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GLM-5.3 vs Grok-4 Heavy

GLM-5.3 significantly outperforms across most benchmarks.

Zhipu AI · xAI · Updated for 2026

Which is better?

GLM-5.3 outperforms in 1 benchmarks (Humanity's Last Exam), while Grok-4 Heavy is better at 0 benchmarks. GLM-5.3 significantly outperforms across most benchmarks.

Based on current benchmark, pricing, and model metadata for 2026.

Choose GLM-5.3

  • you want the strongest raw capability — it leads on 1 of 1 shared benchmarks

Choose Grok-4 Heavy

  • you are already invested in the xAI ecosystem

At a glance

The differences that matter most.

GLM-5.3
Zhipu AI
Grok-4 Heavy
xAI
Benchmark wins
1 of 1
0 of 1
Input price
$1.40 / M
— / M
Output price
$4.40 / M
— / M
Context window
1,000,000
—
Released
Aug 2026
—
License
Unknown
Proprietary

Performance Benchmarks

Comparative analysis across standard metrics

1 benchmarks

GLM-5.3 outperforms in 1 benchmarks (Humanity's Last Exam), while Grok-4 Heavy is better at 0 benchmarks.

GLM-5.3 significantly outperforms across most benchmarks.

Tue Aug 25 2026 • llm-stats.com

Arena Performance

Playground indexes and blind 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 (128,000 tokens).

Zhipu AI
GLM-5.3
Input1,000,000 tokens
Output128,000 tokens
xAI
Grok-4 Heavy
Input- tokens
Output- tokens
Tue Aug 25 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Grok-4 Heavy supports multimodal inputs, whereas GLM-5.3 does not.

Grok-4 Heavy can handle both text and other forms of data like images, making it suitable for multimodal applications.

GLM-5.3

Text
Images
Audio
Video

Grok-4 Heavy

Text
Images
Audio
Video

Release Timeline

When each model was launched

GLM-5.3 was released on 2026-08-14, while Grok-4 Heavy's release date is not specified.

We can confirm GLM-5.3's release timeline, but cannot make a direct age comparison without Grok-4 Heavy's release date.

GLM-5.3

Aug 14, 2026

1 weeks ago

Grok-4 Heavy

—

Knowledge Cutoff

When training data ends

Grok-4 Heavy has a documented knowledge cutoff of 2024-12-31, while GLM-5.3's cutoff date is not specified.

We can confirm Grok-4 Heavy's training data extends to 2024-12-31, but cannot make a direct comparison without GLM-5.3's cutoff date.

GLM-5.3

—

Grok-4 Heavy

Dec 2024

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Judge for yourself.

Run your own prompts against GLM-5.3 and Grok-4 Heavy side-by-side, then vote on the output you prefer.

GLM-5.3
✓ Preferred
Grok-4 Heavy
Open in Playground

FAQ

Common questions about GLM-5.3 vs Grok-4 Heavy.

Which is better, GLM-5.3 or Grok-4 Heavy?

GLM-5.3 significantly outperforms across most benchmarks. GLM-5.3 is made by Zhipu AI and Grok-4 Heavy is made by xAI. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does GLM-5.3 compare to Grok-4 Heavy 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%. Grok-4 Heavy scores AIME 2025: 100.0%, HMMT25: 96.7%, GPQA: 88.4%, LiveCodeBench: 79.4%, USAMO25: 61.9%.

What are the context window sizes for GLM-5.3 and Grok-4 Heavy?

GLM-5.3 supports 1.0M tokens and Grok-4 Heavy 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 Grok-4 Heavy?

Key differences include multimodal support (no vs yes), licensing (Unknown vs Proprietary). See the full comparison above for benchmark-by-benchmark results.

Who makes GLM-5.3 and Grok-4 Heavy?

GLM-5.3 is developed by Zhipu AI and Grok-4 Heavy is developed by xAI.

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