Model Comparison

Seed 2.0 Pro vs Step-3.5-Flash

Seed 2.0 Pro significantly outperforms across most benchmarks.

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Performance Benchmarks

Comparative analysis across standard metrics

4 benchmarks

Seed 2.0 Pro outperforms in 4 benchmarks (AIME 2025, BrowseComp, LiveCodeBench v6, SWE-Bench Verified), while Step-3.5-Flash is better at 0 benchmarks.

Seed 2.0 Pro significantly outperforms across most benchmarks.

Fri Apr 17 2026 • llm-stats.com

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

Cost data unavailable.

Lowest available price from all providers
Fri Apr 17 2026 • llm-stats.com
ByteDance
Seed 2.0 Pro
Input tokens$0.00
Output tokens$0.00
Best providerUnknown Organization
StepFun
Step-3.5-Flash
Input tokens$0.10
Output tokens$0.40
Best providerStepFun
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

Only Step-3.5-Flash specifies input context (65,536 tokens). Only Step-3.5-Flash specifies output context (8,192 tokens).

ByteDance
Seed 2.0 Pro
Input- tokens
Output- tokens
StepFun
Step-3.5-Flash
Input65,536 tokens
Output8,192 tokens
Fri Apr 17 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Seed 2.0 Pro supports multimodal inputs, whereas Step-3.5-Flash does not.

Seed 2.0 Pro can handle both text and other forms of data like images, making it suitable for multimodal applications.

Seed 2.0 Pro

Text
Images
Audio
Video

Step-3.5-Flash

Text
Images
Audio
Video

License

Usage and distribution terms

Seed 2.0 Pro is licensed under a proprietary license, while Step-3.5-Flash uses Apache 2.0.

License differences may affect how you can use these models in commercial or open-source projects.

Seed 2.0 Pro

Proprietary

Closed source

Step-3.5-Flash

Apache 2.0

Open weights

Release Timeline

When each model was launched

Seed 2.0 Pro was released on 2026-02-14, while Step-3.5-Flash was released on 2026-02-02.

Seed 2.0 Pro is 0 month newer than Step-3.5-Flash.

Seed 2.0 Pro

Feb 14, 2026

2 months ago

1w newer
Step-3.5-Flash

Feb 2, 2026

2 months ago

Knowledge Cutoff

When training data ends

Seed 2.0 Pro has a documented knowledge cutoff of 2024-01-01, while Step-3.5-Flash's cutoff date is not specified.

We can confirm Seed 2.0 Pro's training data extends to 2024-01-01, but cannot make a direct comparison without Step-3.5-Flash's cutoff date.

Seed 2.0 Pro

Jan 2024

Step-3.5-Flash

—

Outputs Comparison

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Key Takeaways

ByteDance
Supports multimodal inputs
Higher AIME 2025 score (98.3% vs 97.3%)
Higher BrowseComp score (77.3% vs 69.0%)
Higher LiveCodeBench v6 score (87.8% vs 86.4%)
Higher SWE-Bench Verified score (76.5% vs 74.4%)
StepFun
Larger context window (65,536 tokens)
Has open weights

Detailed Comparison

AI Model Comparison Table
Feature
ByteDance
Seed 2.0 Pro
StepFun
Step-3.5-Flash

FAQ

Common questions about Seed 2.0 Pro vs Step-3.5-Flash

Seed 2.0 Pro significantly outperforms across most benchmarks. Seed 2.0 Pro is made by ByteDance and Step-3.5-Flash is made by StepFun. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.
Seed 2.0 Pro scores AIME 2025: 98.3%, AIME 2026: 94.2%, GPQA: 88.9%, LiveCodeBench v6: 87.8%, BrowseComp: 77.3%. Step-3.5-Flash scores AIME 2025: 97.3%, Tau-bench: 88.2%, LiveCodeBench v6: 86.4%, IMO-AnswerBench: 85.4%, SWE-Bench Verified: 74.4%.
Seed 2.0 Pro supports an unknown number of tokens and Step-3.5-Flash supports 66K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.
Key differences include multimodal support (yes vs no), licensing (Proprietary vs Apache 2.0). See the full comparison above for benchmark-by-benchmark results.
Seed 2.0 Pro is developed by ByteDance and Step-3.5-Flash is developed by StepFun.