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Comparison · 2 models · Updated Oct 4, 2026

Gemini 2.5 Flash vs Gemini 3 Flash Preview

Gemini 3 Flash Preview comes out ahead, 73 to 68 on our weighted score, though Gemini 2.5 Flash is 24% cheaper per token.

  1. 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
  2. Our pick

    Google

    Gemini 3 Flash Preview

    Released Dec 17, 2025

    73/100
    • ECI151.8
    • Price$0.50 / $3.00
    • Context1.05M
    Full specs Remove Gemini 3 Flash Preview

  3. Add a model

    Make it a three-way comparison.

01 — Verdict

Gemini 3 Flash Preview is our pick

Gemini 3 Flash Preview is the better all-round choice, scoring 73/100 against Gemini 2.5 Flash (68). It leads on capability. Gemini 2.5 Flash wins on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

  • CapabilityGemini 3 Flash PreviewCapabilities Index (ECI): Gemini 3 Flash Preview 151.8 · Gemini 2.5 Flash 140.8
  • Lowest priceGemini 2.5 FlashGemini 2.5 Flash $0.85 · Gemini 3 Flash Preview $1.13 per 1M tokens (3:1 blend)
  • Longest contextAbout the sameGemini 2.5 Flash 1,048,576 · Gemini 3 Flash Preview 1,048,576 tokens
  • Widest inputsSame inputsGemini 2.5 Flash: Text, Images, PDFs, Audio, Video · Gemini 3 Flash Preview: Text, Images, PDFs, Audio, Video
  • Self-hostingNo open weightsBoth are available only through APIs
How the score is built
MeasureWeightGemini 2.5 FlashGemini 3 Flash Preview
CapabilityCapabilities Index (ECI)50%6780
Price25%5347
Inputs & features15%100100
Context window10%6161
Overall100%68/10073/100
02 — Side by side

Every spec in one table

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

Gemini 2.5 Flash vs Gemini 3 Flash Preview specifications side by side
SpecificationGemini 2.5 FlashGoogleGemini 3 Flash PreviewGoogle
Capability
Capabilities Index (ECI)140.8151.8 (best)
ECI rank#97 of 148#43 of 148 (best)
GPQA DiamondGraduate-level science questions—89.4%
FrontierMath Tiers 1–3Research-level mathematics—51.2%
OTIS Mock AIME 2024–2025Competition mathematics—95.6%
SWE-bench VerifiedFixing real GitHub issues—75.4%
SimpleQA VerifiedShort factual questions—66.8%
Price per million tokens
Input$0.30 (best)$0.50
Output$2.50 (best)$3.00
Cached input$0.03 (best)$0.05
Blended (3:1)$0.85 (best)$1.13
Long-context rateSame rateSame rate
Price sourceOfficial Google APIOfficial Google API
Limits
Context window1,048,576 tokens1,048,576 tokens
Max output65,536 tokens65,536 tokens
Inputs and features
TextYesYes
ImagesYesYes
PDFsYesYes
AudioYesYes
VideoYesYes
ReasoningYesYesminimal · low · medium · high
Tool callingYesYes
Structured outputYesYes
Availability
WeightsProprietaryProprietary
API model IDgemini-2.5-flashgemini-3-flash-preview
API providers22 (best)20
ReleasedJun 17, 2025Dec 17, 2025
Knowledge cutoffJan 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.

  • Gemini 2.5 Flash$8.00
  • Gemini 3 Flash Preview$11.00
04 — Questions

Which should you choose?

Which is better: Gemini 2.5 Flash or Gemini 3 Flash Preview?

Gemini 3 Flash Preview is the better all-round choice, scoring 73/100 against Gemini 2.5 Flash (68). It leads on capability. Gemini 2.5 Flash wins on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

Which is cheaper, Gemini 2.5 Flash or Gemini 3 Flash Preview?

Gemini 2.5 Flash is cheaper at $0.30 input / $2.50 output per million tokens (official Google API price). Gemini 3 Flash Preview costs $0.50 input / $3.00 output per million tokens (official Google 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 $1.13 for Gemini 3 Flash Preview (1.3× as much).

Which scores higher on benchmarks?

Gemini 3 Flash Preview scores higher on the Capabilities Index (ECI): Gemini 3 Flash Preview 151.8 (#43 of 148) and Gemini 2.5 Flash 140.8 (#97 of 148). Their confidence ranges do not overlap (150.4–153.7 vs 138.5–142.3), so the gap is a real one.

Which is better for coding?

There are no published SWE-bench Verified results for Gemini 2.5 Flash yet, so there is no like-for-like coding score. On overall capability, Gemini 3 Flash Preview leads, which tends to carry over to coding, but test on your own codebase. Both support tool calling for agent workflows.

Which has the bigger context window?

Gemini 2.5 Flash and Gemini 3 Flash Preview share the same 1,048,576-token context window. Maximum output per response: Gemini 2.5 Flash up to 65,536, Gemini 3 Flash Preview up to 65,536 tokens.

Which can read images, PDFs, audio or video?

Gemini 2.5 Flash accepts text, images, PDFs, audio and video; Gemini 3 Flash Preview accepts text, images, PDFs, audio and video. They handle the same number of input types.

Are any of these open source?

No. Gemini 2.5 Flash and Gemini 3 Flash Preview are proprietary and only available through APIs and apps.

Which is newer?

Gemini 3 Flash Preview is the newest, released Dec 17, 2025. Gemini 2.5 Flash came out Jun 17, 2025. Knowledge cutoff: Gemini 2.5 Flash Jan 2025, Gemini 3 Flash Preview 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.

05 — Keep comparing

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