Mixtral 8x7B vs Phi 3.5 Mini Instruct
Mixtral 8x7B (2023) and Phi 3.5 Mini Instruct (2024) are compact production models from MistralAI and Microsoft Research. Mixtral 8x7B ships a 32k-token context window, while Phi 3.5 Mini Instruct ships a 128k-token context window. On pricing, Mixtral 8x7B costs $0.15/1M input tokens versus $0.90/1M 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.
Mixtral 8x7B is ~500% cheaper at $0.15/1M; pay for Phi 3.5 Mini Instruct only for long-context analysis.
Decision scorecard
Local evidence first| Signal | Mixtral 8x7B | Phi 3.5 Mini Instruct |
|---|---|---|
| Best for | provider-routed production | provider-routed production |
| Decision fit | Coding and Classification | Long context |
| Context window | 32k | 128k |
| Cheapest output | $0.45/1M tokens | $0.90/1M tokens |
| Provider routes | 18 tracked | 2 tracked |
| Shared benchmarks | 0 rows | 0 rows |
Decision tradeoffs
- Mixtral 8x7B has the lower cheapest tracked output price at $0.45/1M tokens.
- Mixtral 8x7B has broader tracked provider coverage for fallback and procurement flexibility.
- Local decision data tags Mixtral 8x7B for Coding and Classification.
- Phi 3.5 Mini Instruct has the larger context window for long prompts, retrieval packs, or transcript analysis.
- Local decision data tags Phi 3.5 Mini Instruct for Long context.
Monthly cost at traffic
Estimate token spend from the cheapest tracked input and output route or tier on this page.
Mixtral 8x7B
$233
Cheapest tracked route/tier: Mistral AI Studio
Phi 3.5 Mini Instruct
$945
Cheapest tracked route/tier: Fireworks AI
Estimated monthly gap: $713. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.
Switch friction
- Provider overlap exists on Fireworks AI and NVIDIA NIM; start route-level A/B tests there.
- Phi 3.5 Mini Instruct is $0.45/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
- Provider overlap exists on NVIDIA NIM and Fireworks AI; start route-level A/B tests there.
- Mixtral 8x7B is $0.45/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
Specs
| Specification | ||
|---|---|---|
| Released | 2023-12-11 | 2024-08-20 |
| Context window | 32k | 128k |
| Parameters | 8x7B | 3.8B |
| Architecture | mixture of experts | decoder only |
| License | Apache 2.0(OSI) | MIT(OSI) |
| Openness | Open source | Open source |
| Commercial use | Commercial use allowed | Commercial use allowed |
| Knowledge cutoff | 2023-12 | 2023-10 |
Pricing and availability
| Pricing attribute | Mixtral 8x7B | Phi 3.5 Mini Instruct |
|---|---|---|
| Input price | $0.15/1M tokens | $0.90/1M tokens |
| Output price | $0.45/1M tokens | $0.90/1M tokens |
| Providers |
Capabilities
| Capability | Mixtral 8x7B | Phi 3.5 Mini Instruct |
|---|---|---|
| Vision | No | No |
| Multimodal | No | No |
| Reasoning | No | No |
| Function calling | No | No |
| Tool use | No | No |
| Structured outputs | No | No |
| Code execution | No | No |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
No shared benchmark rows are currently sourced for this pair.
Deep dive
The capability footprint is close: both models cover the core production surface. That makes context budget, benchmark fit, and provider maturity more important than a simple checklist. If your application depends on one integration detail, verify it against the provider route you plan to use, not just the base model listing.
For cost, Mixtral 8x7B lists $0.15/1M input and $0.45/1M output tokens on the cheapest tracked provider, while Phi 3.5 Mini Instruct lists $0.90/1M input and $0.90/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts Mixtral 8x7B lower by about $0.66 per million blended tokens. Availability is 18 providers versus 2, so concentration risk also matters.
Choose Mixtral 8x7B when provider fit, lower input-token cost, and broader provider choice are central to the workload. Choose Phi 3.5 Mini Instruct when long-context analysis 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. This keeps the decision grounded in measurable tradeoffs instead of brand-level assumptions. It also helps separate model capability from provider packaging, which can change cost and latency.
FAQ
Which has a larger context window, Mixtral 8x7B or Phi 3.5 Mini Instruct?
Phi 3.5 Mini Instruct supports 128k tokens, while Mixtral 8x7B supports 32k tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible.
Which is cheaper, Mixtral 8x7B or Phi 3.5 Mini Instruct?
Mixtral 8x7B is cheaper on tracked token pricing. Mixtral 8x7B costs $0.15/1M input and $0.45/1M output tokens. Phi 3.5 Mini Instruct costs $0.90/1M input and $0.90/1M output tokens. Provider discounts or batch pricing can still change the final bill.
Is Mixtral 8x7B or Phi 3.5 Mini Instruct open source?
Mixtral 8x7B is listed under Apache 2.0. 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.
Where can I run Mixtral 8x7B and Phi 3.5 Mini Instruct?
Mixtral 8x7B is available on Databricks Foundation Model Serving, NVIDIA NIM, GCP Vertex AI, AWS Bedrock, and OctoAI API (Deprecated). 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.
When should I pick Mixtral 8x7B over Phi 3.5 Mini Instruct?
Mixtral 8x7B is ~500% cheaper at $0.15/1M; pay for Phi 3.5 Mini Instruct only for long-context analysis. If your workload also depends on provider fit, start with Mixtral 8x7B; if it depends on long-context analysis, run the same evaluation with Phi 3.5 Mini Instruct.
Continue comparing
Last reviewed: 2026-05-19. Data sourced from public model cards and provider documentation.