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Grok 2 vs Phi-3.5 Medium

A complete head-to-head: pricing, context window, benchmarks, modality coverage, and openness, with a programmatic verdict synthesized from the underlying data.

Updated

Grok 2 specs · Phi-3.5 Medium specs
Verdict by category
  • PriceTie

    Neither model publishes per-token API pricing.

  • Context windowTie

    Both ship a 128K-token context window.

  • BenchmarksTie

    No directly comparable public benchmarks are available for both models, check the spec sheets for individual scores.

  • ModalitiesGrok 2

    Grok 2 supports 2 modalities (text, vision) vs 1 for Phi-3.5 Medium.

  • OpennessPhi-3.5 Medium

    Phi-3.5 Medium ships open weights (MIT); Grok 2 is API-only.

It's a genuine coin-flip between Grok 2 and Phi-3.5 Medium: 1 category wins each, with the rest tied. Neither model publishes per-token API pricing. Both ship a 128K-token context window.

No directly comparable public benchmarks are available for both models, check the spec sheets for individual scores. They differ in modality coverage, Grok 2 handles text, vision while Phi-3.5 Medium handles text, which can be the deciding factor before you even look at benchmarks. Phi-3.5 Medium ships open weights (MIT); Grok 2 is API-only.

Both shipped within roughly a month of each other in 2024, so they share the same generation of training data and tooling. Grok 2 is usually picked for chatbots workloads, while Phi-3.5 Medium sees more deployments in on device and edge deployment. If pricing matters more than every last benchmark point, run the numbers in the calculator below before committing.

Side-by-side specs

SpecGrok 2Phi-3.5 Medium
ProviderxAIMicrosoft
ReleasedAug 2024Aug 2024
Modalitiestext, visiontext
Context window128K tokens128K tokens
Max output,,
Input · 1MPricing not publishedPricing not published
Output · 1MPricing not publishedPricing not published
Knowledge cutoff,,
Open weightsNoYes (MIT)
API availableYesYes

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 ,
  • Heavy usage, 1M in / 500k out per day, vs ,
  • RAG workload, 5M in / 200k out per day, vs ,

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).

Price calculator

Estimated spend for the listed models at your usage. Numbers are derived from each model's published per-million-token rates.

  • Grok 2Pricing unavailable
  • Phi-3.5 MediumPricing unavailable

Benchmarks compared

Only sourced numbers. Where a benchmark is missing for one model we show the available value rather than fabricating the other.

Grok 2Phi-3.5 Medium
  • MMLU,78.9
Pick Grok 2 if

Grok 2 fits when…

  • Free on X Premium
  • Real-time data
  • Multimodal needs covering vision.
Pick Phi-3.5 Medium if

Phi-3.5 Medium fits when…

  • MIT license
  • 128k context
  • Strong reasoning at 14B
  • Self-hosting and on-prem requirements, open weights (MIT).
Don't want either?

Consider Grok 4

xAI's mid-2025 flagship, top scores on Humanity's Last Exam at launch, with native real-time X integration.

See Grok 4 specsGrok 2 vs Grok 4Phi-3.5 Medium vs Grok 4

Frequently asked

  • Is Grok 2 or Phi-3.5 Medium 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?
    Both Grok 2 and Phi-3.5 Medium ship a 128K-token context window.
  • Is Grok 2 or Phi-3.5 Medium better for coding?
    Both Grok 2 and Phi-3.5 Medium 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). Grok 2 is API-only.
  • When were Grok 2 and Phi-3.5 Medium released?
    Grok 2 was released by xAI on 2024-08-13. Phi-3.5 Medium was released by Microsoft on 2024-08-20.
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