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Comparison · 2 models · Updated Oct 4, 2026

DeepSeek-V3.1 vs Gemini 3 Flash Preview

Gemini 3 Flash Preview comes out ahead, 73 to 55 on our weighted score, though DeepSeek-V3.1 is 47% cheaper per token.

  1. DeepSeek

    DeepSeek-V3.1

    Released Aug 21, 2025

    55/100
    • ECI139.9
    • Price$0.385 / $1.25
    • Context131K
    Full specs Remove DeepSeek-V3.1
  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 DeepSeek-V3.1 (55). It leads on capability, inputs & features and context window. DeepSeek-V3.1 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 · DeepSeek-V3.1 139.9
  • Lowest priceDeepSeek-V3.1DeepSeek-V3.1 $0.601 · Gemini 3 Flash Preview $1.13 per 1M tokens (3:1 blend)
  • Longest contextGemini 3 Flash PreviewGemini 3 Flash Preview 1,048,576 · DeepSeek-V3.1 131,072 tokens
  • Widest inputsGemini 3 Flash PreviewDeepSeek-V3.1: Text · Gemini 3 Flash Preview: Text, Images, PDFs, Audio, Video
  • Self-hostingDeepSeek-V3.1Publishes downloadable weights (MIT License)
How the score is built
MeasureWeightDeepSeek-V3.1Gemini 3 Flash Preview
CapabilityCapabilities Index (ECI)50%6580
Price25%6047
Inputs & features15%35100
Context window10%2461
Overall100%55/10073/100
02 — Side by side

Every spec in one table

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

DeepSeek-V3.1 vs Gemini 3 Flash Preview specifications side by side
SpecificationDeepSeek-V3.1DeepSeekGemini 3 Flash PreviewGoogle
Capability
Capabilities Index (ECI)139.9151.8 (best)
ECI rank#100 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$0.385 (best)$0.50
Output$1.25 (best)$3.00
Cached input—$0.05
Blended (3:1)$0.601 (best)$1.13
Long-context rateSame rateSame rate
Price sourceMedian of 8 providersOfficial Google API
Limits
Context window131,072 tokens1,048,576 tokens (best)
Max output8,192 tokens65,536 tokens (best)
Inputs and features
TextYesYes
ImagesNoYes
PDFsNoYes
AudioNoYes
VideoNoYes
ReasoningYesYesminimal · low · medium · high
Tool callingYesYes
Structured outputNoYes
Availability
WeightsOpenMIT LicenseProprietary
API model ID—gemini-3-flash-preview
API providers820 (best)
ReleasedAug 21, 2025Dec 17, 2025
Knowledge cutoff—Jan 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.

  • DeepSeek-V3.1$6.35
  • Gemini 3 Flash Preview$11.00
04 — Questions

Which should you choose?

Which is better: DeepSeek-V3.1 or Gemini 3 Flash Preview?

Gemini 3 Flash Preview is the better all-round choice, scoring 73/100 against DeepSeek-V3.1 (55). It leads on capability, inputs & features and context window. DeepSeek-V3.1 wins on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

Which is cheaper, DeepSeek-V3.1 or Gemini 3 Flash Preview?

DeepSeek-V3.1 is cheaper at $0.385 input / $1.25 output per million tokens (median across 8 API providers). 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 $0.601 per million tokens for DeepSeek-V3.1 versus $1.13 for Gemini 3 Flash Preview (1.9× 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 DeepSeek-V3.1 139.9 (#100 of 148). Their confidence ranges do not overlap (150.4–153.7 vs 136.1–143.3), so the gap is a real one.

Which is better for coding?

There are no published SWE-bench Verified results for DeepSeek-V3.1 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 3 Flash Preview has the largest context window at 1,048,576 tokens, against 131,072 for DeepSeek-V3.1. Maximum output per response: DeepSeek-V3.1 up to 8,192, Gemini 3 Flash Preview up to 65,536 tokens.

Which can read images, PDFs, audio or video?

DeepSeek-V3.1 accepts text; Gemini 3 Flash Preview accepts text, images, PDFs, audio and video. Gemini 3 Flash Preview handles the widest range of inputs.

Are any of these open source?

DeepSeek-V3.1 publishes its weights (MIT License) and can be self-hosted; Gemini 3 Flash Preview is proprietary.

Which is newer?

Gemini 3 Flash Preview is the newest, released Dec 17, 2025. DeepSeek-V3.1 came out Aug 21, 2025. Knowledge cutoff: 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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