Claude vs GPT: Choosing the Right LLM for Your Application

Anthropic’s Claude models offer a compelling alternative to OpenAI’s GPT. Here’s a practical comparison to help you decide which is right for your use case.

Model Comparison

Feature	GPT-4 Turbo	Claude 2.1
Context Window	128K	200K
Input Cost	$0.01/1K	$0.008/1K
Output Cost	$0.03/1K	$0.024/1K
API Provider	OpenAI/Azure	Anthropic

API Usage

GPT-4

from openai import OpenAI

client = OpenAI()

response = client.chat.completions.create(
    model="gpt-4-turbo",
    messages=[
        {"role": "system", "content": "You are a helpful assistant."},
        {"role": "user", "content": "Analyze this contract for key risks."}
    ]
)

Claude

from anthropic import Anthropic

client = Anthropic()

response = client.messages.create(
    model="claude-2.1",
    max_tokens=4096,
    messages=[
        {"role": "user", "content": "Analyze this contract for key risks."}
    ]
)

Key Differences

Instruction Following

# Claude tends to follow instructions more literally
# GPT-4 sometimes takes more creative liberties

prompt = """
List exactly 5 bullet points about Python, no more, no less.
"""

# Claude: Reliably returns exactly 5 points
# GPT-4: Usually 5, occasionally adds context

Long Document Processing

# Claude's 200K context enables processing entire books
def process_long_document(document: str, model: str):
    if len(document) > 100000 and model.startswith("gpt"):
        # Need to chunk for GPT-4
        return process_in_chunks(document)
    elif model.startswith("claude"):
        # Can process in single call
        return process_full(document)

Safety and Refusals

# Claude is generally more conservative
# GPT-4 has more nuanced content policy

sensitive_prompts = {
    "medical_advice": "Both provide with disclaimers",
    "code_security": "Both assist with caveats",
    "creative_writing": "GPT-4 slightly more flexible",
    "controversial_topics": "Claude more likely to refuse"
}

Use Case Recommendations

Claude Excels At

claude_strengths = [
    "Very long document analysis (200K context)",
    "Precise instruction following",
    "Constitutional AI alignment",
    "Detailed explanations and reasoning",
    "Academic and research content"
]

GPT-4 Excels At

gpt4_strengths = [
    "Complex function calling",
    "Creative content generation",
    "Broader plugin ecosystem",
    "Azure enterprise integration",
    "Multimodal capabilities (Vision)"
]

Hybrid Approach

class HybridLLMRouter:
    def __init__(self, openai_client, anthropic_client):
        self.openai = openai_client
        self.anthropic = anthropic_client

    def route_and_call(self, prompt: str, context_length: int, task_type: str):
        """Route to best model based on task."""

        if context_length > 100000:
            return self._call_claude(prompt)

        if task_type == "creative":
            return self._call_gpt4(prompt)

        if task_type == "analysis" and context_length > 50000:
            return self._call_claude(prompt)

        if task_type == "function_calling":
            return self._call_gpt4(prompt)

        # Default based on cost for simple tasks
        return self._call_claude(prompt)

    def _call_claude(self, prompt: str) -> str:
        response = self.anthropic.messages.create(
            model="claude-2.1",
            max_tokens=4096,
            messages=[{"role": "user", "content": prompt}]
        )
        return response.content[0].text

    def _call_gpt4(self, prompt: str) -> str:
        response = self.openai.chat.completions.create(
            model="gpt-4-turbo",
            messages=[{"role": "user", "content": prompt}]
        )
        return response.choices[0].message.content

Looking Ahead

Anthropic has hinted at Claude 3 coming soon, which promises even better performance across benchmarks. Meanwhile, OpenAI continues to iterate on GPT-4. The multi-model future is here, and smart architectures will leverage the strengths of each provider.

Conclusion

Both Claude 2.1 and GPT-4 are excellent choices. Claude offers longer context and stricter instruction following; GPT-4 provides broader ecosystem support and better tool use. Consider using both for their respective strengths.