Can Claude 3.5/3.7 handle JSON schemas as strictly as GPT-4o?

Claude 3.5 and 3.7 handle JSON schemas well but with different characteristics than GPT-4o. Claude lacks native "structured outputs" mode like GPT-4o but can follow JSON schemas through careful prompting. GPT-4o with structured outputs provides mathematical guarantee of schema conformance. Claude follows schemas reliably when explicitly instructed but cannot guarantee adherence as strictly. In practice, Claude 3.5 Sonnet achieves 95%+ schema compliance with good prompts, versus GPT-4o structured outputs at 100%. Claude excels at complex reasoning within JSON constraints. GPT-4o structured outputs are better for critical applications requiring absolute schema conformance. Claude may handle nuanced semantic requirements better while being less strict about exact schema. Both models produce high-quality JSON for most use cases. Test with our JSON Validator at jsonconsole.com/json-editor to verify output. For production systems, validate outputs regardless of model. Choose GPT-4o for guaranteed schema compliance. Choose Claude for better reasoning when slight schema flexibility is acceptable. Both are production-ready with proper validation.