DEV Community

Asmae Elazrak for cortecs

Posted on • Edited on

Comparing LLM Routers

Large Language Models (LLMs) are rapidly reshaping the tech landscape, transforming industries from AI-powered assistants and summarization tools to smart customer support and beyond.

In today’s fast-moving AI world, developers need access to multiple models from different providers to serve diverse use cases.

The challenge isn’t just which model to use, it’s:

How do you balance reliability, cost, speed, and data privacy while using LLMs, without becoming an infrastructure engineer❓

At the heart of this problem lies the LLM router.

Image illustrating how an LLM router directs requests to multiple AI model providers


📦 What is an LLM Router?

An LLM router is like a smart traffic controller between your application and various LLM providers.

It helps decide:

  • Which model should handle each request
  • How to handle provider failures or slow responses
  • How to balance cost, speed, reliability, and compliance across providers

At a high level, an LLM router:

  • Accepts your inference request (like a chat prompt or code generation task)
  • Evaluates available LLM providers (OpenAI, Anthropic, Nebius, etc.)
  • Chooses the best provider based on real-time factors like cost, latency, and reliability
  • Sends the request to the selected provider and returns the response

Think of it as a smart, adaptable dispatcher that shields you from the complexity of managing multiple LLM APIs.


⚙️ Why Do You Need an LLM Router?

Without a router, you’re typically tied to a single provider, which brings several risks:

  • Vendor Lock-in: If your provider increases prices, rate limits you, or experiences downtime, you have limited options.
  • Missed Savings: Some providers offer similar quality at significantly lower costs.
  • Limited Model Specialization: Some models are better suited for code, others for summarization, chat, or creative tasks.
  • Data Privacy and Compliance Risks: Using non-compliant providers, especially in the EU, can lead to GDPR violations and legal issues.
  • Limited Model Choice: Relying on a single provider restricts your access to the growing variety of models available across the ecosystem.

With an LLM router, you can:

  • Load-balance across multiple providers
  • Failover automatically when a provider is unavailable
  • Optimize for cost, latency, and privacy in real time
  • Leverage model diversity for specialized tasks

💡 Bottom line: If you want to deliver fast, cost-efficient, reliable, and compliant AI experiences at scale, an LLM router is no longer optional.


🧐 Comparison

Let’s break down noteworthy LLM routers:


1️⃣ Cortecs

Cortecs Landing page screenshot

Pros:

  • Compliant with European GDPR.
  • Best coverage of the European ecosystem.
  • Automated failover.

Cons:

  • Focused on Europe and GDPR.

2️⃣ Withmartian

Pros:

  • Dynamically routes requests to the best-performing model for each specific query.
  • Offers significant cost savings by routing to cheaper models.
  • Outperforms even GPT-4 on OpenAI’s own evaluations.

Cons:

  • Pricing can be complex, with potential cost increases for advanced features or large-scale usage.
  • Usage in Europe may require GDPR compliance considerations.

3️⃣ Requesty

Pros:

  • Supports a wide range of providers through a single API key.
  • Provides detailed information to improve observability and cost tracking.
  • Offers cost savings through efficient request management.

Cons:

  • Smart routing classification model can be complex to configure initially.
  • Latency overhead from the classification model may impact ultra-low-latency applications.
  • Usage in Europe may require GDPR compliance considerations.

4️⃣ NotDiamond

Pros:

  • Uses a Random Forest Classifier to intelligently route prompts to the most suitable model.
  • Allows tuning of the cost-performance tradeoff through a threshold parameter.
  • Supports training custom routers for hyper-personalized routing tailored to specific applications.

Cons:

  • Custom router training can be complex to set up.
  • Limited public documentation on pricing, which may complicate budgeting.
  • Usage in Europe may require GDPR compliance considerations.

5️⃣ OpenRouter

OpenRouter playground screenshot

Pros:

  • Provides a unified API to access multiple LLM providers.
  • Supports a wide range of models from various providers.
  • Offers higher availability with fallback options.

Cons:

  • Some concerns around data privacy and ownership of user-provided information.
  • Usage in Europe may require GDPR compliance considerations.

If you’re looking for a seamless way to optimize cost, speed, and compliance without getting buried in infrastructure, a LLM Router is a must-have.

🚀 Make your LLM workflows faster, safer, and smarter from day one.

Top comments (1)

Collapse
 
huggyfee profile image
Simon Huggins

I’m not sure the GDPR thing is entirely true unless you are sharing confidential / sensitive data eg Personally Identifiable information. For general purpose use most of these are fine. You just have to be careful about the data you are passing to them.