Claude Opus 4.5 vs Phi 3.5 MoE Instruct
Claude Opus 4.5 (2025) and Phi 3.5 MoE Instruct (2024) are frontier reasoning models from Anthropic and Microsoft Research. Claude Opus 4.5 ships a 200k-token context window, while Phi 3.5 MoE Instruct ships a 128k-token context window. On pricing, Phi 3.5 MoE Instruct costs $0.50/1M input tokens versus $5/1M 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.
Phi 3.5 MoE Instruct is ~900% cheaper at $0.50/1M; pay for Claude Opus 4.5 only for coding workflow support.
Decision scorecard
Local evidence first| Signal | Claude Opus 4.5 | Phi 3.5 MoE Instruct |
|---|---|---|
| Best for | reasoning-heavy apps, multimodal apps, and tool-calling agents | general production evaluation |
| Decision fit | Coding, RAG, and Agents | Long context |
| Context window | 200k | 128k |
| Cheapest output | $25/1M tokens | $0.50/1M tokens |
| Provider routes | 6 tracked | 1 tracked |
| Shared benchmarks | 0 shared | 0 shared |
Decision tradeoffs
- Claude Opus 4.5 has the larger context window for long prompts, retrieval packs, or transcript analysis.
- Claude Opus 4.5 has broader tracked provider coverage for fallback and route flexibility.
- Claude Opus 4.5 uniquely exposes Vision, Multimodal, and Reasoning in local model data.
- Local decision data tags Claude Opus 4.5 for Coding, RAG, and Agents.
- Phi 3.5 MoE Instruct has the lower cheapest tracked output price at $0.50/1M tokens.
- Local decision data tags Phi 3.5 MoE Instruct for Long context.
Monthly cost at traffic
Estimate token spend from the cheapest tracked input and output route or tier on this page.
Claude Opus 4.5
$10,250
Cheapest tracked route/tier: Microsoft Foundry
Phi 3.5 MoE Instruct
$525
Cheapest tracked route/tier: Fireworks AI
Estimated monthly gap: $9,725. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.
Switch friction
- No overlapping tracked provider route is sourced for Claude Opus 4.5 and Phi 3.5 MoE Instruct; plan for SDK, billing, or endpoint changes.
- Phi 3.5 MoE Instruct is $24.50/1M 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.
- No overlapping tracked provider route is sourced for Phi 3.5 MoE Instruct and Claude Opus 4.5; plan for SDK, billing, or endpoint changes.
- Claude Opus 4.5 is $24.50/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
- Claude Opus 4.5 adds Vision, Multimodal, and Reasoning in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2025-11-01 | 2024-08-20 |
| Context window | 200k | 128k |
| Parameters | — | 16x3.8B (42B, 6.6B active) |
| Architecture | Decoder Only | Decoder Only |
| License | Proprietary | MITOSI-approved |
| Openness | Proprietary | Open source |
| Weights | Not released | Unknown |
| Code | Unknown | Unknown |
| Commercial use | Commercial use: conditional | Commercial use: permitted |
| Knowledge cutoff | 2025-12 | 2023-10 |
Pricing and availability
| Pricing attribute | Claude Opus 4.5 | Phi 3.5 MoE Instruct |
|---|---|---|
| Input price | $5/1M tokens | $0.50/1M tokens |
| Output price | $25/1M tokens | $0.50/1M tokens |
| Providers |
Capabilities
| Capability | Claude Opus 4.5 | Phi 3.5 MoE Instruct |
|---|---|---|
| Vision | Yes | No |
| Multimodal | Yes | No |
| Reasoning | Yes | No |
| JSON / Tool use | Yes | No |
| Structured outputs | Yes | No |
| Code execution | Yes | No |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
No shared benchmark scores are currently available for this pair.
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Last reviewed: 2026-07-26. Data sourced from public model cards and provider documentation.