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Llama 4 405B 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

Llama 4 405B specs · Phi-3.5 Medium specs
Verdict by category
  • PriceTie

    Neither model publishes per-token API pricing.

  • Context windowLlama 4 405B

    Llama 4 405B accepts 256K tokens vs 128K, 2.0× 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.

  • ModalitiesLlama 4 405B

    Llama 4 405B supports 2 modalities (text, vision) vs 1 for Phi-3.5 Medium.

  • OpennessTie

    Both ship open weights, self-host either one.

On balance Llama 4 405B edges ahead, winning 2 of 5 categories against Phi-3.5 Medium's 0. Neither model publishes per-token API pricing. Llama 4 405B accepts 256K tokens vs 128K, 2.0× the room for long documents and codebases.

No directly comparable public benchmarks are available for both models, check the spec sheets for individual scores. They differ in modality coverage, Llama 4 405B handles text, vision while Phi-3.5 Medium handles text, which can be the deciding factor before you even look at benchmarks. Both ship open weights, self-host either one.

Llama 4 405B is the newer of the two, released 8 months after Phi-3.5 Medium, which usually means a more recent knowledge cutoff and updated safety post-training. Llama 4 405B is usually picked for open source llm and fine tuning 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

SpecLlama 4 405BPhi-3.5 Medium
ProviderMetaMicrosoft
ReleasedApr 2025Aug 2024
Modalitiestext, visiontext
Context window256K tokens128K tokens
Max output,,
Input · 1MPricing not publishedPricing not published
Output · 1MPricing not publishedPricing not published
Knowledge cutoff2024-12,
Open weightsYes (Llama 4 Community License)Yes (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.

  • Llama 4 405BPricing 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.

Llama 4 405BPhi-3.5 Medium
  • MMLU,78.9
Pick Llama 4 405B if

Llama 4 405B fits when…

  • Strongest open-weight model at launch
  • Multimodal (text + vision)
  • Wide hosting availability
  • Long-context tasks, handles 256K tokens vs 128K for Phi-3.5 Medium.
  • Multimodal needs covering vision.
Pick Phi-3.5 Medium if

Phi-3.5 Medium fits when…

  • MIT license
  • 128k context
  • Strong reasoning at 14B
Don't want either?

Consider Llama 4 70B

Meta's mid-tier Llama 4, the practical workhorse for self-hosted deployments.

See Llama 4 70B specsLlama 4 405B vs Llama 4 70BPhi-3.5 Medium vs Llama 4 70B

Frequently asked

  • Is Llama 4 405B 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?
    Llama 4 405B accepts 256K tokens vs 128K for Phi-3.5 Medium.
  • Is Llama 4 405B or Phi-3.5 Medium better for coding?
    Both Llama 4 405B 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?
    Both ship with open weights. Llama 4 405B is licensed under Llama 4 Community License; Phi-3.5 Medium under MIT.
  • When were Llama 4 405B and Phi-3.5 Medium released?
    Llama 4 405B was released by Meta on 2025-04-05. Phi-3.5 Medium was released by Microsoft on 2024-08-20.
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