GPT-3.5 Turbo vs GPT-5.6 Luna Pro
How do these models stack up? Below is an expert side-by-side comparison of specifications, context window capacity, live pricing per million tokens, and standardized benchmark scores for GPT-3.5 Turbo and GPT-5.6 Luna Pro.
GPT-3.5 Turbo
GPT-3.5 Turbo is OpenAI's fastest model. It can understand and generate natural language or code, and is optimized for chat and traditional completion tasks. Training data up to Sep 2021.
GPT-5.6 Luna Pro
GPT-5.6 Luna Pro is the same underlying model as [GPT-5.6 Luna](https://openrouter.ai/openai/gpt-5.6-luna), served with `reasoning.mode` set to `pro` for higher-quality responses on complex tasks. Learn more in OpenAI's docs: https://developers.openai.com/api/docs/guides/reasoning#reasoning-mode
Technical Specifications
| Specification | GPT-3.5 Turbo | GPT-5.6 Luna Pro |
|---|---|---|
| Provider | OpenAI | OpenAI |
| Context Window | 16,385 tokens | 1,050,000 tokens |
| Agent Suitability | N/A | N/A |
| Time to First Token (TTFT) | N/A | N/A |
| Deployment Model | managed api | managed api |
| Production Stability | stable | beta |
| API Available | Yes | Yes |
| Released Date | 2023-05-28 | 2026-07-09 |
API Pricing Comparison
Input Price per Million Tokens
GPT-3.5 Turbo
$0.50
GPT-5.6 Luna Pro
$1.00
Output Price per Million Tokens
GPT-3.5 Turbo
$1.50
GPT-5.6 Luna Pro
$6.00
Want to test both models live?
Run side-by-side prompt prompts in our dynamic Sandbox. Check execution speeds, latency metrics, and compute actual costs in real-time.
Benchmark Performance Metrics
Scores show the raw performance percentages verified across key evaluation suites. Higher bars indicate superior accuracy and capability in that domain.
GPT-3.5 Turbo Quirks & Gotchas
No developer gotchas reported.
GPT-5.6 Luna Pro Quirks & Gotchas
No developer gotchas reported.