head-to-head

OpenAI: GPT-5.6 Luna vs Anthropic: Claude Opus 4.8 (batch)

Side-by-side comparison of specs, pricing, benchmark scores, and task rankings. Updated 2026-11-07.

OpenAI: GPT-5.6 Luna Anthropic: Claude Opus 4.8 (batch)
Vendoropenaianthropic
Quality Score100100
Benchmark Score89.493.7
Input Price$0.20/M$2.50/M
Output Price$1.20/M$12.50/M
Context Window1,050,0001,000,000
Max Output128,000128,000
Tool Calling✓✓
Structured Output✓✓
Reasoning Mode✓✓
Vision✓✓
Audio--
Benchmark Scores
ai_index84.591.9
ai_index_agentic75.277.8
ai_index_coding100.0100.0
eqbench-74.2

The verdict

For a sample job of 1 million input tokens and 250,000 output tokens, GPT-5.6 Luna costs $0.50 and Claude Opus 4.8 (batch) costs $5.62, so GPT-5.6 Luna is about 11.2 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 4.8 (batch) leads 93.7 to 89.4.

Across the 20 tasks where they differ, GPT-5.6 Luna scores higher on 4 (Code Completion, JSON Extraction, Bulk Data Labeling and others), Claude Opus 4.8 (batch) on 16 (SQL Generation, Code Review, Code Refactoring and others).

GPT-5.6 Luna was released in July 2026 and Claude Opus 4.8 (batch) in May 2026.

Pick GPT-5.6 Luna if you need lower cost; pick Claude Opus 4.8 (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?

TaskOpenAI: GPT-5.6 LunaAnthropic: Claude Opus 4.8 (batch)
SQL Generation 171 176
Code Review 166 177
Code Completion 133 121
Code Refactoring 163 174
Bug Fixing 179 190
Unit Test Generation 154 160
Code Documentation 143 147
Regex Writing 136 137
CI/CD Pipelines 144 150
Frontend Component Design 146 150
Data Analysis 170 176
CSV / Spreadsheet Cleanup 154 158
ETL Scripting 154 162
JSON Extraction 149 138
Bulk Data Labeling 135 123
OCR / Document Parsing 146 149
Table Extraction from PDFs 146 149
Long-Document Summarization 159 169
Short-Form Summarization 132 123
Blog Post Writing 140 145

Scores reflect capability match + benchmark data + pricing for each task. Methodology →

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