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DeepSeek-V4.1-Flash vs Seed 2.1 Pro

DeepSeek-V4.1-Flash leads the LLM Stats Score 51.8 to 46.3.

DeepSeek · ByteDance · Updated for 2026

Which is better?

DeepSeek-V4.1-Flash leads the overall LLM Stats Score 51.8 to 46.3, ranking #13 overall.

In the 9 individual benchmarks reported for both models, DeepSeek-V4.1-Flash wins 6; this is a narrower head-to-head signal than the composite indexes.

Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.

Choose DeepSeek-V4.1-Flash

  • overall performance matters — it scores 51.8 and ranks #13 on LLM Stats
  • your work emphasizes coding and agents — it leads those capability indexes
  • you value its reported benchmark strengths — it wins 6 of 9 exact shared results
  • you want the most recent training data — it shipped Sep 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-V4.1-Flash
DeepSeek
Seed 2.1 Pro
ByteDance
Core performance indexes
LLM Stats Score
51.8
#13
46.3
#26
Reasoning
48.9
#18
47.5
#24
Coding
44.2
#5
33.4
#34
Agents
41.1
#4
31.9
#27
Cost, coverage & limits
Benchmark wins
6 of 9
3 of 9
Input price
$0.22 / M
— / M
Output price
$0.66 / M
— / M
Context window
1,040,000
—

Capability indexes

Additional strengths measured across groups of related public benchmarks

4 shared
Index
DeepSeek-V4.1-Flash
Seed 2.1 Pro
Math
35.2#43
40.5#14
Vision
29.5#31
34.4#12
Tool use
34.8#2
26.7#28
Multimodal
34.3#13
37.8#4
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

20 reported for DeepSeek-V4.1-Flash · 94 for Seed 2.1 Pro

9 shared

DeepSeek-V4.1-Flash outperforms in 6 benchmarks (BabyVision, CyberGym, MathArena Apex, NL2Repo, Terminal-Bench 2.1, ZEROBench), while Seed 2.1 Pro is better at 3 benchmarks (Agents' Last Exam, Humanity's Last Exam, Program Bench).

DeepSeek-V4.1-Flash shows notably better performance in the majority of benchmarks.

Sun Sep 20 2026 • llm-stats.com

Human preference

Blind head-to-head votes and playground preference scores

Context Window

Maximum input and output token capacity

Only DeepSeek-V4.1-Flash specifies input context (1,040,000 tokens). Only DeepSeek-V4.1-Flash specifies output context (393,216 tokens).

DeepSeek
DeepSeek-V4.1-Flash
Input1,040,000 tokens
Output393,216 tokens
ByteDance
Seed 2.1 Pro
Input- tokens
Output- tokens
Sun Sep 20 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Both DeepSeek-V4.1-Flash and Seed 2.1 Pro support multimodal inputs.

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

DeepSeek-V4.1-Flash

Text
Images
Audio
Video

Seed 2.1 Pro

Text
Images
Audio
Video

License

Usage and distribution terms

DeepSeek-V4.1-Flash 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-V4.1-Flash

MIT

Open weights

Seed 2.1 Pro

Proprietary

Closed source

Release Timeline

When each model was launched

DeepSeek-V4.1-Flash was released on 2026-09-10, while Seed 2.1 Pro was released on 2026-06-24.

DeepSeek-V4.1-Flash is 3 months newer than Seed 2.1 Pro.

DeepSeek-V4.1-Flash

Sep 10, 2026

1 weeks ago

2mo 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-V4.1-Flash and Seed 2.1 Pro side-by-side, then vote on the output you prefer.

DeepSeek-V4.1-Flash
✓ Preferred
Seed 2.1 Pro
Open in Playground

FAQ

Common questions about DeepSeek-V4.1-Flash vs Seed 2.1 Pro.

Which is better, DeepSeek-V4.1-Flash or Seed 2.1 Pro?

DeepSeek-V4.1-Flash leads the LLM Stats Score 51.8 to 46.3. DeepSeek-V4.1-Flash is made by DeepSeek and Seed 2.1 Pro is made by ByteDance. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does DeepSeek-V4.1-Flash compare to Seed 2.1 Pro in benchmarks?

DeepSeek-V4.1-Flash scores CodeForces: 100.0%, GPQA: 90.9%, Terminal-Bench 2.1: 90.6%, BabyVision: 89.6%, CyberGym: 88.1%. 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-V4.1-Flash and Seed 2.1 Pro?

DeepSeek-V4.1-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.

What are the main differences between DeepSeek-V4.1-Flash and Seed 2.1 Pro?

Key differences include LLM Stats Score (51.8 vs 46.3), licensing (MIT vs Proprietary). See the full comparison above for benchmark-by-benchmark results.

Who makes DeepSeek-V4.1-Flash and Seed 2.1 Pro?

DeepSeek-V4.1-Flash is developed by DeepSeek and Seed 2.1 Pro is developed by ByteDance.

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