Z.ai: GLM 5.3 Flash vs OpenAI: GPT-5.6 Sol
Side-by-side comparison of specs, pricing, benchmark scores, and task rankings. Updated 2026-10-11.
| Z.ai: GLM 5.3 Flash | OpenAI: GPT-5.6 Sol | |
|---|---|---|
| Vendor | z-ai | openai |
| Quality Score | 100 | 100 |
| Benchmark Score | 70.6 | 80.2 |
| Input Price | $0.15/M | $2.00/M |
| Output Price | $0.50/M | $10.00/M |
| Context Window | 1,048,576 | 1,050,000 |
| Max Output | 943,717 | 128,000 |
| Tool Calling | ✓ | ✓ |
| Structured Output | ✓ | ✓ |
| Reasoning Mode | ✓ | ✓ |
| Vision | ✓ | ✓ |
| Audio | - | - |
| Benchmark Scores | ||
| ai_index | 69.0 | 77.5 |
The verdict
For a sample job of 1 million input tokens and 250,000 output tokens, GLM 5.3 Flash costs $0.28 and GPT-5.6 Sol costs $4.50, so GLM 5.3 Flash is about 16.4 times cheaper for the same work.
Both take in a similar amount of text: 1,048,576 and 1,050,000 tokens, about 1,573 and 1,575 pages.
Only GLM 5.3 Flash offers video input.
On our blended benchmark score GPT-5.6 Sol leads 80.2 to 70.6.
Across the 20 tasks where they differ, GLM 5.3 Flash scores higher on 9 (SQL Generation, Code Completion, Code Documentation and others), GPT-5.6 Sol on 11 (Code Review, Code Refactoring, Bug Fixing and others).
GLM 5.3 Flash was released in August 2026 and GPT-5.6 Sol in July 2026.
Pick GLM 5.3 Flash if you need lower cost or video input; pick GPT-5.6 Sol 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 | OpenAI: GPT-5.6 Sol |
|---|---|---|
| SQL Generation | 142 | 142 |
| Code Review | 145 | 146 |
| Code Completion | 133 | 119 |
| Code Refactoring | 147 | 148 |
| Bug Fixing | 149 | 150 |
| Unit Test Generation | 132 | 133 |
| Code Documentation | 138 | 136 |
| Regex Writing | 126 | 125 |
| CI/CD Pipelines | 128 | 129 |
| Frontend Component Design | 130 | 131 |
| Data Analysis | 134 | 135 |
| CSV / Spreadsheet Cleanup | 136 | 135 |
| ETL Scripting | 137 | 138 |
| JSON Extraction | 131 | 121 |
| Bulk Data Labeling | 129 | 118 |
| OCR / Document Parsing | 134 | 134 |
| Table Extraction from PDFs | 134 | 134 |
| Long-Document Summarization | 149 | 149 |
| Short-Form Summarization | 127 | 117 |
| Blog Post Writing | 130 | 130 |
Scores reflect capability match + benchmark data + pricing for each task. Methodology →