JA Tool

Image Compression Inspector: Guide

Inspect size, resolution, and compression hints to pick a better image format.

What it does

Shows file size and resolution (width × height)
Gives rough hints about compression / optimization room
Helps you decide between PNG / JPEG / WebP (if supported by the tool)
Browser-only, no storage

Open the tool 日本語ガイド

Use this when

You want to ensure images aren’t too heavy before posting
Your site feels slow due to large images
You’re unsure if PNG should be JPEG/WebP instead

Keywords: image optimization, compression ratio, PNG vs JPEG vs WebP, image size checker

How to use

Open the tool
Select an image (or drag & drop)
Read the results (size, resolution, format hints)

Tip: compare the same image exported as PNG/JPEG/WebP and decide with numbers.

Notes (limits)

“Best” depends on your use case (photo, illustration, transparency). Use hints as guidance.
The tool may inspect only; it might not re-compress/convert (depending on implementation).
It cannot judge subjective visual quality.