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o3 vs Phi-4

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

Updated

o3 specs · Phi-4 specs
Verdict by category
  • Priceo3

    o3 publishes pricing ($8.00 / 1M output tokens) while Phi-4 does not.

  • Context windowo3

    o3 accepts 200K tokens vs 16K, 12.5× the room for long documents and codebases.

  • Benchmarkso3

    o3 leads in 1 of 1 shared benchmarks; the biggest gap is on HumanEval (Python coding), where it scores 95.0 vs 82.6.

  • Modalitieso3

    o3 supports 2 modalities (text, vision) vs 1 for Phi-4.

  • OpennessPhi-4

    Phi-4 ships open weights (MIT); o3 is API-only.

On balance o3 edges ahead, winning 4 of 5 categories against Phi-4's 1. o3 publishes pricing ($8.00 / 1M output tokens) while Phi-4 does not. o3 accepts 200K tokens vs 16K, 12.5× the room for long documents and codebases.

o3 leads in 1 of 1 shared benchmarks; the biggest gap is on HumanEval (Python coding), where it scores 95.0 vs 82.6. They differ in modality coverage, o3 handles text, vision while Phi-4 handles text, which can be the deciding factor before you even look at benchmarks. Phi-4 ships open weights (MIT); o3 is API-only.

o3 is the newer of the two, released 4 months after Phi-4, which usually means a more recent knowledge cutoff and updated safety post-training. o3 is usually picked for reasoning and math workloads, while Phi-4 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

Speco3Phi-4
ProviderOpenAIMicrosoft
ReleasedApr 2025Dec 2024
Modalitiestext, visiontext
Context window200K tokens16K tokens
Max output,,
Input · 1M$2.00 / 1M tokensPricing not published
Output · 1M$8.00 / 1M tokensPricing not published
Knowledge cutoff2024-06,
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$18.00 vs ,
  • Heavy usage, 1M in / 500k out per day$180 vs ,
  • RAG workload, 5M in / 200k out per day$348 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.

  • o3$0.600
  • Phi-4Pricing unavailable

Benchmarks compared

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

o3Phi-4
  • MMLU,84.8
  • HumanEval95.082.6
  • GPQA87.7
Pick o3 if

o3 fits when…

  • Industry-leading reasoning depth at launch
  • Strong on math, science, and abstract puzzles
  • Tool-use during reasoning loops
  • Long-context tasks, handles 200K tokens vs 16K for Phi-4.
  • Multimodal needs covering vision.
Pick Phi-4 if

Phi-4 fits when…

  • Exceptional quality at 14B parameters
  • MIT license, clean commercial use
  • Strong on math
  • Self-hosting and on-prem requirements, open weights (MIT).
Don't want either?

Consider GPT-5.5

OpenAI's mid-cycle GPT-5 refresh, improved reasoning, tool use, and multimodal grounding over the 2025 launch.

See GPT-5.5 specso3 vs GPT-5.5Phi-4 vs GPT-5.5

Frequently asked

  • Is o3 or Phi-4 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?
    o3 accepts 200K tokens vs 16K for Phi-4.
  • Is o3 or Phi-4 better for coding?
    Both o3 and Phi-4 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-4 ships open weights (MIT). o3 is API-only.
  • When were o3 and Phi-4 released?
    o3 was released by OpenAI on 2025-04-16. Phi-4 was released by Microsoft on 2024-12-12.
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