JPEG, PNG or WebP: choose an image format

Start with the destination

Before adjusting quality, check the allowed file types, maximum pixel dimensions and file-size limit. A website thumbnail, an application form and a print document can need very different files.

Keep the original separately. Work on a copy so a quick export does not become your only version of a photograph or design.

Photographs: compare JPEG and WebP

Photos contain gradients and fine texture that often suit lossy compression. Start with a moderate-to-high quality export, then reduce quality gradually while viewing the image at the size people will actually see.

Look at hair, foliage, skies and high-contrast edges. If the file is still too large, reducing its dimensions may give a more useful result than pushing quality extremely low.

• JPEG is a practical option when a receiving service explicitly asks for a .jpg file.
• WebP is worth comparing when the destination supports it.
• Compare actual file sizes: converting an already compressed photo is not guaranteed to save space.

Screenshots and diagrams: protect sharp edges

Small text, chart labels and flat-color edges can become fuzzy or develop halos with aggressive lossy compression. PNG is a useful starting point when crisp reproduction matters.

The PNG quality control does not work like JPEG quality in a browser export. If a PNG is too large, first remove unnecessary dimensions or try another accepted format and inspect the small text carefully.

Transparent backgrounds need the right format

A logo or cutout can contain partly transparent edge pixels, not just fully transparent areas. PNG and WebP can retain this transparency, while JPEG cannot.

ToolRook places a white background behind transparency when exporting JPEG. If the image must sit on a colored website section, keep a transparent format and preview it on that actual background.

Resize, export and check the real result

A 4000 × 3000 image has four times as many pixels as a 2000 × 1500 image. Reducing dimensions can therefore remove a large amount of unnecessary image data, though file size will not necessarily fall by the same ratio.

Download the output and open it in the application that will use it. Check orientation, transparency, sharpness and file size. Browser exports create a new still image; do not rely on them to preserve animation, metadata or the original color profile.

• Choose suitable pixel dimensions before fine-tuning export quality.
• Avoid repeatedly re-saving an already lossy image; return to the original when trying a different setting.
• Keep the original if the new export is larger or looks worse.