QUICK ANSWERStart with the tool that matches your immediate input.
Open HTML to Markdown first when its stated purpose matches the result you need now. Use Markdown to HTML only when it solves a separate next task.
This guide is for writers, office teams, students, and data workers. Start with HTML to Markdown when your immediate task is to convert your file or data with the HTML to Markdown directly in your browser. Move to Markdown to HTML only when you also need to convert your file or data with the Markdown to HTML directly in your browser.
The goal is not to run two tools automatically. It is to finish the first narrow task, inspect its result, and then decide whether Markdown to HTML solves a genuinely different next step.
Both tools sit in Documents & Files, but they handle different inputs or outcomes. Keeping those roles separate reduces repeated work and makes verification easier.