To get WebP images, should I use the format converter or the image compressor?

What the two tools share

Both run inside your browser, accept JPEG, PNG and WebP, save WebP with a quality slider, show the size before and after for each image, drop EXIF data because the picture is redrawn, and let you download everything as a ZIP. That is why choosing between them is confusing at first. The differences are in the details.

The differences that decide it

• Files that are already WebP: the converter leaves them unconverted with a note, so they will not shrink. The compressor re-encodes them at the chosen quality.
• PNG output: the converter offers PNG as a target. The compressor outputs JPEG or WebP only.
• File names: the converter keeps the name and changes only the extension; the compressor adds the word compressed to the name.
• What the report is about: the converter focuses on what happened to the format, such as lost transparency or a file left as is. The compressor focuses on the size saving.

Three situations and which tool fits

1. Transparent PNG logos you want as WebP for your website: the Image format converter. Transparency and names stay the same, which makes swapping the files on your site easy.
2. Heavy WebP images saved from a supplier's site that you want lighter for your store: the Image compressor. The converter would tell you they are already WebP and change nothing.
3. A mix of JPEG and WebP that should all be WebP and smaller: start with the compressor set to WebP, which re-encodes the lot in one pass, WebP files included.

Why the converter leaves same-format files alone

Re-encoding a WebP as WebP does not change its format, and whatever does change is fresh quality loss. Someone who opens a format converter wants a different format, so the sensible behavior is to say the file is already there rather than quietly shave detail off it. In the tool's logic, WebP to WebP is an explicit skip. The compressor's job is to slim files down, so the deliberate loss is part of the task, which is why it always re-encodes and tells you if a file came out bigger.

Should I use both?

Sometimes, in order: convert first to get the format you need, then compress if you need a smaller size. For example, a PNG you need as JPEG for a platform with a strict size cap: convert it at quality 90, and if it is still over the limit, compress it. But if the goal from the start is a smaller JPEG or WebP, the compressor alone is enough, since it accepts PNG and converts and compresses in one step.