and Microsoft Research. Claude Opus 4.6 ships a 1M-token context window, while Phi 3.5 Mini Instruct ships a 128K-token context window. On pricing, Phi 3.5 Mini Instruct costs $0.9/1M input tokens versus $5/1M for the alternative. This comparison covers specs, pricing, capabilities, benchmarks, provider availability, and production fit.

Phi 3.5 Mini Instruct is ~456% cheaper at $0.9/1M; pay for Claude Opus 4.6 only for coding workflow support.

Specs

Released2026-02-052024-08-20
Context window1M128K
Parameters3.8B
Architecturedecoder onlydecoder only
LicenseProprietaryMIT
Knowledge cutoff2025-12-

Pricing and availability

Claude Opus 4.6Phi 3.5 Mini Instruct
Input price$5/1M tokens$0.9/1M tokens
Output price$25/1M tokens$0.9/1M tokens
Providers

Capabilities

Claude Opus 4.6Phi 3.5 Mini Instruct
Vision
Multimodal
Reasoning
Function calling
Tool use
Structured outputs
Code execution

Benchmarks

No shared benchmark rows are currently sourced for this pair.

Deep dive

The capability footprint differs most on vision: Claude Opus 4.6, multimodal input: Claude Opus 4.6, reasoning mode: Claude Opus 4.6, function calling: Claude Opus 4.6, tool use: Claude Opus 4.6, structured outputs: Claude Opus 4.6, and code execution: Claude Opus 4.6. 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 4.6 lists $5/1M input and $25/1M output tokens, while Phi 3.5 Mini Instruct lists $0.9/1M input and $0.9/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts Phi 3.5 Mini Instruct lower by about $10.10 per million blended tokens. Availability is 4 providers versus 2, so concentration risk also matters.

Choose Claude Opus 4.6 when coding workflow support, larger context windows, and broader provider choice are central to the workload. Choose Phi 3.5 Mini Instruct 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 has a larger context window, Claude Opus 4.6 or Phi 3.5 Mini Instruct?

Claude Opus 4.6 supports 1M tokens, while Phi 3.5 Mini 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, Claude Opus 4.6 or Phi 3.5 Mini Instruct?

Phi 3.5 Mini Instruct is cheaper on tracked token pricing. Claude Opus 4.6 costs $5/1M input and $25/1M output tokens. Phi 3.5 Mini Instruct costs $0.9/1M input and $0.9/1M output tokens. Provider discounts or batch pricing can still change the final bill.

Is Claude Opus 4.6 or Phi 3.5 Mini Instruct open source?

Claude Opus 4.6 is listed under Proprietary. Phi 3.5 Mini Instruct is listed under MIT. 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 4.6 or Phi 3.5 Mini Instruct?

Claude Opus 4.6 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 4.6 or Phi 3.5 Mini Instruct?

Claude Opus 4.6 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.

Where can I run Claude Opus 4.6 and Phi 3.5 Mini Instruct?

Claude Opus 4.6 is available on OpenRouter, Anthropic, AWS Bedrock, and GCP Vertex AI. Phi 3.5 Mini Instruct is available on Fireworks AI and NVIDIA NIM. Provider coverage can affect latency, region availability, compliance posture, and fallback options.

Continue comparing

Last reviewed: 2026-04-24. Data sourced from public model cards and provider documentation.