QUICK ANSWERStart with the tool that matches your immediate input.
Open JSON Lines Validator first when its stated purpose matches the result you need now. Use JSON Schema Draft Generator only when it solves a separate next task.
This guide is for developers, analysts, testers, and technical writers. Start with JSON Lines Validator when your immediate task is to use the JSON Lines Validator to inspect, transform, validate, or generate developer data locally in your browser. Move to JSON Schema Draft Generator only when you also need to use the JSON Schema Draft Generator to inspect, transform, validate, or generate developer data locally 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 JSON Schema Draft Generator solves a genuinely different next step.
Both tools sit in Developer & Data, but they handle different inputs or outcomes. Keeping those roles separate reduces repeated work and makes verification easier.