ZMIME
Comparison · 3 models · Updated Oct 4, 2026

Gemini 2.5 Pro vs o3 vs o3-mini

Gemini 2.5 Pro comes out ahead, 63 to 58 and 52 on our weighted score, though o3-mini is 44% cheaper per token.

  1. Our pick

    Google

    Gemini 2.5 Pro

    Released Jun 17, 2025

    63/100
    • ECI145.3
    • Price$1.25 / $10.00
    • Context1.05M
  2. OpenAI

    o3

    Released Apr 16, 2025

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

    o3-mini

    Released Jan 31, 2025Deprecated

    52/100
    • ECI140.3
    • Price$1.10 / $4.40
    • Context200K
01 — Verdict

Gemini 2.5 Pro is our pick

Gemini 2.5 Pro is the better all-round choice, scoring 63/100 against o3 (58) and o3-mini (52). It leads on inputs & features and context window. o3 wins on capability. o3-mini wins on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

  • Capabilityo3Capabilities Index (ECI): o3 146.9 · Gemini 2.5 Pro 145.3 · o3-mini 140.3
  • Lowest priceo3-minio3-mini $1.93 · 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 · o3 200,000 · o3-mini 200,000 tokens
  • Widest inputsGemini 2.5 ProGemini 2.5 Pro: Text, Images, PDFs, Audio, Video · o3: Text, Images, PDFs · o3-mini: Text
  • Self-hostingNo open weightsAll three are available only through APIs
How the score is built
MeasureWeightGemini 2.5 Proo3o3-mini
CapabilityCapabilities Index (ECI)50%727466
Price25%242436
Inputs & features15%1008045
Context window10%613232
Overall100%63/10058/10052/100
02 — Side by side

Every spec in one table

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

Gemini 2.5 Pro vs o3 vs o3-mini specifications side by side
SpecificationGemini 2.5 ProGoogleo3OpenAIo3-miniOpenAI
Capability
Capabilities Index (ECI)145.3146.9 (best)140.3
ECI rank#78 of 148#63 of 148 (best)#98 of 148
GPQA DiamondGraduate-level science questions85.3% (best)81.8%77.0%
FrontierMath Tiers 1–3Research-level mathematics24.6%33.3% (best)18.6%
OTIS Mock AIME 2024–2025Competition mathematics84.7% (best)84.4%76.9%
SWE-bench VerifiedFixing real GitHub issues57.6%62.3% (best)—
SimpleQA VerifiedShort factual questions—49.4% (best)15.3%
Price per million tokens
Input$1.25$2.00$1.10 (best)
Output$10.00$8.00$4.40 (best)
Cached input$0.125 (best)$0.50$0.55
Blended (3:1)$3.44$3.50$1.93 (best)
Long-context rateOver 200K: $2.50 / $15.00Same rateSame rate
Price sourceOfficial Google APIOfficial OpenAI APIOfficial OpenAI API
Limits
Context window1,048,576 tokens (best)200,000 tokens200,000 tokens
Max output65,536 tokens100,000 tokens (best)100,000 tokens (best)
Inputs and features
TextYesYesYes
ImagesYesYesNo
PDFsYesYesNo
AudioYesNoNo
VideoYesNoNo
ReasoningYesYeslow · medium · highYeslow · medium · high
Tool callingYesYesYes
Structured outputYesYesYes
Availability
WeightsProprietaryProprietaryProprietary
API model IDgemini-2.5-proo3o3-mini
API providers22 (best)1815
ReleasedJun 17, 2025Apr 16, 2025Jan 31, 2025
Knowledge cutoffJan 2025May 2024May 2024
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.

  • Gemini 2.5 Pro$32.50
  • o3$36.00
  • o3-mini$19.80
04 — Questions

Which should you choose?

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

Gemini 2.5 Pro is the better all-round choice, scoring 63/100 against o3 (58) and o3-mini (52). It leads on inputs & features and context window. o3 wins on capability. o3-mini wins on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

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

o3-mini is cheaper at $1.10 input / $4.40 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 $1.93 per million tokens for o3-mini versus $3.44 for Gemini 2.5 Pro (1.8× as much) and $3.50 for o3 (1.8× as much).

Which scores higher on benchmarks?

o3 scores higher on the Capabilities Index (ECI): o3 146.9 (#63 of 148), Gemini 2.5 Pro 145.3 (#78 of 148) and o3-mini 140.3 (#98 of 148). The confidence ranges of the top two overlap (144.9–148.6 vs 143.6–146.9), so treat the gap as small. On individual benchmarks: GPQA Diamond — Gemini 2.5 Pro 85.3%, o3 81.8%, o3-mini 77.0%; FrontierMath Tiers 1–3 — o3 33.3%, Gemini 2.5 Pro 24.6%, o3-mini 18.6%; OTIS Mock AIME 2024–2025 — Gemini 2.5 Pro 84.7%, o3 84.4%, o3-mini 76.9%.

Which is better for coding?

There are no published SWE-bench Verified results for o3-mini yet, so there is no like-for-like coding score. On overall capability, o3 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 200,000 for o3 and 200,000 for o3-mini. Maximum output per response: Gemini 2.5 Pro up to 65,536, o3 up to 100,000, o3-mini up to 100,000 tokens.

Which can read images, PDFs, audio or video?

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

Are any of these open source?

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

Which is newer?

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

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.