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Comparison · 2 models · Updated Oct 4, 2026

Gemini 3.1 Flash Lite vs Seed 2.1 Pro

Gemini 3.1 Flash Lite comes out ahead, 73 to 50 on our weighted score, and it is the cheaper option too.

  1. Our pick

    Google

    Gemini 3.1 Flash Lite

    Released May 7, 2026

    73/100
    • ECI—
    • Price$0.25 / $1.50
    • Context1.05M
  2. ByteDance Seed

    Seed 2.1 Pro

    Released Jun 23, 2026

    50/100
    • ECI—
    • Price$0.891 / $4.45
    • Context256K
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    Make it a three-way comparison.

01 — Verdict

Gemini 3.1 Flash Lite is our pick

Gemini 3.1 Flash Lite is the better all-round choice, scoring 73/100 against Seed 2.1 Pro (50). It leads on price, inputs & features and context window. The score weighs price 50%, inputs & features 30%, context window 20%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.

  • CapabilityNot enough dataNo independent benchmark covers every model here yet
  • Lowest priceGemini 3.1 Flash LiteGemini 3.1 Flash Lite $0.563 · Seed 2.1 Pro $1.78 per 1M tokens (3:1 blend)
  • Longest contextGemini 3.1 Flash LiteGemini 3.1 Flash Lite 1,048,576 · Seed 2.1 Pro 256,000 tokens
  • Widest inputsGemini 3.1 Flash LiteGemini 3.1 Flash Lite: Text, Images, PDFs, Audio, Video · Seed 2.1 Pro: Text, Images, Video
  • Self-hostingNo open weightsBoth are available only through APIs
How the score is built
MeasureWeightGemini 3.1 Flash LiteSeed 2.1 Pro
Price50%6238
Inputs & features30%10080
Context window20%6136
Overall100%73/10050/100

Left out because at least one model lacks the data: capability. The remaining weights were rescaled.

02 — Side by side

Every spec in one table

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

Gemini 3.1 Flash Lite vs Seed 2.1 Pro specifications side by side
SpecificationGemini 3.1 Flash LiteGoogleSeed 2.1 ProByteDance Seed
Capability
Capabilities Index (ECI)——
ECI rank——
Price per million tokens
Input$0.25 (best)$0.891
Output$1.50 (best)$4.45
Cached input$0.025 (best)$0.178
Blended (3:1)$0.563 (best)$1.78
Long-context rateSame rateSame rate
Price sourceOfficial Google APIOfficial Volcengine Ark API
Limits
Context window1,048,576 tokens (best)256,000 tokens
Max output65,536 tokens256,000 tokens (best)
Inputs and features
TextYesYes
ImagesYesYes
PDFsYesNo
AudioYesNo
VideoYesYes
ReasoningYesminimal · low · medium · highYesminimal · low · medium · high · xhigh · max
Tool callingYesYes
Structured outputYesYes
Availability
WeightsProprietaryProprietary
API model IDgemini-3.1-flash-litedoubao-seed-2-1-pro-260628
API providers23 (best)2
ReleasedMay 7, 2026Jun 23, 2026
Knowledge cutoffJan 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 3.1 Flash Lite$5.50
  • Seed 2.1 Pro$17.81
04 — Questions

Which should you choose?

Which is better: Gemini 3.1 Flash Lite or Seed 2.1 Pro?

Gemini 3.1 Flash Lite is the better all-round choice, scoring 73/100 against Seed 2.1 Pro (50). It leads on price, inputs & features and context window. The score weighs price 50%, inputs & features 30%, context window 20%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.

Which is cheaper, Gemini 3.1 Flash Lite or Seed 2.1 Pro?

Gemini 3.1 Flash Lite is cheaper at $0.25 input / $1.50 output per million tokens (official Google API price). Seed 2.1 Pro costs $0.891 input / $4.45 output per million tokens (official Volcengine Ark API price). At a typical mix of three input tokens to one output token, that is $0.563 per million tokens for Gemini 3.1 Flash Lite versus $1.78 for Seed 2.1 Pro (3.2× as much).

Which scores higher on benchmarks?

There is no independent benchmark that covers both models yet. Gemini 3.1 Flash Lite has not been scored yet and Seed 2.1 Pro has not been scored yet.

Which is better for coding?

There are no published SWE-bench Verified results for Gemini 3.1 Flash Lite and Seed 2.1 Pro yet, so there is no like-for-like coding score. Test both on a sample of your own tasks. Both support tool calling for agent workflows.

Which has the bigger context window?

Gemini 3.1 Flash Lite has the largest context window at 1,048,576 tokens, against 256,000 for Seed 2.1 Pro. Maximum output per response: Gemini 3.1 Flash Lite up to 65,536, Seed 2.1 Pro up to 256,000 tokens.

Which can read images, PDFs, audio or video?

Gemini 3.1 Flash Lite accepts text, images, PDFs, audio and video; Seed 2.1 Pro accepts text, images and video. Gemini 3.1 Flash Lite handles the widest range of inputs.

Are any of these open source?

No. Gemini 3.1 Flash Lite and Seed 2.1 Pro are proprietary and only available through APIs and apps.

Which is newer?

Seed 2.1 Pro is the newest, released Jun 23, 2026. Gemini 3.1 Flash Lite came out May 7, 2026. Knowledge cutoff: Gemini 3.1 Flash Lite 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.