Now that you understand the value of starting with pre-trained models, the next step is figuring out where to find them and how to choose one to experiment with. The good news is that there are many options available, ranging from simple web interfaces to more complex developer platforms. For a beginner, the best place to start is usually a service that makes interaction straightforward.

Where Can You Find LLM Services?

Several types of platforms provide access to pre-trained Large Language Models. Here's a look at the common categories:

Direct Model Provider Platforms: Many organizations that develop LLMs offer their own platforms. These often include user-friendly web interfaces, sometimes called "playgrounds" or "studios," where you can type prompts and see results directly in your browser without writing any code. Examples include OpenAI's Platform (which provides access to models like GPT-4), Google AI Studio (for Gemini models), Anthropic's Console (for Claude models), and Cohere's Platform. These are excellent starting points because they are designed for exploration and often have generous free tiers or initial credits for new users.
Major Cloud Providers: Companies like Amazon Web Services (AWS), Google Cloud Platform (GCP), and Microsoft Azure offer access to a variety of LLMs (including their own and third-party models) through services like AWS Bedrock, Google Vertex AI, and Azure AI Services (including Azure OpenAI). While powerful and scalable, these platforms are generally geared more towards developers building applications and might involve a slightly steeper learning curve initially compared to direct provider playgrounds. However, they are significant platforms in the industry.
Model Hubs: Platforms like Hugging Face serve as central repositories for thousands of pre-trained models, including many open-access models. Hugging Face not only lists models but also often provides tools, datasets, and even hosted "Spaces" or "Inference Endpoints" where you can try models out, sometimes directly in the browser or via simple API calls. It's a valuable resource for exploring a wider range of models beyond those offered by the largest providers.
Consumer Applications: You've likely encountered LLMs through popular applications like ChatGPT, Google Gemini (the web app), or Claude's web interface. While these are primarily end-user applications, interacting with them is a great way to get a feel for what LLMs can do. Keep in mind that using the consumer application is different from using the underlying model service via an Application Programming Interface (API), which offers more control and is the focus when building applications.

How to Choose a Service: Factors for Beginners

With several options available, how do you pick one to start with? Here are some factors to consider, keeping in mind that you're just beginning:

Ease of Use: Prioritize platforms with clear web interfaces (playgrounds). How simple is the sign-up process? Can you start experimenting within minutes without needing to configure complex settings or provide payment information upfront? Good documentation and tutorials aimed at beginners are also helpful.
Cost: Look for services offering free trials, initial credits, or ongoing free tiers suitable for basic experimentation. Most services operate on a pay-as-you-go basis, often charging based on the amount of text processed (measured in tokens, which we discussed in Chapter 2). Understand the pricing model before committing to significant usage, but for initial learning, focus on free options.
Model Availability: Does the platform offer access to models known for being capable and suitable for general tasks? As a beginner, you'll likely want a versatile instruction-following or chat model. The distinctions between general-purpose and specialized models, or open versus closed models (covered in Chapter 4), might influence your choice as you learn more, but start with accessibility.
Learning Resources: Check if the platform provides tutorials, guides, or examples specifically for beginners. Active community forums can also be a source of help.

A Recommended Approach for Getting Started

Don't feel pressured to choose the "perfect" platform immediately. The goal at this stage is exploration and learning.

Start with a Playground: Begin with a service that offers a web-based playground. This allows you to focus on crafting prompts (as covered in Chapter 3) and understanding model behavior without worrying about code.
Utilize Free Tiers: Take advantage of free credits or tiers to experiment without financial commitment. Pay attention to any usage limits associated with these free options.
Pick One or Two: Avoid overwhelming yourself. Select one or perhaps two platforms that seem easy to access and start there. You can always explore others later as your understanding grows.
Focus on Interaction: The next sections will guide you through using these web interfaces and making your first basic API calls. Concentrate on understanding that interaction process first.

Finding the right service is less about a single best choice and more about finding a comfortable environment where you can start learning by doing. The skills you develop in prompting and understanding model responses on one platform are largely transferable to others.