Model Comparison

Gemini 3 Flash vs Seed 2.1 ProWhich is better in 2026?

Seed 2.1 Pro significantly outperforms across most benchmarks.

Verdict: Gemini 3 Flash vs Seed 2.1 Pro — which is better?

Gemini 3 Flash (by Google) and Seed 2.1 Pro (by ByteDance) are two of the AI models people compare most. Here is how they stack up on benchmarks, price and capabilities, and which one to pick in 2026.

Gemini 3 Flash outperforms in 0 benchmarks, while Seed 2.1 Pro is better at 5 benchmarks (CharXiv-R, Humanity's Last Exam, MCP Atlas, MMMU-Pro, Toolathlon). Seed 2.1 Pro significantly outperforms across most benchmarks.

Choose Gemini 3 Flash if…

  • you want predictable pricing at $0.50/M input and $3.00/M output

Choose Seed 2.1 Pro if…

  • you want the strongest raw capability — it leads on 5 of 5 shared benchmarks
  • you want the most recent training data — it shipped Jun 2026
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Performance Benchmarks

Comparative analysis across standard metrics

5 benchmarks

Gemini 3 Flash outperforms in 0 benchmarks, while Seed 2.1 Pro is better at 5 benchmarks (CharXiv-R, Humanity's Last Exam, MCP Atlas, MMMU-Pro, Toolathlon).

Seed 2.1 Pro significantly outperforms across most benchmarks.

Thu Jun 25 2026 • llm-stats.com

Arena Performance

Human preference votes

Context Window

Maximum input and output token capacity

Only Gemini 3 Flash specifies input context (1,000,000 tokens). Only Gemini 3 Flash specifies output context (65,536 tokens).

Google
Gemini 3 Flash
Input1,000,000 tokens
Output65,536 tokens
ByteDance
Seed 2.1 Pro
Input- tokens
Output- tokens
Thu Jun 25 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Both Gemini 3 Flash and Seed 2.1 Pro support multimodal inputs.

They are both capable of processing various types of data, offering versatility in application.

Gemini 3 Flash

Text
Images
Audio
Video

Seed 2.1 Pro

Text
Images
Audio
Video

License

Usage and distribution terms

Both models are licensed under proprietary licenses.

Both models have usage restrictions defined by their respective organizations.

Gemini 3 Flash

Proprietary

Closed source

Seed 2.1 Pro

Proprietary

Closed source

Release Timeline

When each model was launched

Gemini 3 Flash was released on 2025-12-17, while Seed 2.1 Pro was released on 2026-06-24.

Seed 2.1 Pro is 6 months newer than Gemini 3 Flash.

Gemini 3 Flash

Dec 17, 2025

6 months ago

Seed 2.1 Pro

Jun 24, 2026

1 days ago

6mo newer

Knowledge Cutoff

When training data ends

Gemini 3 Flash has a documented knowledge cutoff of 2025-01-31, while Seed 2.1 Pro's cutoff date is not specified.

We can confirm Gemini 3 Flash's training data extends to 2025-01-31, but cannot make a direct comparison without Seed 2.1 Pro's cutoff date.

Gemini 3 Flash

Jan 2025

Seed 2.1 Pro

—

Outputs Comparison

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Key Takeaways

Google
Larger context window (1,000,000 tokens)
ByteDance
Higher CharXiv-R score (86.4% vs 80.3%)
Higher Humanity's Last Exam score (55.7% vs 43.5%)
Higher MCP Atlas score (83.8% vs 57.4%)
Higher MMMU-Pro score (82.7% vs 81.2%)
Higher Toolathlon score (50.6% vs 49.4%)

Detailed Comparison

AI Model Comparison Table
Feature
Google
Gemini 3 Flash
ByteDance
Seed 2.1 Pro

FAQ

Common questions about Gemini 3 Flash vs Seed 2.1 Pro.

Which is better, Gemini 3 Flash or Seed 2.1 Pro?

Seed 2.1 Pro significantly outperforms across most benchmarks. Gemini 3 Flash is made by Google and Seed 2.1 Pro is made by ByteDance. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does Gemini 3 Flash compare to Seed 2.1 Pro in benchmarks?

Gemini 3 Flash scores Vending-Bench 2: 100.0%, AIME 2025: 99.7%, Global PIQA: 92.8%, MMMLU: 91.8%, GPQA: 90.4%. Seed 2.1 Pro scores CharXiv-D: 95.5%, MathVision: 94.5%, MathVista: 90.7%, MathVerse: 89.7%, Video-MME: 89.2%.

What are the context window sizes for Gemini 3 Flash and Seed 2.1 Pro?

Gemini 3 Flash supports 1.0M tokens and Seed 2.1 Pro supports an unknown number of tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

Who makes Gemini 3 Flash and Seed 2.1 Pro?

Gemini 3 Flash is developed by Google and Seed 2.1 Pro is developed by ByteDance.

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