The AI arena is free today

Open Superagent

GLM-5.1 vs Seed 2.1 Turbo

GLM-5.1 and Seed 2.1 Turbo are closely matched at 39.1 and 43.0 on the LLM Stats Score.

Zhipu AI · ByteDance · Updated for 2026

Which is better?

GLM-5.1 and Seed 2.1 Turbo are closely matched on the overall LLM Stats Score at 39.1 and 43.0.

In the 7 individual benchmarks reported for both models, Seed 2.1 Turbo wins 5; 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 GLM-5.1

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

Choose Seed 2.1 Turbo

  • your work emphasizes reasoning — it leads those capability indexes
  • you value its reported benchmark strengths — it wins 5 of 7 exact shared results
  • you want the most recent training data — it shipped Jun 2026

At a glance

The differences that matter most.

GLM-5.1
Zhipu AI
Seed 2.1 Turbo
ByteDance
Core performance indexes
LLM Stats Score
39.1
#66
43.0
#48
Reasoning
38.8
#66
44.4
#37
Coding
30.0
#58
30.5
#53
Agents
23.8
#61
28.9
#44
Cost, coverage & limits
Benchmark wins
2 of 7
5 of 7
Input price
$1.05 / M
— / M
Output price
$3.50 / M
— / M
Context window
202,752
—

Capability indexes

Additional strengths measured across groups of related public benchmarks

2 shared
Index
GLM-5.1
Seed 2.1 Turbo
Math
33.1#56
39.6#18
Tool use
19.1#65
19.3#62
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

18 reported for GLM-5.1 · 90 for Seed 2.1 Turbo

7 shared

GLM-5.1 outperforms in 2 benchmarks (CyberGym, SWE-Bench Pro), while Seed 2.1 Turbo is better at 5 benchmarks (BrowseComp, Humanity's Last Exam, MCP Atlas, NL2Repo, Toolathlon).

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

Fri Oct 02 2026 • llm-stats.com

Human preference

Blind head-to-head votes and playground preference scores

Context Window

Maximum input and output token capacity

Only GLM-5.1 specifies input context (202,752 tokens). Only GLM-5.1 specifies output context (202,752 tokens).

Zhipu AI
GLM-5.1
Input202,752 tokens
Output202,752 tokens
ByteDance
Seed 2.1 Turbo
Input- tokens
Output- tokens
Fri Oct 02 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Seed 2.1 Turbo supports multimodal inputs, whereas GLM-5.1 does not.

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

GLM-5.1

Text
Images
Audio
Video

Seed 2.1 Turbo

Text
Images
Audio
Video

License

Usage and distribution terms

GLM-5.1 is licensed under MIT, while Seed 2.1 Turbo uses a proprietary license.

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

GLM-5.1

MIT

Open weights

Seed 2.1 Turbo

Proprietary

Closed source

Release Timeline

When each model was launched

GLM-5.1 was released on 2026-04-07, while Seed 2.1 Turbo was released on 2026-06-24.

Seed 2.1 Turbo is 3 months newer than GLM-5.1.

GLM-5.1

Apr 7, 2026

5 months ago

Seed 2.1 Turbo

Jun 24, 2026

3 months ago

2mo newer

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?

Judge for yourself.

Run your own prompts against GLM-5.1 and Seed 2.1 Turbo side-by-side, then vote on the output you prefer.

GLM-5.1
✓ Preferred
Seed 2.1 Turbo
Open in Playground

FAQ

Common questions about GLM-5.1 vs Seed 2.1 Turbo.

Which is better, GLM-5.1 or Seed 2.1 Turbo?

GLM-5.1 and Seed 2.1 Turbo are closely matched on the LLM Stats Score at 39.1 and 43.0. GLM-5.1 is made by Zhipu AI and Seed 2.1 Turbo is made by ByteDance. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does GLM-5.1 compare to Seed 2.1 Turbo in benchmarks?

GLM-5.1 scores Vending-Bench 2: 100.0%, AIME 2026: 95.3%, HMMT 2025: 94.0%, GPQA: 86.2%, IMO-AnswerBench: 83.8%. Seed 2.1 Turbo scores CharXiv-D: 94.6%, MathVision: 92.7%, MathVista: 90.5%, MathVerse: 89.2%, Video-MME: 89.0%.

What are the context window sizes for GLM-5.1 and Seed 2.1 Turbo?

GLM-5.1 supports 203K tokens and Seed 2.1 Turbo 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 GLM-5.1 and Seed 2.1 Turbo?

Key differences include LLM Stats Score (39.1 vs 43.0), multimodal support (no vs yes), licensing (MIT vs Proprietary). See the full comparison above for benchmark-by-benchmark results.

Who makes GLM-5.1 and Seed 2.1 Turbo?

GLM-5.1 is developed by Zhipu AI and Seed 2.1 Turbo is developed by ByteDance.

Related comparisons