Model Comparison

GLM-5.1 vs Seed 2.1 TurboWhich is better in 2026?

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

Verdict: GLM-5.1 vs Seed 2.1 Turbo — which is better?

GLM-5.1 (by Zhipu AI) and Seed 2.1 Turbo (by ByteDance) 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.

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.

Choose GLM-5.1 if…

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

Choose Seed 2.1 Turbo if…

  • you want the strongest raw capability — it leads on 5 of 7 shared benchmarks
  • you want the most recent training data — it shipped Jun 2026

Performance Benchmarks

Comparative analysis across standard metrics

7 benchmarks

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.

Tue Jul 28 2026 • llm-stats.com

Arena Performance

Human preference votes

Context Window

Maximum input and output token capacity

Only GLM-5.1 specifies input context (200,000 tokens). Only GLM-5.1 specifies output context (128,000 tokens).

Zhipu AI
GLM-5.1
Input200,000 tokens
Output128,000 tokens
ByteDance
Seed 2.1 Turbo
Input- tokens
Output- tokens
Tue Jul 28 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

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

3 months ago

Seed 2.1 Turbo

Jun 24, 2026

1 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?Start an Issue discussion→

Key Takeaways

Zhipu AI
Larger context window (200,000 tokens)
Has open weights
Higher CyberGym score (68.7% vs 67.0%)
Higher SWE-Bench Pro score (58.4% vs 57.0%)
ByteDance
Supports multimodal inputs
Higher BrowseComp score (84.9% vs 79.3%)
Higher Humanity's Last Exam score (54.6% vs 52.3%)
Higher MCP Atlas score (80.3% vs 71.8%)
Higher NL2Repo score (43.7% vs 42.7%)
Higher Toolathlon score (49.1% vs 40.7%)

Detailed Comparison

Interactive Arena

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
AI Model Comparison Table
Feature
Zhipu AI
GLM-5.1
ByteDance
Seed 2.1 Turbo

FAQ

Common questions about GLM-5.1 vs Seed 2.1 Turbo.

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

Seed 2.1 Turbo shows notably better performance in the majority of benchmarks. 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 benchmark scores, pricing, and capabilities 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 200K 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 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