LLM·Dex
Newsletter

Gemini 3 Pro vs GPT-5 nano

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 nano specs
Verdict by category
  • PriceGPT-5 nano

    GPT-5 nano publishes pricing ($0.40 / 1M output tokens) while Gemini 3 Pro does not.

  • 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 2 for GPT-5 nano.

  • OpennessTie

    Both are closed-weight, API-only.

On balance Gemini 3 Pro edges ahead, winning 2 of 5 categories against GPT-5 nano's 1. GPT-5 nano publishes pricing ($0.40 / 1M output tokens) while Gemini 3 Pro does not. 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 nano handles text, vision, which can be the deciding factor before you even look at benchmarks. Both are closed-weight, API-only.

Gemini 3 Pro is the newer of the two, released 4 months after GPT-5 nano, 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 nano sees more deployments in cheapest llm and fastest llm. 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 nano
ProviderGoogleOpenAI
ReleasedDec 2025Aug 2025
Modalitiestext, vision, audio, videotext, vision
Context window1.0M tokens400K tokens
Max output65.5K tokens128K tokens
Input · 1MPricing not published$0.050 / 1M tokens
Output · 1MPricing not published$0.40 / 1M tokens
Knowledge cutoff2025-012024-09
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 $0.750
  • Heavy usage, 1M in / 500k out per day, vs $7.50
  • RAG workload, 5M in / 200k out per day, vs $9.90

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 nano$0.025

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 nano
  • 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 nano.
  • Multimodal needs covering audio, video.
Pick GPT-5 nano if

GPT-5 nano fits when…

  • Lowest-cost OpenAI model with vision support
  • Fast P99 latency
  • Good enough for routing and classification
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 nano vs Gemini 3 Flash

Frequently asked

  • Is Gemini 3 Pro or GPT-5 nano 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 nano.
  • Is Gemini 3 Pro or GPT-5 nano better for coding?
    Both Gemini 3 Pro and GPT-5 nano 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 nano released?
    Gemini 3 Pro was released by Google on 2025-12-09. GPT-5 nano was released by OpenAI on 2025-08-07.
Friday digest

The week's AI launches, in your inbox.

One short email every Friday, new models, leaks, and quietly-shipped APIs you missed.