OpenAI: GPT Luna Latest vs Z.ai: GLM 5.3 Flash
Side-by-side comparison of specs, pricing, benchmark scores, and task rankings. Updated 2026-11-07.
| OpenAI: GPT Luna Latest | Z.ai: GLM 5.3 Flash | |
|---|---|---|
| Vendor | ~openai | z-ai |
| Quality Score | 100 | 100 |
| Input Price | $0.10/M | $0.03/M |
| Output Price | $0.50/M | $0.08/M |
| Context Window | 1,050,000 | 1,048,576 |
| Max Output | 128,000 | 131,072 |
| Tool Calling | ✓ | ✓ |
| Structured Output | ✓ | ✓ |
| Reasoning Mode | ✓ | ✓ |
| Vision | ✓ | ✓ |
| Audio | - | - |
The verdict
For a sample job of 1 million input tokens and 250,000 output tokens, GLM 5.3 Flash costs $0.054 and GPT Luna Latest costs $0.23, so GLM 5.3 Flash is about 4.1 times cheaper for the same work.
Both take in a similar amount of text: 1,050,000 and 1,048,576 tokens, about 1,575 and 1,573 pages.
Only GLM 5.3 Flash offers video input.
Across the 10 tasks where they differ, GLM 5.3 Flash on 10 (SQL Generation, Code Completion, Code Documentation and others).
GPT Luna Latest was released in September 2026 and GLM 5.3 Flash in August 2026.
Pick GLM 5.3 Flash if you need lower cost, video input or the stronger all-round task scores.
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 | OpenAI: GPT Luna Latest | Z.ai: GLM 5.3 Flash |
|---|---|---|
| SQL Generation | 133 | 134 |
| Code Completion | 131 | 132 |
| Code Documentation | 131 | 132 |
| Regex Writing | 119 | 120 |
| CSV / Spreadsheet Cleanup | 133 | 134 |
| JSON Extraction | 131 | 132 |
| Bulk Data Labeling | 129 | 130 |
| Long-Document Summarization | 137 | 138 |
| Short-Form Summarization | 123 | 124 |
| Blog Post Writing | 121 | 122 |
Scores reflect capability match + benchmark data + pricing for each task. Methodology →