QUICK ANSWERStart with the tool that matches your immediate input.
Open Batch Image Compressor first when its stated purpose matches the result you need now. Use Batch Image Resizer only when it solves a separate next task.
This guide is for creators, marketers, designers, and website owners. Start with Batch Image Compressor when your immediate task is to use the Batch Image Compressor to complete this file task privately in your browser. Move to Batch Image Resizer only when you also need to use the Batch Image Resizer to complete this file task privately 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 Batch Image Resizer solves a genuinely different next step.
Both tools sit in Image & Design, but they handle different inputs or outcomes. Keeping those roles separate reduces repeated work and makes verification easier.