head-to-head

Z.ai: GLM 5.3 Flash vs SpaceXAI: Grok 4.6

Side-by-side comparison of specs, pricing, benchmark scores, and task rankings. Updated 2026-10-11.

Z.ai: GLM 5.3 Flash SpaceXAI: Grok 4.6
Vendorz-aix-ai
Quality Score100100
Benchmark Score70.675.3
Input Price$0.15/M$2.00/M
Output Price$0.50/M$6.00/M
Context Window1,048,576500,000
Max Output943,717450,000
Tool Calling✓✓
Structured Output✓✓
Reasoning Mode✓✓
Vision✓✓
Audio--
Benchmark Scores
ai_index69.073.1

The verdict

For a sample job of 1 million input tokens and 250,000 output tokens, GLM 5.3 Flash costs $0.28 and Grok 4.6 costs $3.50, so GLM 5.3 Flash is about 12.7 times cheaper for the same work.

GLM 5.3 Flash reads up to 1,048,576 tokens at once, roughly 1,573 pages of text, against about 750 pages for Grok 4.6.

Only GLM 5.3 Flash offers video input.

On our blended benchmark score Grok 4.6 leads 75.3 to 70.6.

Across the 20 tasks where they differ, GLM 5.3 Flash scores higher on 10 (SQL Generation, Code Completion, Code Documentation and others), Grok 4.6 on 10 (Code Review, Code Refactoring, Bug Fixing and others).

Pick GLM 5.3 Flash if you need lower cost, long documents or video input; pick Grok 4.6 if you need benchmark performance.

Costs use current list prices per million tokens; page counts assume about 0.75 words per token and 500 words per page.

Who wins by task?

TaskZ.ai: GLM 5.3 FlashSpaceXAI: Grok 4.6
SQL Generation 142 142
Code Review 145 145
Code Completion 133 119
Code Refactoring 147 147
Bug Fixing 149 149
Unit Test Generation 132 132
Code Documentation 138 137
Regex Writing 126 125
CI/CD Pipelines 128 128
Frontend Component Design 130 130
Data Analysis 134 135
CSV / Spreadsheet Cleanup 136 136
ETL Scripting 137 138
JSON Extraction 131 122
Bulk Data Labeling 129 119
OCR / Document Parsing 134 134
Table Extraction from PDFs 134 134
Long-Document Summarization 149 148
Short-Form Summarization 127 118
Blog Post Writing 130 130

Scores reflect capability match + benchmark data + pricing for each task. Methodology →

Related comparisons

Anthropic: Claude Opus 5.5 (batch) vs Z.ai: GLM 5.3 Flash Anthropic: Claude Sonnet 5.5 (batch) vs Z.ai: GLM 5.3 Flash Anthropic: Claude Sonnet 5.5 vs Z.ai: GLM 5.3 Flash ByteDance Seed: Seed-2.0-Code vs SpaceXAI: Grok 4.6 ByteDance Seed: Seed 2.1 Turbo vs SpaceXAI: Grok 4.6 Cohere: Command A+ vs Z.ai: GLM 5.3 Flash DeepSeek: DeepSeek Flash Latest vs SpaceXAI: Grok 4.6 DeepSeek: DeepSeek Flash Latest vs Z.ai: GLM 5.3 Flash

The Model Movers Report

One email every Friday, built from this site's own rankings: the current top five by benchmark score, every model released in the last seven days, and one note worked out from that week's numbers. You can unsubscribe from any issue with one click.