Model Comparison

Seed 2.1 Pro vs DeepSeek-V4-Flash-MaxWhich is better in 2026?

Seed 2.1 Pro significantly outperforms across most benchmarks.

Verdict: Seed 2.1 Pro vs DeepSeek-V4-Flash-Max — which is better?

Seed 2.1 Pro (by ByteDance) and DeepSeek-V4-Flash-Max (by DeepSeek) 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.

Seed 2.1 Pro outperforms in 5 benchmarks (BrowseComp, Humanity's Last Exam, MCP Atlas, SWE-Bench Pro, Toolathlon), while DeepSeek-V4-Flash-Max is better at 1 benchmark (MathArena Apex). Seed 2.1 Pro significantly outperforms across most benchmarks.

Choose Seed 2.1 Pro if…

  • you want the strongest raw capability — it leads on 5 of 6 shared benchmarks
  • you want the most recent training data — it shipped Jun 2026

Choose DeepSeek-V4-Flash-Max if…

  • you need open weights you can self-host or fine-tune

Performance Benchmarks

Comparative analysis across standard metrics

6 benchmarks

Seed 2.1 Pro outperforms in 5 benchmarks (BrowseComp, Humanity's Last Exam, MCP Atlas, SWE-Bench Pro, Toolathlon), while DeepSeek-V4-Flash-Max is better at 1 benchmark (MathArena Apex).

Seed 2.1 Pro significantly outperforms across most benchmarks.

Fri Jul 17 2026 • llm-stats.com

Arena Performance

Human preference votes

Context Window

Maximum input and output token capacity

Only DeepSeek-V4-Flash-Max specifies input context (1,048,576 tokens). Only DeepSeek-V4-Flash-Max specifies output context (65,536 tokens).

ByteDance
Seed 2.1 Pro
Input- tokens
Output- tokens
DeepSeek
DeepSeek-V4-Flash-Max
Input1,048,576 tokens
Output65,536 tokens
Fri Jul 17 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Seed 2.1 Pro supports multimodal inputs, whereas DeepSeek-V4-Flash-Max does not.

Seed 2.1 Pro can handle both text and other forms of data like images, making it suitable for multimodal applications.

Seed 2.1 Pro

Text
Images
Audio
Video

DeepSeek-V4-Flash-Max

Text
Images
Audio
Video

License

Usage and distribution terms

Seed 2.1 Pro is licensed under a proprietary license, while DeepSeek-V4-Flash-Max uses MIT.

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

Seed 2.1 Pro

Proprietary

Closed source

DeepSeek-V4-Flash-Max

MIT

Open weights

Release Timeline

When each model was launched

Seed 2.1 Pro was released on 2026-06-24, while DeepSeek-V4-Flash-Max was released on 2026-04-23.

Seed 2.1 Pro is 2 months newer than DeepSeek-V4-Flash-Max.

Seed 2.1 Pro

Jun 24, 2026

3 weeks ago

2mo newer
DeepSeek-V4-Flash-Max

Apr 23, 2026

2 months ago

Knowledge Cutoff

When training data ends

Neither model specifies a knowledge cutoff date.

Unable to compare the recency of their training data.

No cutoff dates available

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Key Takeaways

ByteDance
Supports multimodal inputs
Higher BrowseComp score (86.2% vs 73.2%)
Higher Humanity's Last Exam score (55.7% vs 45.1%)
Higher MCP Atlas score (83.8% vs 69.0%)
Higher SWE-Bench Pro score (57.5% vs 52.6%)
Higher Toolathlon score (50.6% vs 47.8%)
DeepSeek
Larger context window (1,048,576 tokens)
Has open weights
Higher MathArena Apex score (85.7% vs 31.3%)

Detailed Comparison

Interactive Arena

Judge for yourself.

Run your own prompts against Seed 2.1 Pro and DeepSeek-V4-Flash-Max side-by-side, then vote on the output you prefer.

Seed 2.1 Pro
✓ Preferred
DeepSeek-V4-Flash-Max
Open in Playground
AI Model Comparison Table
Feature
ByteDance
Seed 2.1 Pro
DeepSeek
DeepSeek-V4-Flash-Max

FAQ

Common questions about Seed 2.1 Pro vs DeepSeek-V4-Flash-Max.

Which is better, Seed 2.1 Pro or DeepSeek-V4-Flash-Max?

Seed 2.1 Pro significantly outperforms across most benchmarks. Seed 2.1 Pro is made by ByteDance and DeepSeek-V4-Flash-Max is made by DeepSeek. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does Seed 2.1 Pro compare to DeepSeek-V4-Flash-Max in benchmarks?

Seed 2.1 Pro scores CharXiv-D: 95.5%, MathVision: 94.5%, MathVista: 90.7%, MathVerse: 89.7%, Video-MME: 89.2%. DeepSeek-V4-Flash-Max scores CodeForces: 100.0%, HMMT Feb 26: 94.8%, LiveCodeBench: 91.6%, IMO-AnswerBench: 88.4%, GPQA: 88.1%.

What are the context window sizes for Seed 2.1 Pro and DeepSeek-V4-Flash-Max?

Seed 2.1 Pro supports an unknown number of tokens and DeepSeek-V4-Flash-Max supports 1.0M tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Seed 2.1 Pro and DeepSeek-V4-Flash-Max?

Key differences include multimodal support (yes vs no), licensing (Proprietary vs MIT). See the full comparison above for benchmark-by-benchmark results.

Who makes Seed 2.1 Pro and DeepSeek-V4-Flash-Max?

Seed 2.1 Pro is developed by ByteDance and DeepSeek-V4-Flash-Max is developed by DeepSeek.

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