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DeepSeek-V4-Flash-0731 vs Seed 2.1 Pro

DeepSeek-V4-Flash-0731 significantly outperforms across most benchmarks.

DeepSeek · ByteDance · Updated for 2026

Which is better?

DeepSeek-V4-Flash-0731 outperforms in 5 benchmarks (CyberGym, DeepSWE, NL2Repo, Terminal-Bench 2.1, Toolathlon), while Seed 2.1 Pro is better at 1 benchmark (Agents' Last Exam). DeepSeek-V4-Flash-0731 significantly outperforms across most benchmarks.

Based on current benchmark, pricing, and model metadata for 2026.

Choose DeepSeek-V4-Flash-0731

  • you want the strongest raw capability — it leads on 5 of 6 shared benchmarks
  • you want the most recent training data — it shipped Jul 2026
  • you need open weights you can self-host or fine-tune

Choose Seed 2.1 Pro

  • you are already invested in the ByteDance ecosystem

At a glance

The differences that matter most.

DeepSeek-V4-Flash-0731
DeepSeek
Seed 2.1 Pro
ByteDance
Benchmark wins
5 of 6
1 of 6
Input price
$0.09 / M
— / M
Output price
$0.18 / M
— / M
Context window
1,048,576
—
Released
Jul 2026
Jun 2026
License
MIT
Proprietary

Performance Benchmarks

Comparative analysis across standard metrics

6 benchmarks

DeepSeek-V4-Flash-0731 outperforms in 5 benchmarks (CyberGym, DeepSWE, NL2Repo, Terminal-Bench 2.1, Toolathlon), while Seed 2.1 Pro is better at 1 benchmark (Agents' Last Exam).

DeepSeek-V4-Flash-0731 significantly outperforms across most benchmarks.

Mon Aug 24 2026 • llm-stats.com

Arena Performance

Playground indexes and blind preference scores

Context Window

Maximum input and output token capacity

Only DeepSeek-V4-Flash-0731 specifies input context (1,048,576 tokens). Only DeepSeek-V4-Flash-0731 specifies output context (65,536 tokens).

DeepSeek
DeepSeek-V4-Flash-0731
Input1,048,576 tokens
Output65,536 tokens
ByteDance
Seed 2.1 Pro
Input- tokens
Output- tokens
Mon Aug 24 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Seed 2.1 Pro supports multimodal inputs, whereas DeepSeek-V4-Flash-0731 does not.

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

DeepSeek-V4-Flash-0731

Text
Images
Audio
Video

Seed 2.1 Pro

Text
Images
Audio
Video

License

Usage and distribution terms

DeepSeek-V4-Flash-0731 is licensed under MIT, while Seed 2.1 Pro uses a proprietary license.

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

DeepSeek-V4-Flash-0731

MIT

Open weights

Seed 2.1 Pro

Proprietary

Closed source

Release Timeline

When each model was launched

DeepSeek-V4-Flash-0731 was released on 2026-07-31, while Seed 2.1 Pro was released on 2026-06-24.

DeepSeek-V4-Flash-0731 is 1 month newer than Seed 2.1 Pro.

DeepSeek-V4-Flash-0731

Jul 31, 2026

3 weeks ago

1mo newer
Seed 2.1 Pro

Jun 24, 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→

Judge for yourself.

Run your own prompts against DeepSeek-V4-Flash-0731 and Seed 2.1 Pro side-by-side, then vote on the output you prefer.

DeepSeek-V4-Flash-0731
✓ Preferred
Seed 2.1 Pro
Open in Playground

FAQ

Common questions about DeepSeek-V4-Flash-0731 vs Seed 2.1 Pro.

Which is better, DeepSeek-V4-Flash-0731 or Seed 2.1 Pro?

DeepSeek-V4-Flash-0731 significantly outperforms across most benchmarks. DeepSeek-V4-Flash-0731 is made by DeepSeek 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 DeepSeek-V4-Flash-0731 compare to Seed 2.1 Pro in benchmarks?

DeepSeek-V4-Flash-0731 scores Terminal-Bench 2.1: 82.7%, CyberGym: 76.7%, Toolathlon: 70.3%, DSBench-FullStack: 68.7%, DSBench-Hard: 59.6%. 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 DeepSeek-V4-Flash-0731 and Seed 2.1 Pro?

DeepSeek-V4-Flash-0731 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.

What are the main differences between DeepSeek-V4-Flash-0731 and Seed 2.1 Pro?

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

Who makes DeepSeek-V4-Flash-0731 and Seed 2.1 Pro?

DeepSeek-V4-Flash-0731 is developed by DeepSeek and Seed 2.1 Pro is developed by ByteDance.

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