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Comparison · 3 models · Updated Oct 4, 2026

o3-mini vs Gemini 2.5 Flash vs DeepSeek-R1

Gemini 2.5 Flash comes out ahead, 68 to 52 and 51 on our weighted score, and it is the cheaper option too.

  1. OpenAI

    o3-mini

    Released Jan 31, 2025Deprecated

    52/100
    • ECI140.3
    • Price$1.10 / $4.40
    • Context200K
    Full specs Remove o3-mini
  2. Our pick

    Google

    Gemini 2.5 Flash

    Released Jun 17, 2025

    68/100
    • ECI140.8
    • Price$0.30 / $2.50
    • Context1.05M
    Full specs Remove Gemini 2.5 Flash

  3. DeepSeek

    DeepSeek-R1

    Released Jan 20, 2025

    51/100
    • ECI139.0
    • Price$0.70 / $2.60
    • Context128K
    Full specs Remove DeepSeek-R1
01 — Verdict

Gemini 2.5 Flash is our pick

Gemini 2.5 Flash is the better all-round choice, scoring 68/100 against o3-mini (52) and DeepSeek-R1 (51). It leads on price, inputs & features and context window. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

  • CapabilityGemini 2.5 FlashCapabilities Index (ECI): Gemini 2.5 Flash 140.8 · o3-mini 140.3 · DeepSeek-R1 139.0
  • Lowest priceGemini 2.5 FlashGemini 2.5 Flash $0.85 · DeepSeek-R1 $1.18 · o3-mini $1.93 per 1M tokens (3:1 blend)
  • Longest contextGemini 2.5 FlashGemini 2.5 Flash 1,048,576 · o3-mini 200,000 · DeepSeek-R1 128,000 tokens
  • Widest inputsGemini 2.5 Flasho3-mini: Text · Gemini 2.5 Flash: Text, Images, PDFs, Audio, Video · DeepSeek-R1: Text
  • Self-hostingDeepSeek-R1Publishes downloadable weights
How the score is built
MeasureWeighto3-miniGemini 2.5 FlashDeepSeek-R1
CapabilityCapabilities Index (ECI)50%666764
Price25%365347
Inputs & features15%4510035
Context window10%326124
Overall100%52/10068/10051/100
02 — Side by side

Every spec in one table

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

o3-mini vs Gemini 2.5 Flash vs DeepSeek-R1 specifications side by side
Specificationo3-miniOpenAIGemini 2.5 FlashGoogleDeepSeek-R1DeepSeek
Capability
Capabilities Index (ECI)140.3140.8 (best)139.0
ECI rank#98 of 148#97 of 148 (best)#104 of 148
GPQA DiamondGraduate-level science questions77.0% (best)—71.7%
FrontierMath Tiers 1–3Research-level mathematics18.6%——
OTIS Mock AIME 2024–2025Competition mathematics76.9% (best)—53.3%
SimpleQA VerifiedShort factual questions15.3%——
Price per million tokens
Input$1.10$0.30 (best)$0.70
Output$4.40$2.50 (best)$2.60
Cached input$0.55$0.03 (best)—
Blended (3:1)$1.93$0.85 (best)$1.18
Long-context rateSame rateSame rateSame rate
Price sourceOfficial OpenAI APIOfficial Google APIMedian of 11 providers
Limits
Context window200,000 tokens1,048,576 tokens (best)128,000 tokens
Max output100,000 tokens (best)65,536 tokens32,768 tokens
Inputs and features
TextYesYesYes
ImagesNoYesNo
PDFsNoYesNo
AudioNoYesNo
VideoNoYesNo
ReasoningYeslow · medium · highYesYes
Tool callingYesYesYes
Structured outputYesYesNo
Availability
WeightsProprietaryProprietaryOpen
API model IDo3-minigemini-2.5-flash—
API providers1522 (best)12
ReleasedJan 31, 2025Jun 17, 2025Jan 20, 2025
Knowledge cutoffMay 2024Jan 2025Jul 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.

  • o3-mini$19.80
  • Gemini 2.5 Flash$8.00
  • DeepSeek-R1$12.20
04 — Questions

Which should you choose?

Which is better: o3-mini, Gemini 2.5 Flash or DeepSeek-R1?

Gemini 2.5 Flash is the better all-round choice, scoring 68/100 against o3-mini (52) and DeepSeek-R1 (51). It leads on price, inputs & features and context window. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

Which is cheaper, o3-mini, Gemini 2.5 Flash or DeepSeek-R1?

Gemini 2.5 Flash is cheaper at $0.30 input / $2.50 output per million tokens (official Google API price). DeepSeek-R1 costs $0.70 input / $2.60 output per million tokens (median across 11 API providers); o3-mini costs $1.10 input / $4.40 output per million tokens (official OpenAI API price). At a typical mix of three input tokens to one output token, that is $0.85 per million tokens for Gemini 2.5 Flash versus $1.18 for DeepSeek-R1 (1.4× as much) and $1.93 for o3-mini (2.3× as much).

Which scores higher on benchmarks?

Gemini 2.5 Flash scores higher on the Capabilities Index (ECI): Gemini 2.5 Flash 140.8 (#97 of 148), o3-mini 140.3 (#98 of 148) and DeepSeek-R1 139.0 (#104 of 148). The confidence ranges of the top two overlap (138.5–142.3 vs 137.4–141.9), so treat the gap as small.

Which is better for coding?

There are no published SWE-bench Verified results for o3-mini, Gemini 2.5 Flash and DeepSeek-R1 yet, so there is no like-for-like coding score. On overall capability, Gemini 2.5 Flash 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 Flash has the largest context window at 1,048,576 tokens, against 200,000 for o3-mini and 128,000 for DeepSeek-R1. Maximum output per response: o3-mini up to 100,000, Gemini 2.5 Flash up to 65,536, DeepSeek-R1 up to 32,768 tokens.

Which can read images, PDFs, audio or video?

o3-mini accepts text; Gemini 2.5 Flash accepts text, images, PDFs, audio and video; DeepSeek-R1 accepts text. Gemini 2.5 Flash handles the widest range of inputs.

Are any of these open source?

DeepSeek-R1 publishes its weights and can be self-hosted; o3-mini and Gemini 2.5 Flash is proprietary.

Which is newer?

Gemini 2.5 Flash is the newest, released Jun 17, 2025. o3-mini came out Jan 31, 2025; DeepSeek-R1 came out Jan 20, 2025. Knowledge cutoff: o3-mini May 2024, Gemini 2.5 Flash Jan 2025, DeepSeek-R1 Jul 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.

05 — Keep comparing

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