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Beam 1.0 vs Seed 2.1 Pro

Beam 1.0 and Seed 2.1 Pro are closely matched at 44.6 and 45.7 on the LLM Stats Score.

Reflection AI · ByteDance · Updated for 2026

Which is better?

Beam 1.0 and Seed 2.1 Pro are closely matched on the overall LLM Stats Score at 44.6 and 45.7.

In the 6 individual benchmarks reported for both models, Seed 2.1 Pro wins 4; 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 Beam 1.0

  • you want the most recent training data — it shipped Oct 2026
  • you need open weights you can self-host or fine-tune

Choose Seed 2.1 Pro

  • you value its reported benchmark strengths — it wins 4 of 6 exact shared results

At a glance

The differences that matter most.

Beam 1.0
Reflection AI
Seed 2.1 Pro
ByteDance
Core performance indexes
LLM Stats Score
44.6
#46
45.7
#40
Reasoning
45.5
#37
47.2
#26
Coding
33.7
#39
32.0
#49
Agents
28.8
#53
31.0
#42
Cost, coverage & limits
Benchmark wins
2 of 6
4 of 6
Input price
$0.40 / M
— / M
Output price
$1.20 / M
— / M
Context window
1,048,576
—

Capability indexes

Additional strengths measured across groups of related public benchmarks

4 shared
Index
Beam 1.0
Seed 2.1 Pro
Math
35.1#45
40.2#15
Vision
15.9#105
34.5#15
Tool use
26.4#32
24.8#38
Long context
29.5#5
29.0#6
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

22 reported for Beam 1.0 · 94 for Seed 2.1 Pro

6 shared

Beam 1.0 outperforms in 2 benchmarks (SWE-Bench Pro, Terminal-Bench 2.1), while Seed 2.1 Pro is better at 4 benchmarks (BrowseComp, Humanity's Last Exam, MCP Atlas, SciCode).

Seed 2.1 Pro shows notably better performance in the majority of benchmarks.

Sat Oct 24 2026 • llm-stats.com

Human preference

Blind head-to-head votes and playground preference scores

Context Window

Maximum input and output token capacity

Only Beam 1.0 specifies input context (1,048,576 tokens). Only Beam 1.0 specifies output context (131,072 tokens).

Reflection AI
Beam 1.0
Input1,048,576 tokens
Output131,072 tokens
ByteDance
Seed 2.1 Pro
Input- tokens
Output- tokens
Sat Oct 24 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Seed 2.1 Pro supports multimodal inputs, whereas Beam 1.0 does not.

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

Beam 1.0

Text
Images
Audio
Video

Seed 2.1 Pro

Text
Images
Audio
Video

License

Usage and distribution terms

Beam 1.0 is licensed under Apache 2.0, 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.

Beam 1.0

Apache 2.0

Open weights

Seed 2.1 Pro

Proprietary

Closed source

Release Timeline

When each model was launched

Beam 1.0 was released on 2026-10-16, while Seed 2.1 Pro was released on 2026-06-24.

Beam 1.0 is 4 months newer than Seed 2.1 Pro.

Beam 1.0

Oct 16, 2026

4 days ago

3mo newer
Seed 2.1 Pro

Jun 24, 2026

3 months ago

Knowledge Cutoff

When training data ends

Beam 1.0 has a documented knowledge cutoff of 2026-06-30, while Seed 2.1 Pro's cutoff date is not specified.

We can confirm Beam 1.0's training data extends to 2026-06-30, but cannot make a direct comparison without Seed 2.1 Pro's cutoff date.

Beam 1.0

Jun 2026

Seed 2.1 Pro

—

Outputs Comparison

Notice missing or incorrect data?

Judge for yourself.

Run your own prompts against Beam 1.0 and Seed 2.1 Pro side-by-side, then vote on the output you prefer.

Beam 1.0
✓ Preferred
Seed 2.1 Pro
Open in Playground

FAQ

Common questions about Beam 1.0 vs Seed 2.1 Pro.

Which is better, Beam 1.0 or Seed 2.1 Pro?

Beam 1.0 and Seed 2.1 Pro are closely matched on the LLM Stats Score at 44.6 and 45.7. Beam 1.0 is made by Reflection AI 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 Beam 1.0 compare to Seed 2.1 Pro in benchmarks?

Beam 1.0 scores AIME 2026: 97.7%, GPQA: 90.6%, LiveCodeBench: 88.3%, SWE-Bench Verified: 81.6%, MCP Atlas: 80.8%. 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 Beam 1.0 and Seed 2.1 Pro?

Beam 1.0 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 Beam 1.0 and Seed 2.1 Pro?

Key differences include LLM Stats Score (44.6 vs 45.7), multimodal support (no vs yes), licensing (Apache 2.0 vs Proprietary). See the full comparison above for benchmark-by-benchmark results.

Who makes Beam 1.0 and Seed 2.1 Pro?

Beam 1.0 is developed by Reflection AI and Seed 2.1 Pro is developed by ByteDance.

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