OpenAI: GPT-5.6 Luna Pro (batch) vs SpaceXAI: Grok 4.5
Side-by-side comparison of specs, pricing, benchmark scores, and task rankings. Updated 2026-11-07.
| OpenAI: GPT-5.6 Luna Pro (batch) | SpaceXAI: Grok 4.5 | |
|---|---|---|
| Vendor | openai | x-ai |
| Quality Score | 100 | 100 |
| Benchmark Score | - | 91.2 |
| Input Price | $0.10/M | $2.00/M |
| Output Price | $0.60/M | $6.00/M |
| Context Window | 1,050,000 | 500,000 |
| Max Output | 128,000 | 450,000 |
| Tool Calling | ✓ | ✓ |
| Structured Output | ✓ | ✓ |
| Reasoning Mode | ✓ | ✓ |
| Vision | ✓ | ✓ |
| Audio | - | - |
| Benchmark Scores | ||
| ai_index | - | 88.8 |
| ai_index_agentic | - | 75.4 |
| ai_index_coding | - | 100.0 |
The verdict
For a sample job of 1 million input tokens and 250,000 output tokens, GPT-5.6 Luna Pro (batch) costs $0.25 and Grok 4.5 costs $3.50, so GPT-5.6 Luna Pro (batch) is about 14.0 times cheaper for the same work.
GPT-5.6 Luna Pro (batch) reads up to 1,050,000 tokens at once, roughly 1,575 pages of text, against about 750 pages for Grok 4.5.
Across the 20 tasks where they differ, GPT-5.6 Luna Pro (batch) scores higher on 3 (Code Completion, Bulk Data Labeling, Short-Form Summarization), Grok 4.5 on 17 (SQL Generation, Code Review, Code Refactoring and others).
Pick GPT-5.6 Luna Pro (batch) if you need lower cost or long documents; pick Grok 4.5 if you need 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-5.6 Luna Pro (batch) | SpaceXAI: Grok 4.5 |
|---|---|---|
| SQL Generation | 133 | 171 |
| Code Review | 132 | 167 |
| Code Completion | 131 | 120 |
| Code Refactoring | 136 | 164 |
| Bug Fixing | 136 | 180 |
| Unit Test Generation | 124 | 154 |
| Code Documentation | 131 | 142 |
| Regex Writing | 119 | 135 |
| CI/CD Pipelines | 120 | 144 |
| Frontend Component Design | 122 | 146 |
| Data Analysis | 124 | 170 |
| CSV / Spreadsheet Cleanup | 133 | 154 |
| ETL Scripting | 128 | 154 |
| JSON Extraction | 131 | 139 |
| Bulk Data Labeling | 129 | 125 |
| OCR / Document Parsing | 131 | 146 |
| Table Extraction from PDFs | 131 | 146 |
| Long-Document Summarization | 137 | 159 |
| Short-Form Summarization | 123 | 123 |
| Blog Post Writing | 121 | 140 |
Scores reflect capability match + benchmark data + pricing for each task. Methodology →