Claude Opus 4.8 vs GPT-5.6 Luna
Claude Opus 4.8 leads in 3 of 8 categories
Arena ELO
Tie
Cheaper
Claude Opus 4.8
Faster
Tie
Detailed Comparison
| Category | Claude Opus 4.8 | GPT-5.6 Luna |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Context Window | 200K WIN | 128K |
| Input Price ($/1M) | $15 WIN | N/A |
| Output Price ($/1M) | $75 WIN | N/A |
| Arena ELO | N/A | N/A |
| Coding | N/A | N/A |
| Reasoning | N/A | N/A |
| Speed (tokens/sec) | N/A | N/A |
| Open Source | No | No |
Frequently Asked Questions
Which has a larger context window?
Claude Opus 4.8 supports 200K context, while GPT-5.6 Luna supports 128K.
Is Claude Opus 4.8 or GPT-5.6 Luna open source?
Claude Opus 4.8 is proprietary. GPT-5.6 Luna is proprietary.
Related Articles
Anthropic’s California deal makes Claude the default public-sector AI
Claude Sonnet 4.6 narrows the SRE gap
GLM 5.2 beats Claude in Semgrep’s IDOR test
Claude Code turns agent setup into terminal work
Anthropic Accuses Alibaba of Massive Claude Distillation
OpenAI narrows GPT-5.6 rollout after U.S. request
More Comparisons
Claude Opus 4.8 vs Claude Opus 4.5Claude Opus 4.8 vs Llama 4 ScoutClaude Opus 4.8 vs Claude Sonnet 4.6Claude Opus 4.8 vs Claude Haiku 4.5Claude Opus 4.8 vs GLM-5.2Claude Opus 4.8 vs Qwen 3.6Claude Opus 4.8 vs Claude Fable 5Claude Opus 4.8 vs Kimi K2.7 CodeGPT-5.6 Luna vs Claude Opus 4.5GPT-5.6 Luna vs Llama 4 ScoutGPT-5.6 Luna vs Claude Sonnet 4.6GPT-5.6 Luna vs Claude Haiku 4.5GPT-5.6 Luna vs GLM-5.2GPT-5.6 Luna vs Qwen 3.6GPT-5.6 Luna vs Claude Fable 5GPT-5.6 Luna vs Kimi K2.7 Code