Claude Sonnet is the strongest fit for extracting structured data from messy text like emails and web scrapes. You can paste raw text and prompt it to return clean JSON, CSV, or any schema you define, and it handles inconsistent formatting, missing fields, and varied phrasing reliably. It also supports long contexts, which matters when processing bulk email threads or large scraped pages. Claude Haiku is a faster and cheaper alternative when you are processing high volumes at the API level, while ChatGPT works well if you prefer OpenAI's function-calling and structured-output features for schema enforcement.