Looking for something different?
Models that trade off differently against the one you are viewing
Better quality
Newer flagship models that generally produce stronger results.
Lower cost per run
Open-source models we host, unlimited on the $149/month plan.
Related Models
Discover similar models you might be interested in
About GPT 5.1
Smarter and faster large language model with adaptive reasoning, 128K token context window, dual-mode processing for speed or depth, enhanced coding, and customizable tones.
Technical Specifications
- Model ID
- gpt5.1
- Category
- LLM Models
- Task
- Text Generation
- Price
- $5.63 per million tokens
- Added
- November 16, 2025
Key Features
- Chat completion and multi-turn conversation API
- Streaming response with token-by-token output
- Function calling and tool use support
- System prompts and role-based messaging
- JSON mode and structured output
Quick Start
Integrate GPT 5.1 into your application with a single API call. Get your API key from the pricing page to get started.
import requestsimport jsonurl = "https://modelslab.com/api/v7/llm/chat/completions"headers = {"Content-Type": "application/json"}data = {"model_id": "gpt5.1","messages": [{"role": "user","content": "Hello!"}],"max_tokens": 1000,"key": "YOUR_API_KEY"}try:response = requests.post(url, headers=headers, json=data)response.raise_for_status() # Raises an HTTPError for bad responses (4XX or 5XX)result = response.json()print("API Response:")print(json.dumps(result, indent=2))except requests.exceptions.HTTPError as http_err:print(f"HTTP error occurred: {http_err} - {response.text}")except Exception as err:print(f"Other error occurred: {err}")
Pricing
GPT 5.1 API costs $5.63 per million tokens. Pay only for what you use with no minimum commitments. View pricing plans
Use Cases
- AI chatbots and virtual assistants
- Code generation and developer tools
- Content writing and copywriting automation
- Data analysis, summarization, and extraction
GPT 5.1 FAQ
Smarter and faster large language model with adaptive reasoning, 128K token context window, dual-mode processing for speed or depth, enhanced coding, and customizable tones.
You can integrate GPT 5.1 into your application with a single API call. Sign up on ModelsLab to get your API key, then use the model ID "gpt5.1" in your API requests. We provide SDKs for Python, JavaScript, and cURL examples in the API documentation.
GPT 5.1 costs $5.63 per million tokens. ModelsLab plans start at $21/month (Basic), and the $149/month Open Source plan includes unlimited generation on open-source models.
The model ID for GPT 5.1 is "gpt5.1". Use this ID in your API requests to specify this model.
Yes. ModelsLab is subscription-based with no free tier — plans start at $21/month (Basic, 3,250 API calls). The $149/month Open Source Unlimited plan includes unlimited generation across open-source models; premium third-party models are billed per call from your wallet.