Guide

LLM Cost Optimization

Strategies to reduce LLM costs without sacrificing quality or safety.

· 8 min read

LLM costs can spiral quickly in production. Token-based pricing means every prompt and response has a cost. Here's how to optimize spending while maintaining quality.

Understanding LLM Costs

LLM pricing is typically based on:

  • Input tokens: Your prompts, context, and system instructions
  • Output tokens: Model responses
  • Model tier: GPT-4 costs 10-30x more than GPT-3.5

Cost Optimization Strategies

1. Right-Size Your Model

Not every task needs GPT-4. Use smaller models for simple tasks:

  • Classification and routing: GPT-3.5 or smaller
  • Simple Q&A: Fine-tuned smaller models
  • Complex reasoning: GPT-4 or Claude

2. Optimize Prompts

  • Remove unnecessary context and instructions
  • Use concise system prompts
  • Limit few-shot examples to minimum needed

3. Implement Caching

  • Cache responses for identical or similar queries
  • Use semantic caching for near-duplicate requests
  • Cache embeddings for RAG applications

4. Limit Output Length

  • Set max_tokens appropriately for each use case
  • Instruct models to be concise
  • Use structured output formats

Cost Monitoring

Track costs to identify optimization opportunities:

  • Monitor token usage per endpoint
  • Track cost per user or feature
  • Set alerts for spending anomalies
  • Review high-cost queries for optimization

DriftRail Cost Tracking

DriftRail captures token usage for cost analysis:

await client.ingest({
  model: 'gpt-4',
  provider: 'openai',
  metadata: {
    tokensIn: 500,
    tokensOut: 200,
    latencyMs: 850
  }
});

The dashboard shows token usage trends, helping identify cost optimization opportunities.

FAQ

How much can I save with optimization?

Teams typically reduce LLM costs 40-70% through model selection, prompt optimization, and caching. The biggest savings come from using smaller models where appropriate.

Does cost optimization affect quality?

Not necessarily. Many tasks don't require the most powerful models. The key is matching model capability to task complexity. Monitor quality metrics alongside costs.

Track LLM costs and quality

Monitor token usage and safety metrics with DriftRail.

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