QUICK ANSWERStart with the tool that matches your immediate input.
Open Tab Order Planner first when its stated purpose matches the result you need now. Use Touch Target Size Checker only when it solves a separate next task.
This guide is for designers, developers, editors, and site owners. Start with Tab Order Planner when your immediate task is to check common tab order planner issues and receive practical improvement guidance. Move to Touch Target Size Checker only when you also need to check common touch target size issues and receive practical improvement guidance.
The goal is not to run two tools automatically. It is to finish the first narrow task, inspect its result, and then decide whether Touch Target Size Checker solves a genuinely different next step.
Both tools sit in Accessibility Tools, but they handle different inputs or outcomes. Keeping those roles separate reduces repeated work and makes verification easier.