Phi-3.5 Medium vs Sonar Pro
A complete head-to-head: pricing, context window, benchmarks, modality coverage, and openness, with a programmatic verdict synthesized from the underlying data.
Updated
Phi-3.5 Medium specs · Sonar Pro specs- PriceSonar Pro
Sonar Pro publishes pricing ($15.00 / 1M output tokens) while Phi-3.5 Medium does not.
- Context windowSonar Pro
Sonar Pro accepts 200K tokens vs 128K, 1.6× the room for long documents and codebases.
- BenchmarksTie
No directly comparable public benchmarks are available for both models, check the spec sheets for individual scores.
- ModalitiesTie
Both handle text.
- OpennessPhi-3.5 Medium
Phi-3.5 Medium ships open weights (MIT); Sonar Pro is API-only.
On balance Sonar Pro edges ahead, winning 2 of 5 categories against Phi-3.5 Medium's 1. Sonar Pro publishes pricing ($15.00 / 1M output tokens) while Phi-3.5 Medium does not. Sonar Pro accepts 200K tokens vs 128K, 1.6× the room for long documents and codebases.
No directly comparable public benchmarks are available for both models, check the spec sheets for individual scores. Both target the same set of modalities (text), so the deciding factors are price, context, and raw quality. Phi-3.5 Medium ships open weights (MIT); Sonar Pro is API-only.
Sonar Pro is the newer of the two, released 5 months after Phi-3.5 Medium, which usually means a more recent knowledge cutoff and updated safety post-training. Phi-3.5 Medium is usually picked for on device and edge deployment workloads, while Sonar Pro sees more deployments in research agent and rag. If pricing matters more than every last benchmark point, run the numbers in the calculator below before committing.
Side-by-side specs
| Spec | Phi-3.5 Medium | Sonar Pro |
|---|---|---|
| Provider | Microsoft | Perplexity |
| Released | Aug 2024 | Jan 2025 |
| Modalities | text | text |
| Context window | 128K tokens | 200K tokens |
| Max output | , | , |
| Input · 1M | Pricing not published | $3.00 / 1M tokens |
| Output · 1M | Pricing not published | $15.00 / 1M tokens |
| Knowledge cutoff | , | , |
| Open weights | Yes (MIT) | No |
| API available | Yes | Yes |
Pricing at scale
What you'd actually pay at typical workloads. Numbers come from each model's published per-million-token rates.
- Light usage, 100k in / 50k out per day, vs $31.50
- Heavy usage, 1M in / 500k out per day, vs $315
- RAG workload, 5M in / 200k out per day, vs $540
Light usage, 100k in / 50k out per day: pricing not directly comparable (one or both models are missing public per-token rates). Heavy usage, 1M in / 500k out per day: pricing not directly comparable (one or both models are missing public per-token rates). RAG workload, 5M in / 200k out per day: pricing not directly comparable (one or both models are missing public per-token rates).
Estimated spend for the listed models at your usage. Numbers are derived from each model's published per-million-token rates.
- Phi-3.5 MediumPricing unavailable
- Sonar Pro$1.05
Benchmarks compared
Only sourced numbers. Where a benchmark is missing for one model we show the available value rather than fabricating the other.
- MMLU78.9
Phi-3.5 Medium fits when…
- MIT license
- 128k context
- Strong reasoning at 14B
- Self-hosting and on-prem requirements, open weights (MIT).
Sonar Pro fits when…
- Multi-step web search
- Deep research output
- Citations
- Long-context tasks, handles 200K tokens vs 128K for Phi-3.5 Medium.
Consider Phi-4
Microsoft's 14B model, exceptional quality-per-parameter via curated synthetic training data.
Frequently asked
Is Phi-3.5 Medium or Sonar Pro cheaper?
Per-token pricing isn't published for at least one of these models, check each model's spec page for current rates.Which has the larger context window?
Sonar Pro accepts 200K tokens vs 128K for Phi-3.5 Medium.Is Phi-3.5 Medium or Sonar Pro better for coding?
Both Phi-3.5 Medium and Sonar Pro are competitive on coding benchmarks. See each model's individual spec page for HumanEval and SWE-bench scores where published. For an opinionated pick, consult our Best LLM for Coding ranking.Are either of these models open source?
Phi-3.5 Medium ships open weights (MIT). Sonar Pro is API-only.When were Phi-3.5 Medium and Sonar Pro released?
Phi-3.5 Medium was released by Microsoft on 2024-08-20. Sonar Pro was released by Perplexity on 2025-01-21.
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