Claude 3.7 Sonnet vs GPT-4o: Code Writing Speed Comparison

Claude 3.7 Sonnet vs GPT-4o: Code Writing Speed Comparison

llmwizard
5/8/2025

When embarking on a major code refactoring, your choice of Claude 3.7 Sonnet vs GPT-4o can make a major difference. Both advanced AI models offer speed, accuracy, and flexibility in transforming legacy code. This practical comparison looks at latency, throughput, cost, and integration. You’ll see how each generative AI solution tackles extensive code edits and which one fits your workflow better. Real-world scenarios, best practices, and how LLMWizard’s one-click model switching keeps your CI/CD pipeline seamless are also covered.

Why Speed Matters in Code Refactoring

Refactoring encompasses syntax updates, pattern extraction, and dependency changes. Slow AI responses stall continuous integration and increase merge conflict risks. Fast model responses keep pull requests flowing. High throughput finishes batch edits faster. Low latency preserves developer flow. Accuracy prevents regressions and shortens QA cycles. For a software engineer, performance is as critical as reliability. This guide helps you pick the fastest and most precise model for your next refactoring project.

Testing Environment and Methodology

We established a controlled lab to measure Claude 3.7 Sonnet and GPT-4o on code refactoring tasks. Key elements:

  • A mixed base of 10,000 lines of Python and Java code

  • 50 distinct refactoring prompts (variable renaming, API transitions, pattern extraction)

  • The same server specs and stable network conditions

  • Automated scripts monitoring response time, token throughput, and test pass rates

LLMWizard’s unified API was employed to transfer requests and logs. This approach ensures fair comparison and reproducible results.

Latency and Throughput

Latency affects the feel of interactive edits, while throughput shapes batch operations.

  • Claude 3.7 Sonnet:
    • Latency: avg. 180 ms
    • Throughput: 3,200 tokens/sec

  • GPT-4o:
    • Latency: avg. 120 ms
    • Throughput: 2,800 tokens/sec

GPT-4o leads in single-prompt response speed. Claude 3.7 Sonnet processes larger requests faster and maintains higher throughput in long runs.

Accuracy in Code Refactoring

Accuracy measures whether refactored code passes unit and integration tests.

  • Claude 3.7 Sonnet: 98.2% pass rate

  • GPT-4o: 97.5% pass rate

Errors were divided into two categories: edge case formatting and dependency mismatches. Claude 3.7 Sonnet’s deeper context retention reduced mapping errors. GPT-4o’s speed occasionally led to minor accuracy dips in large files.

Performance Summary Table

ModelLatency (ms)Throughput (tokens/sec)Accuracy (%)Cost/1K tokens
Claude 3.7 Sonnet1803,20098.2$0.0032
GPT-4o1202,80097.5$0.0040

Cost Comparison and Budget Control

Code refactoring often spans millions of tokens. Small cost differences add up:

  • Claude 3.7 Sonnet: $0.0032 per 1K tokens

  • GPT-4o: $0.0040 per 1K tokens

While automating large-scale refactoring, a $0.0008 per 1K tokens savings accumulates over time. Avoid surprises by utilizing LLMWizard’s budget controls and alerts on its pricing page. You can receive email notifications as you approach limits.

Integration and One-Click Model Switching

Seamless model switching keeps your CI/CD pipeline agile. LLMWizard’s one-click model switching facilitates requests between models like Claude 3.7 Sonnet, GPT-4o, and others without code changes.

A quick Python example:

from llmwizard import Clientclient = Client(api_key="YOUR_API_KEY")# Choose "claude-3.7-sonnet" or "gpt-4o"client.set_model("gpt-4o")prompt = "Refactor this Python function using list comprehension"response = client.generate(prompt)print(response.text)

Set an environment variable to change models in CI:

export LLMW_MODEL=claude-3.7-sonnet

No redeployment needed. Explore other engines on the AI models page.

Real-World Use Cases

Microservice Refactoring

Consistency is critical when breaking a monolith into microservices. Claude 3.7 Sonnet’s throughput updates hundreds of endpoints. GPT-4o’s low latency supports live coding sessions.

Frontend Component Cleanup

React or Vue component libraries frequently require prop renaming. GPT-4o offers rapid feedback within IDE plugins. Claude 3.7 Sonnet handles hundreds of files at once.

Legacy API Migrations

Precise mapping is essential when transitioning from REST to GraphQL or gRPC. Claude 3.7 Sonnet’s accuracy reduces manual review. GPT-4o speeds up prototype migration scripts.

Best Practices for Model Selection in CI/CD

  1. Define performance goals: latency for quick edits, throughput for batch jobs.

  2. Automate canary testing: run rapid refactoring on a small module.

  3. Track core metrics: monitor response time and token usage on dashboards.

  4. Use fallback chains: start with GPT-4o, switch to Claude 3.7 Sonnet for heavy loads.

  5. Budget alerts: Configure spend warnings on pricing plans console.

These steps help optimize speed, cost, and code quality.

Conclusion and Next Steps

Balancing speed, accuracy, and cost is key to efficient code refactoring. GPT-4o offers the fastest single-response latency. Claude 3.7 Sonnet stands out in throughput and minor accuracy advantages. Test both instantly on live workloads with LLMWizard’s one-click model switching. Start your 14-day trial to measure latency, cost, and code accuracy without any risk. See which model suits your engineering workflow best.

LLMWizard in 60 Seconds

  • One-click switching between top LLMs

  • Unified API for Claude 3.7 Sonnet, GPT-4o, and more

  • Real-time model changes in CI/CD pipelines

  • Centralized usage and cost dashboards

  • Flexible token budgeting and spend alerts

  • Full-access 14-day free trial

Try both models – free trial

Q: How does LLMWizard’s one-click switching work?
A: You set your preferred model ID in the SDK or as an environment variable. The platform routes API calls without requiring code changes or redeployment.

Q: How much code volume can these models handle?
A: Claude 3.7 Sonnet can handle large-scale batch refactoring up to the model’s context limit. GPT-4o handles interactive edits quickly. Both scale well in streaming mode via LLMWizard.

Q: Can I compare cost and performance in real-time?
A: Yes. The LLMWizard dashboard tracks latency, throughput, and spend per model. Detailed metrics are available in the pricing plans section, allowing for budget adjustments as needed.