LLM·Dex

GPT-5 vs o3-mini

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

Updated

GPT-5 specs · o3-mini specs
Verdict by category
  • Priceo3-mini

    o3-mini is roughly 2.3× cheaper on output tokens ($4.40 vs $10.00 per 1M).

  • Context windowGPT-5

    GPT-5 accepts 400K tokens vs 200K, 2.0× the room for long documents and codebases.

  • BenchmarksGPT-5

    GPT-5 leads in 1 of 1 shared benchmarks; the biggest gap is on GPQA (graduate-level reasoning), where it scores 89.4 vs 79.7.

  • ModalitiesGPT-5

    GPT-5 supports 3 modalities (text, vision, audio) vs 1 for o3-mini.

  • OpennessTie

    Both are closed-weight, API-only.

On balance GPT-5 edges ahead, winning 3 of 5 categories against o3-mini's 1. o3-mini is roughly 2.3× cheaper on output tokens ($4.40 vs $10.00 per 1M). GPT-5 accepts 400K tokens vs 200K, 2.0× the room for long documents and codebases.

GPT-5 leads in 1 of 1 shared benchmarks; the biggest gap is on GPQA (graduate-level reasoning), where it scores 89.4 vs 79.7. They differ in modality coverage, GPT-5 handles text, vision, audio while o3-mini handles text, which can be the deciding factor before you even look at benchmarks. Both are closed-weight, API-only.

GPT-5 is the newer of the two, released 6 months after o3-mini, which usually means a more recent knowledge cutoff and updated safety post-training. GPT-5 is usually picked for coding llm and agents workloads, while o3-mini sees more deployments in reasoning and math. If pricing matters more than every last benchmark point, run the numbers in the calculator below before committing.

Side-by-side specs

SpecGPT-5o3-mini
ProviderOpenAIOpenAI
ReleasedAug 2025Jan 2025
Modalitiestext, vision, audiotext
Context window400K tokens200K tokens
Max output128K tokens,
Input · 1M$1.25 / 1M tokens$1.10 / 1M tokens
Output · 1M$10.00 / 1M tokens$4.40 / 1M tokens
Knowledge cutoff2024-092023-10
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$18.75 vs $9.90
  • Heavy usage, 1M in / 500k out per day$188 vs $99.00
  • RAG workload, 5M in / 200k out per day$248 vs $191

Light usage, 100k in / 50k out per day: $18.75 vs $9.90 per month, model B comes out ahead. Heavy usage, 1M in / 500k out per day: $188 vs $99.00 per month, model B comes out ahead. RAG workload, 5M in / 200k out per day: $248 vs $191 per month, model B comes out ahead.

Price calculator

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

  • GPT-5$0.625
  • o3-mini$0.330

Benchmarks compared

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

GPT-5o3-mini
  • MMLU91.4
  • HumanEval96.2
  • GPQA89.479.7
  • SWE-bench Verified74.9
Pick GPT-5 if

GPT-5 fits when…

  • Unified model, reasoning routed automatically per query
  • Excellent tool-use and JSON-mode discipline
  • Strong agent performance on SWE-bench Verified
  • Long-context tasks, handles 400K tokens vs 200K for o3-mini.
  • Multimodal needs covering vision, audio.
Pick o3-mini if

o3-mini fits when…

  • Reasoning at mid-tier cost
  • Fast for a thinking model
  • Cost-sensitive workloads, 2.3× cheaper than GPT-5 on output tokens.
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.

Frequently asked

  • Is GPT-5 or o3-mini cheaper?
    o3-mini is cheaper at $4.40 / 1M tokens per million output tokens, vs $10.00 / 1M tokens for GPT-5.
  • Which has the larger context window?
    GPT-5 accepts 400K tokens vs 200K for o3-mini.
  • Is GPT-5 or o3-mini better for coding?
    Both GPT-5 and o3-mini 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 GPT-5 and o3-mini released?
    GPT-5 was released by OpenAI on 2025-08-07. o3-mini was released by OpenAI on 2025-01-31.
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