OpenAI: GPT-6 Luna vs Anthropic: Claude Opus 5.5 (batch)
Side-by-side comparison of specs, pricing, benchmark scores, and task rankings. Updated 2026-10-13.
| OpenAI: GPT-6 Luna | Anthropic: Claude Opus 5.5 (batch) | |
|---|---|---|
| Vendor | openai | anthropic |
| Quality Score | 100 | 100 |
| Benchmark Score | 63.8 | 100.0 |
| Input Price | $0.10/M | $2.00/M |
| Output Price | $0.50/M | $10.00/M |
| Context Window | 1,050,000 | 1,000,000 |
| Max Output | 128,000 | 128,000 |
| Tool Calling | ✓ | ✓ |
| Structured Output | ✓ | ✓ |
| Reasoning Mode | ✓ | ✓ |
| Vision | ✓ | ✓ |
| Audio | - | - |
| Benchmark Scores | ||
| ai_index | 62.9 | 95.1 |
The verdict
For a sample job of 1 million input tokens and 250,000 output tokens, GPT-6 Luna costs $0.23 and Claude Opus 5.5 (batch) costs $4.50, so GPT-6 Luna is about 20.0 times cheaper for the same work.
Both take in a similar amount of text: 1,050,000 and 1,000,000 tokens, about 1,575 and 1,500 pages.
On our blended benchmark score Claude Opus 5.5 (batch) leads 100.0 to 63.8.
Across the 20 tasks where they differ, GPT-6 Luna scores higher on 4 (Code Completion, JSON Extraction, Bulk Data Labeling and others), Claude Opus 5.5 (batch) on 16 (SQL Generation, Code Review, Code Refactoring and others).
Pick GPT-6 Luna if you need lower cost; pick Claude Opus 5.5 (batch) if you need benchmark performance 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-6 Luna | Anthropic: Claude Opus 5.5 (batch) |
|---|---|---|
| SQL Generation | 141 | 144 |
| Code Review | 144 | 150 |
| Code Completion | 133 | 119 |
| Code Refactoring | 146 | 151 |
| Bug Fixing | 148 | 154 |
| Unit Test Generation | 131 | 135 |
| Code Documentation | 137 | 138 |
| Regex Writing | 126 | 127 |
| CI/CD Pipelines | 127 | 131 |
| Frontend Component Design | 129 | 133 |
| Data Analysis | 133 | 138 |
| CSV / Spreadsheet Cleanup | 136 | 136 |
| ETL Scripting | 136 | 141 |
| JSON Extraction | 131 | 121 |
| Bulk Data Labeling | 129 | 118 |
| OCR / Document Parsing | 134 | 135 |
| Table Extraction from PDFs | 134 | 135 |
| Long-Document Summarization | 148 | 152 |
| Short-Form Summarization | 127 | 118 |
| Blog Post Writing | 129 | 132 |
Scores reflect capability match + benchmark data + pricing for each task. Methodology →