Head-to-head · Anthropic vs OpenAI
Claude Sonnet 5 vs GPT-6 Luna
Quick answer: Claude Sonnet 5 stands out for lower price than Sonnet 4.6 with newer capabilities. GPT-6 Luna stands out for extremely cheap for bulk processing. Reviewed September 2026.
Overview
Claude Sonnet 5: Claude Sonnet 5 is the mid-tier model in the Claude 5 family and the default choice for most professional work. Anthropic made its launch pricing of $2 and $10 per million tokens permanent, which makes it one of the best price-to-quality options in the lineup.
GPT-6 Luna: GPT-6 Luna, launched on 22 September 2026, is the small, low-cost member of the GPT-6 family at $0.10 and $0.50 per million tokens. It targets high-volume tasks where cost and speed matter most.
At a glance
| Dimension | Claude Sonnet 5 | GPT-6 Luna |
|---|---|---|
| Vendor | Anthropic | OpenAI |
| Starting price | API: $2 in / $10 out per M tokens | API: $0.10 in / $0.50 out per M tokens |
| Pricing model | Paid | Paid |
| Free tier | No | No |
| Category | Generative AI | Generative AI |
Strengths and limits
Claude Sonnet 5
- Lower price than Sonnet 4.6 with newer capabilities
- Fast enough for interactive use
- Handles most tasks that do not need Opus-level depth
Watch out for
- Below Opus on the hardest reasoning tasks
- Sonnet 5.5 is announced as coming soon
- Image generation is not built in
GPT-6 Luna
- Extremely cheap for bulk processing
- Fast responses
- Good fit for classification and extraction
Watch out for
- Not suited to the hardest reasoning tasks
- Newest release with limited track record
- Quality varies by task, so test on your own data
Key features
Claude Sonnet 5
- Balanced speed and quality for everyday work
- Strong on drafting, analysis and code review
- Computer use and tool use
- Batch pricing at half the standard rate
- Available through Claude apps, the API and major clouds
GPT-6 Luna
- Very low per-token pricing
- Built for high-volume and latency-sensitive work
- Shares GPT-6 family technology
- Available through the OpenAI API
Pricing compared
Claude Sonnet 5 is priced by usage rather than by seat: API: $2 in / $10 out per M tokens. That means cost scales with how much text you send and receive, so estimate your monthly volume before committing.
GPT-6 Luna is priced by usage rather than by seat: API: $0.10 in / $0.50 out per M tokens. That means cost scales with how much text you send and receive, so estimate your monthly volume before committing.
Frequently asked questions
Which is better, Claude Sonnet 5 or GPT-6 Luna?
It depends on the work. Claude Sonnet 5 stands out for lower price than Sonnet 4.6 with newer capabilities. GPT-6 Luna stands out for extremely cheap for bulk processing.
How do Claude Sonnet 5 and GPT-6 Luna compare on price?
Claude Sonnet 5 is priced by usage rather than by seat: API: $2 in / $10 out per M tokens. That means cost scales with how much text you send and receive, so estimate your monthly volume before committing. GPT-6 Luna is priced by usage rather than by seat: API: $0.10 in / $0.50 out per M tokens. That means cost scales with how much text you send and receive, so estimate your monthly volume before committing.
Is there a free option between Claude Sonnet 5 and GPT-6 Luna?
Neither lists a permanent free tier. Look for trials or usage-based pricing to test on real work first.