Choosing a model

Select the right AI model for your use case based on performance, cost, and capabilities

Selecting the right model depends on your specific needs. Consider these factors when choosing:

• Task complexity: How sophisticated does the reasoning need to be?
• Response speed: How quickly do you need results?
• Cost constraints: What’s your budget for API calls?
• Context requirements: How much input data do you need to process?
• Special features: Do you need vision, extended thinking, or other capabilities?

Decision Framework

Start with Your Use Case

Real-time Chat Applications

Recommended: Claude 4.5 Haiku

For customer support, live chat, or interactive applications where speed is critical:

• Ultra-fast response times
• Cost-effective for high volumes
• Good quality for straightforward tasks
• 200K context window

When to upgrade: If you need better reasoning or vision capabilities, consider Claude 4.5 Sonnet.

Complex Analysis & Research

Recommended: Claude 4 Sonnet

For data analysis, research, strategic planning, or complex problem-solving:

• Extended thinking for deep reasoning
• Highest intelligence across all tasks
• Vision support for documents/images
• Best for multi-step problems

Cost consideration: Premium pricing. Use Claude 4.5 Sonnet for similar quality at lower cost.

Code Generation & Review

Recommended: Claude 4.5 Sonnet or Claude 4 Sonnet

For development assistance, code review, or debugging:

• Strong coding capabilities
• Understands multiple languages
• Can analyze codebases with large context
• Good balance of speed and quality

For simple tasks: Claude 4.5 Haiku can handle basic code generation efficiently.

Content Creation

Recommended: Claude 4.5 Sonnet

For blog posts, marketing copy, or creative writing:

• Balanced quality and speed
• Natural, engaging writing style
• Large context for research integration
• Cost-effective for regular use

For high-volume: Use Claude 4.5 Haiku for shorter-form content.

Document Processing

Recommended: Claude 4.5 Sonnet or Claude 4 Sonnet

For extracting data, summarizing, or analyzing documents:

• Vision capabilities for PDFs and images
• 200K context window
• Structured output support
• Good accuracy

With extended thinking: Claude 4 Sonnet for complex document analysis.

Semantic Search & RAG

Recommended: Cohere Embed Multilingual + Claude 4.5 Haiku

For retrieval-augmented generation applications:

• Use Cohere for generating embeddings
• Store vectors in Postgres with pgvector
• Use Claude 4.5 Haiku for fast, cost-effective responses
• Upgrade to Claude 4.5 Sonnet for better synthesis

Benefit: Fast, accurate, cost-optimized for production.

Image Generation

Recommended: Stable Image Ultra

For marketing assets, product visualization, or creative content:

• High-quality photorealistic outputs
• Multiple aspect ratios
• Negative prompt support
• Reproducible with seeds

Best for: Marketing, social media, concept art.

Model Comparison by Use Case

Customer Support

Scenario	Recommended Model	Why
Simple FAQs	Claude 4.5 Haiku	Fastest, most cost-effective
Product support	Claude 4.5 Sonnet	Better reasoning, still fast
Technical support	Claude 4.5 Sonnet	Code understanding, good balance
Complex troubleshooting	Claude 4 Sonnet	Deep reasoning when needed

Development Tools

Scenario	Recommended Model	Why
Code completion	Claude 4.5 Haiku	Fast inline suggestions
Code generation	Claude 4.5 Sonnet	Good quality, reasonable speed
Code review	Claude 4.5 Sonnet	Thorough analysis capability
Architecture design	Claude 4 Sonnet	Complex reasoning required
Debugging	Claude 4 Sonnet	Extended thinking helps

Content & Marketing

Scenario	Recommended Model	Why
Social media posts	Claude 4.5 Haiku	Quick, high volume
Blog articles	Claude 4.5 Sonnet	Quality writing, research integration
Product descriptions	Claude 4.5 Haiku	Consistent, efficient
Brand strategy	Claude 4 Sonnet	Deep thinking required
Visual assets	Stable Image Ultra	High-quality images

Performance Characteristics

Speed Comparison

Claude 4.5 Haiku    ████████████████████ Fastest
Amazon Nova Lite    ████████████████░░░░ Very Fast
Claude 4.5 Sonnet   ███████████████░░░░░ Fast
Amazon Nova Pro     ██████████████░░░░░░ Medium
Claude 4 Sonnet     █████████░░░░░░░░░░░ Medium
Claude Opus 4.5     ████████░░░░░░░░░░░░ Slower

Intelligence Comparison

Claude Opus 4.5     ████████████████████ Highest
Claude 4 Sonnet     ███████████████████░ Very High
Claude 4.5 Sonnet   ██████████████████░░ High
Amazon Nova Pro     ████████████████░░░░ High
Claude 4.5 Haiku    █████████████░░░░░░░ Good
Amazon Nova Lite    ███████████░░░░░░░░░ Good

