Z.ai: GLM 5.3 Flash vs MoonshotAI: Kimi K3
Side-by-side comparison of specs, pricing, benchmark scores, and task rankings. Updated 2026-10-11.
| Z.ai: GLM 5.3 Flash | MoonshotAI: Kimi K3 | |
|---|---|---|
| Vendor | z-ai | moonshotai |
| Quality Score | 100 | 100 |
| Benchmark Score | 70.6 | 73.9 |
| Input Price | $0.15/M | $0.80/M |
| Output Price | $0.50/M | $12.00/M |
| Context Window | 1,048,576 | 1,048,576 |
| Max Output | 943,717 | 943,718 |
| Tool Calling | ✓ | ✓ |
| Structured Output | ✓ | ✓ |
| Reasoning Mode | ✓ | ✓ |
| Vision | ✓ | ✓ |
| Audio | - | - |
| Benchmark Scores | ||
| ai_index | 69.0 | 71.9 |
The verdict
For a sample job of 1 million input tokens and 250,000 output tokens, GLM 5.3 Flash costs $0.28 and Kimi K3 costs $3.80, so GLM 5.3 Flash is about 13.8 times cheaper for the same work.
Both read up to 1,048,576 tokens at once, roughly 1,573 pages of text.
On our blended benchmark score Kimi K3 leads 73.9 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), Kimi K3 on 10 (Code Review, Code Refactoring, Bug Fixing and others).
GLM 5.3 Flash was released in August 2026 and Kimi K3 in July 2026.
Pick GLM 5.3 Flash if you need lower cost; pick Kimi K3 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?
| Task | Z.ai: GLM 5.3 Flash | MoonshotAI: Kimi K3 |
|---|---|---|
| SQL Generation | 142 | 141 |
| Code Review | 145 | 145 |
| Code Completion | 133 | 130 |
| Code Refactoring | 147 | 147 |
| Bug Fixing | 149 | 149 |
| Unit Test Generation | 132 | 132 |
| Code Documentation | 138 | 135 |
| Regex Writing | 126 | 124 |
| CI/CD Pipelines | 128 | 128 |
| Frontend Component Design | 130 | 130 |
| Data Analysis | 134 | 134 |
| CSV / Spreadsheet Cleanup | 136 | 135 |
| ETL Scripting | 137 | 138 |
| JSON Extraction | 131 | 129 |
| Bulk Data Labeling | 129 | 126 |
| OCR / Document Parsing | 134 | 134 |
| Table Extraction from PDFs | 134 | 134 |
| Long-Document Summarization | 149 | 148 |
| Short-Form Summarization | 127 | 125 |
| Blog Post Writing | 130 | 129 |
Scores reflect capability match + benchmark data + pricing for each task. Methodology →