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GLM-5.3 vs Seed 2.1 Pro

GLM-5.3 leads the LLM Stats Score 53.6 to 46.4.

Zhipu AI · ByteDance · Updated for 2026

Which is better?

GLM-5.3 leads the overall LLM Stats Score 53.6 to 46.4, ranking #9 overall.

In the 8 individual benchmarks reported for both models, GLM-5.3 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 GLM-5.3

  • overall performance matters — it scores 53.6 and ranks #9 on LLM Stats
  • your work emphasizes reasoning and coding — it leads those capability indexes
  • you value its reported benchmark strengths — it wins 6 of 8 exact shared results
  • you want the most recent training data — it shipped Aug 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.

GLM-5.3
Zhipu AI
Seed 2.1 Pro
ByteDance
Core performance indexes
LLM Stats Score
53.6
#9
46.4
#25
Reasoning
52.9
#6
47.2
#22
Coding
43.0
#6
33.7
#31
Agents
39.5
#7
31.3
#26
Cost, coverage & limits
Benchmark wins
6 of 8
2 of 8
Input price
$1.40 / M
— / M
Output price
$4.40 / M
— / M
Context window
1,000,000
—

Capability indexes

Additional strengths measured across groups of related public benchmarks

1 shared
Index
GLM-5.3
Seed 2.1 Pro
Tool use
33.8#4
26.4#27
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

17 reported for GLM-5.3 · 94 for Seed 2.1 Pro

8 shared

GLM-5.3 outperforms in 6 benchmarks (CyberGym, Humanity's Last Exam, NL2Repo, PostTrainBench, Terminal-Bench 2.1, Toolathlon), while Seed 2.1 Pro is better at 2 benchmarks (Agents' Last Exam, Program Bench).

GLM-5.3 shows notably better performance in the majority of benchmarks.

Sat Sep 05 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-5.3 specifies input context (1,000,000 tokens). Only GLM-5.3 specifies output context (131,072 tokens).

Zhipu AI
GLM-5.3
Input1,000,000 tokens
Output131,072 tokens
ByteDance
Seed 2.1 Pro
Input- tokens
Output- tokens
Sat Sep 05 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Seed 2.1 Pro supports multimodal inputs, whereas GLM-5.3 does not.

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

GLM-5.3

Text
Images
Audio
Video

Seed 2.1 Pro

Text
Images
Audio
Video

License

Usage and distribution terms

GLM-5.3 is licensed under GLM-5.3 License, 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.

GLM-5.3

GLM-5.3 License

Open weights

Seed 2.1 Pro

Proprietary

Closed source

Release Timeline

When each model was launched

GLM-5.3 was released on 2026-08-14, while Seed 2.1 Pro was released on 2026-06-24.

GLM-5.3 is 2 months newer than Seed 2.1 Pro.

GLM-5.3

Aug 14, 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 GLM-5.3 and Seed 2.1 Pro side-by-side, then vote on the output you prefer.

GLM-5.3
✓ Preferred
Seed 2.1 Pro
Open in Playground

FAQ

Common questions about GLM-5.3 vs Seed 2.1 Pro.

Which is better, GLM-5.3 or Seed 2.1 Pro?

GLM-5.3 leads the LLM Stats Score 53.6 to 46.4. GLM-5.3 is made by Zhipu 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 GLM-5.3 compare to Seed 2.1 Pro in benchmarks?

GLM-5.3 scores Terminal-Bench 2.1: 88.2%, CyberGym: 84.5%, FrontierSWE: 78.1%, Toolathlon: 73.0%, DeepSWE 1.1: 66.9%. 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 GLM-5.3 and Seed 2.1 Pro?

GLM-5.3 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 GLM-5.3 and Seed 2.1 Pro?

Key differences include LLM Stats Score (53.6 vs 46.4), multimodal support (no vs yes), licensing (GLM-5.3 License vs Proprietary). See the full comparison above for benchmark-by-benchmark results.

Who makes GLM-5.3 and Seed 2.1 Pro?

GLM-5.3 is developed by Zhipu AI and Seed 2.1 Pro is developed by ByteDance.

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