ZMIME
Comparison · 3 models · Updated Oct 4, 2026

o3 vs GPT-5.4 mini vs Gemini 2.5 Pro

Too close to call on our weighted score (Gemini 2.5 Pro 63, GPT-5.4 mini 63, o3 58). The right pick depends on what you value most.

  1. OpenAI

    o3

    Released Apr 16, 2025

    58/100
    • ECI146.9
    • Price$2.00 / $8.00
    • Context200K
  2. OpenAI

    GPT-5.4 mini

    Released Mar 17, 2026

    63/100
    • ECI148.8
    • Price$0.75 / $4.50
    • Context400K
  3. Google

    Gemini 2.5 Pro

    Released Jun 17, 2025

    63/100
    • ECI145.3
    • Price$1.25 / $10.00
    • Context1.05M
01 — Verdict

Too close to call

It is close. Our weighted score puts them within a point (Gemini 2.5 Pro 63/100, GPT-5.4 mini 63/100, o3 58/100), so choose by what matters most for your work: GPT-5.4 mini for raw capability and Gemini 2.5 Pro for long inputs. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

  • CapabilityGPT-5.4 miniCapabilities Index (ECI): GPT-5.4 mini 148.8 · o3 146.9 · Gemini 2.5 Pro 145.3
  • Lowest priceGPT-5.4 miniGPT-5.4 mini $1.69 · Gemini 2.5 Pro $3.44 · o3 $3.50 per 1M tokens (3:1 blend)
  • Longest contextGemini 2.5 ProGemini 2.5 Pro 1,048,576 · GPT-5.4 mini 400,000 · o3 200,000 tokens
  • Widest inputsGemini 2.5 Proo3: Text, Images, PDFs · GPT-5.4 mini: Text, Images · Gemini 2.5 Pro: Text, Images, PDFs, Audio, Video
  • Self-hostingNo open weightsAll three are available only through APIs
How the score is built
MeasureWeighto3GPT-5.4 miniGemini 2.5 Pro
CapabilityCapabilities Index (ECI)50%747772
Price25%243924
Inputs & features15%8070100
Context window10%324461
Overall100%58/10063/10063/100
02 — Side by side

Every spec in one table

Highlighted cells lead their row. Dashes mean the data is not published.

o3 vs GPT-5.4 mini vs Gemini 2.5 Pro specifications side by side
Specificationo3OpenAIGPT-5.4 miniOpenAIGemini 2.5 ProGoogle
Capability
Capabilities Index (ECI)146.9148.8 (best)145.3
ECI rank#63 of 148#56 of 148 (best)#78 of 148
GPQA DiamondGraduate-level science questions81.8%86.9% (best)85.3%
FrontierMath Tiers 1–3Research-level mathematics33.3%51.2% (best)24.6%
OTIS Mock AIME 2024–2025Competition mathematics84.4%88.9% (best)84.7%
SWE-bench VerifiedFixing real GitHub issues62.3% (best)—57.6%
SimpleQA VerifiedShort factual questions49.4% (best)29.4%—
Price per million tokens
Input$2.00$0.75 (best)$1.25
Output$8.00$4.50 (best)$10.00
Cached input$0.50$0.075 (best)$0.125
Blended (3:1)$3.50$1.69 (best)$3.44
Long-context rateSame rateSame rateOver 200K: $2.50 / $15.00
Price sourceOfficial OpenAI APIOfficial OpenAI APIOfficial Google API
Limits
Context window200,000 tokens400,000 tokens1,048,576 tokens (best)
Max output100,000 tokens128,000 tokens (best)65,536 tokens
Inputs and features
TextYesYesYes
ImagesYesYesYes
PDFsYesNoYes
AudioNoNoYes
VideoNoNoYes
ReasoningYeslow · medium · highYeslow · medium · high · xhighYes
Tool callingYesYesYes
Structured outputYesYesYes
Availability
WeightsProprietaryProprietaryProprietary
API model IDo3gpt-5.4-minigemini-2.5-pro
API providers1829 (best)22
ReleasedApr 16, 2025Mar 17, 2026Jun 17, 2025
Knowledge cutoffMay 2024Aug 31, 2025Jan 2025
03 — Cost

What would a month cost?

Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.

  • o3$36.00
  • GPT-5.4 mini$16.50
  • Gemini 2.5 Pro$32.50
04 — Questions

Which should you choose?

Which is better: o3, GPT-5.4 mini or Gemini 2.5 Pro?

It is close. Our weighted score puts them within a point (Gemini 2.5 Pro 63/100, GPT-5.4 mini 63/100, o3 58/100), so choose by what matters most for your work: GPT-5.4 mini for raw capability and Gemini 2.5 Pro for long inputs. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

Which is cheaper, o3, GPT-5.4 mini or Gemini 2.5 Pro?

GPT-5.4 mini is cheaper at $0.75 input / $4.50 output per million tokens (official OpenAI API price). Gemini 2.5 Pro costs $1.25 input / $10.00 output per million tokens (official Google API price); o3 costs $2.00 input / $8.00 output per million tokens (official OpenAI API price). At a typical mix of three input tokens to one output token, that is $1.69 per million tokens for GPT-5.4 mini versus $3.44 for Gemini 2.5 Pro (2× as much) and $3.50 for o3 (2.1× as much).

Which scores higher on benchmarks?

GPT-5.4 mini scores higher on the Capabilities Index (ECI): GPT-5.4 mini 148.8 (#56 of 148), o3 146.9 (#63 of 148) and Gemini 2.5 Pro 145.3 (#78 of 148). The confidence ranges of the top two overlap (147.1–150.5 vs 144.9–148.6), so treat the gap as small. On individual benchmarks: GPQA Diamond — GPT-5.4 mini 86.9%, Gemini 2.5 Pro 85.3%, o3 81.8%; FrontierMath Tiers 1–3 — GPT-5.4 mini 51.2%, o3 33.3%, Gemini 2.5 Pro 24.6%; OTIS Mock AIME 2024–2025 — GPT-5.4 mini 88.9%, Gemini 2.5 Pro 84.7%, o3 84.4%.

Which is better for coding?

There are no published SWE-bench Verified results for GPT-5.4 mini yet, so there is no like-for-like coding score. On overall capability, GPT-5.4 mini leads, which tends to carry over to coding, but test on your own codebase. All three support tool calling for agent workflows.

Which has the bigger context window?

Gemini 2.5 Pro has the largest context window at 1,048,576 tokens, against 400,000 for GPT-5.4 mini and 200,000 for o3. Maximum output per response: o3 up to 100,000, GPT-5.4 mini up to 128,000, Gemini 2.5 Pro up to 65,536 tokens.

Which can read images, PDFs, audio or video?

o3 accepts text, images and PDFs; GPT-5.4 mini accepts text and images; Gemini 2.5 Pro accepts text, images, PDFs, audio and video. Gemini 2.5 Pro handles the widest range of inputs.

Are any of these open source?

No. o3, GPT-5.4 mini and Gemini 2.5 Pro are proprietary and only available through APIs and apps.

Which is newer?

GPT-5.4 mini is the newest, released Mar 17, 2026. Gemini 2.5 Pro came out Jun 17, 2025; o3 came out Apr 16, 2025. Knowledge cutoff: o3 May 2024, GPT-5.4 mini Aug 31, 2025, Gemini 2.5 Pro Jan 2025.

How do you decide the winner?

Each model gets a 0–100 score on capability (50%, independent benchmark results); price (25%, blended price per million tokens (3 input : 1 output), log scale); inputs & features (15%, image, PDF, audio and video input, tool calling, structured output and reasoning); context window (10%, maximum tokens per request, log scale). Dimensions missing for any model are dropped and the remaining weights rescaled, so every model is judged on the same evidence. Specs and prices come from public model listings and the labs’ own API pages; capability scores come from independent benchmark runs. Data updated Oct 4, 2026.