Cost Efficiency

Claude 4.5 Haiku    ████████████████████ Most efficient
Amazon Nova Lite    ██████████████████░░ Very efficient
Claude 4.5 Sonnet   ██████████████░░░░░░ Moderate
Amazon Nova Pro     ███████████░░░░░░░░░ Moderate
Claude 4 Sonnet     ████████░░░░░░░░░░░░ Higher cost
Claude Opus 4.5     ██████░░░░░░░░░░░░░░ Premium

Feature Matrix

Feature	Haiku 4.5	Sonnet 4.5	Sonnet 4	Opus 4.5	Nova Lite	Nova Pro
Context Window	200K	200K	200K	200K	1M	Large
Max Output	4K	8K	8K	8K	-	-
Vision	✗	✓	✓	✓	✗	✗
Extended Thinking	✗	✓	✓	✓	✓	✗
Tool Use	✓	✓	✓	✓	✓	✓
Speed	Fastest	Fast	Medium	Slower	Fast	Medium
Relative Cost	Low	Balanced	Premium	Premium	Low	Medium

Making the Trade-off

When Speed Matters Most

Choose Claude 4.5 Haiku if:

• Real-time responses are critical
• You have high request volumes
• Tasks are relatively straightforward
• Cost optimization is important

Trade-off: Simpler reasoning, shorter outputs

When Quality Matters Most

Choose Claude 4 Sonnet if:

• Task requires deep analysis
• Multi-step reasoning is needed
• Extended thinking provides value
• Cost is secondary to quality

Trade-off: Slower responses, higher cost

When Balance Matters Most

Choose Claude 4.5 Sonnet if:

• You need good quality and reasonable speed
• Vision capabilities are required
• Building general-purpose applications
• Budget is moderate

Trade-off: No extended thinking, moderate cost

Testing Strategy

1. Start Conservative

Begin with Claude 4.5 Haiku for most tasks:

• Lowest cost for testing
• Fast iteration
• Good baseline performance

2. Test Upward

If quality isn’t sufficient, test with Claude 4.5 Sonnet:

• Better reasoning
• Vision support
• Still reasonable cost

3. Use Premium Selectively

Reserve Claude 4 Sonnet for:

• Clearly complex tasks
• High-value operations
• When extended thinking provides measurable benefit

4. Use AI Studio

Test different models interactively:

1. Open AI Studio
2. Try the same prompt with different models
3. Compare quality, speed, and output
4. Export code when satisfied

Cost Optimization Tips

Use the Right Model for Each Task

# Example: Multi-model approach
def process_request(request_type, content):
    if request_type == "simple_query":
        return call_model("claude-4-5-haiku", content)
    elif request_type == "analysis":
        return call_model("claude-4-5-sonnet", content)
    elif request_type == "complex_reasoning":
        return call_model("claude-4-sonnet", content)

Implement Caching

from functools import lru_cache

@lru_cache(maxsize=1000)
def get_embedding(text):
    """Cache embeddings to avoid redundant API calls"""
    return client.embeddings.create(
        model="cohere-embed-multilingual",
        input=[text]
    )

Set Token Limits

response = client.chat.completions.create(
    model="claude-4-5-sonnet",
    messages=messages,
    max_tokens=500  # Limit output length
)

Batch When Possible

# Batch embeddings instead of individual requests
texts = ["text1", "text2", "text3", ...]
response = client.embeddings.create(
    model="cohere-embed-multilingual",
    input=texts  # Up to 96 strings
)

Common Mistakes to Avoid

Don’t use Claude 4 Sonnet for everything. While it’s the most capable model, it’s also the most expensive. Reserve it for tasks that truly need extended thinking.

Don’t forget about context limits. Even with 200K context windows, larger contexts increase costs. Summarize or filter content when possible.

Don’t ignore speed requirements. For real-time applications, choose Haiku models even if quality is slightly lower. User experience matters.

Don’t skip testing. What works for one use case may not work for another. Always test with real data before production deployment.

Migration Path

Starting Simple

1. Launch with Claude 4.5 Haiku
   ↓
2. Monitor quality metrics
   ↓
3. Identify tasks that need better quality
   ↓
4. Upgrade those tasks to Claude 4.5 Sonnet
   ↓
5. Reserve Claude 4 Sonnet for complex cases

Gradual Optimization

Phase 1: Single model (Claude 4.5 Sonnet)
  ↓
Phase 2: Two-tier (Haiku for simple, Sonnet for complex)
  ↓
Phase 3: Three-tier (Haiku/Sonnet/Sonnet 4)
  ↓
Phase 4: Task-specific routing with monitoring

Getting Help

Still not sure which model to choose?

1. Start with AI Studio: Test interactively with real prompts
2. Check the comparison table: Review side-by-side metrics
3. Review use case examples: Find similar applications
4. Monitor and iterate: Track quality and costs in production

Related Resources

Models overview

Detailed specifications for all models

Pricing

Understand costs for each model

AI Studio

Test models interactively

Chat Completions API

Start using models in production