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Gemini 3 Pro vs GPT-5.5

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

Updated

Gemini 3 Pro specs · GPT-5.5 specs
Verdict by category
  • PriceTie

    Neither model publishes per-token API pricing.

  • Context windowGemini 3 Pro

    Gemini 3 Pro accepts 1.0M tokens vs 400K, 2.6× 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.

  • ModalitiesGemini 3 Pro

    Gemini 3 Pro supports 4 modalities (text, vision, audio, video) vs 3 for GPT-5.5.

  • OpennessTie

    Both are closed-weight, API-only.

On balance Gemini 3 Pro edges ahead, winning 2 of 5 categories against GPT-5.5's 0. Neither model publishes per-token API pricing. Gemini 3 Pro accepts 1.0M tokens vs 400K, 2.6× the room for long documents and codebases.

No directly comparable public benchmarks are available for both models, check the spec sheets for individual scores. They differ in modality coverage, Gemini 3 Pro handles text, vision, audio, video while GPT-5.5 handles text, vision, audio, which can be the deciding factor before you even look at benchmarks. Both are closed-weight, API-only.

GPT-5.5 is the newer of the two, released 3 months after Gemini 3 Pro, which usually means a more recent knowledge cutoff and updated safety post-training. Gemini 3 Pro is usually picked for long context and rag workloads, while GPT-5.5 sees more deployments in agents and tool use. If pricing matters more than every last benchmark point, run the numbers in the calculator below before committing.

Side-by-side specs

SpecGemini 3 ProGPT-5.5
ProviderGoogleOpenAI
ReleasedDec 2025Mar 2026
Modalitiestext, vision, audio, videotext, vision, audio
Context window1.0M tokens400K tokens
Max output65.5K tokens,
Input · 1MPricing not publishedPricing not published
Output · 1MPricing not publishedPricing not published
Knowledge cutoff2025-01,
Open weightsNoNo
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.

  • Gemini 3 ProPricing unavailable
  • GPT-5.5Pricing unavailable

Benchmarks compared

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

Gemini 3 ProGPT-5.5
  • MMLU91.8
  • HumanEval95.4
  • GPQA91.9
Pick Gemini 3 Pro if

Gemini 3 Pro fits when…

  • Massive 1M-token context window
  • State-of-the-art vision and document understanding
  • Strong reasoning at competitive price
  • Long-context tasks, handles 1.0M tokens vs 400K for GPT-5.5.
  • Multimodal needs covering video.
Pick GPT-5.5 if

GPT-5.5 fits when…

  • Industry-leading tool-use and function-calling reliability
  • Strong end-to-end agent performance across SWE-bench and GAIA
  • Wide ecosystem support, ChatGPT, Realtime API, Responses API
Don't want either?

Consider Gemini 3 Flash

Google's high-speed, low-cost mid-tier with the same massive context window, popular for high-volume RAG.

See Gemini 3 Flash specsGemini 3 Pro vs Gemini 3 FlashGPT-5.5 vs Gemini 3 Flash

Frequently asked

  • Is Gemini 3 Pro or GPT-5.5 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?
    Gemini 3 Pro accepts 1.0M tokens vs 400K for GPT-5.5.
  • Is Gemini 3 Pro or GPT-5.5 better for coding?
    Both Gemini 3 Pro and GPT-5.5 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?
    Neither model ships open weights, both are accessible only via their respective providers' APIs.
  • When were Gemini 3 Pro and GPT-5.5 released?
    Gemini 3 Pro was released by Google on 2025-12-09. GPT-5.5 was released by OpenAI on 2026-03-01.
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