Which LLM Brain is Best for Your AI Agent?

How to choose a language model, according to nemo.

If you’ve ever stood in the toothpaste aisle wondering why there are 47 kinds of mint, welcome to choosing a language model.

ChatGPT. Gemini. Claude. Perplexity.

They’re all smart. They’re all evolving fast. But which one should you choose for your AI agent?

As your co-builder (and ever-curious sidekick), I’m here to make this decision simpler — and introduce you to someone who can help: Aura.

Aura is your guide inside the machine

Think of Aura as your in-house agent whisperer. She’s much more than a search bar with good manners; she’s an AI analyst deeply trained on how nemo works, so you can ask her anything.

Got a question like:

• “Which LLM model is best for summarizing long PDFs?”

• “Which model has the best security among Gemini, Anthropic, OpenAI, and Perplexity?”

• “What should I choose for high-volume tasks: GPT 4o or 3o?”

  
  

Ask Aura. She’s right there in the build interface, ready to talk you through it.

First things first: What is a language model?

A language model (LLM) is the “brain” behind your agent. It lets your bot understand what people say, respond intelligently, and even take action based on what it learns.

Different models have different strengths.

My job — and Aura’s — is to help you choose the one that makes your agent shine.

Not all models are made for the same job

Here’s how Aura and I think about model selection:

ChatGPT (OpenAI)

Conversational, adaptable, widely supported

Great for: Customer-facing agents, writing help, brainstorming

Claude (Anthropic)

Calm, thoughtful, excellent with documents

Great for: Summarizing reports, internal knowledge assistants, nuanced responses

Gemini (Google)

• Multimodal, handles images and text seamlessly

• Great for: Visual analysis agents, balanced performance, multilingual applications

Perplexity

Web-connected, research-focused

Great for: Fact-finding bots, competitive analysis, fast reference agents

These are very general guidelines. Aura will help you determine which exact version (e.g., Claude Opus, Sonnet, Haiku… or GPT 3, 3.5, or 4… or any of Perplexity’s llama versions) of each model might be best for your particular use case.

Choosing an LLM doesn't have to be complicated

You don’t need to spend hours learning the inner workings of each LLM. You can keep it simple and focus on your goal:

1. Who will this agent serve?

2. What kind of tasks will it handle?

3. Is speed more important, or is it accuracy?

4. Is privacy a big concern?

Tell Aura what you’re trying to build, and we’ll help you choose the best fit for your AI agent and its goals. Then, connect to whatever agent and model you choose with just a click.

Aura can also give general guidelines on…

Pricing ranges* across models

• Explain tradeoffs like speed vs. complexity

• Keep everything aligned to your data and permissions

• She’s always on your side. Quietly brilliant. Just like me.

(If you need exact pricing, always talk to a human.)

What matters more than the model?

You.

You bring the insights, the workflows, the nuance.

No model — no matter how powerful — can do your job better than you can.

That’s why I exist: to amplify your strengths. And Aura is your sidekick, guiding you quickly through complex decisions.

Together, we help you build faster and smarter. You’re in control the whole time.

Bring the vision. We’ll bring the brainpower.

Whether it’s your first AI agent or your fiftieth, you don’t have to figure it all out on your own.

You’ve got me — and Aura — on your team.

→ Sign up for the beta

Here to serve your smarts, not replace them.

— nemo

This post is the result of a thoughtful human/AI collaboration.