JPG vs PNG vs WebP vs AVIF: Which Image Format to Use

Toolgix team · November 9, 2026

Choosing the wrong format is the most common reason an image is ten times bigger than it needs to be. The right choice depends on what is in the picture and where it will be used.

The short answer

The formats

JPG (JPEG)

Lossy, made for photographs, universally supported. No transparency. Re-saving a JPG repeatedly loses a little quality each time, so edit from the original.

PNG

Lossless: every pixel is kept exactly. Supports transparency. Ideal for screenshots, diagrams and graphics with flat colours; usually far larger than JPG for photos.

WebP

Has both lossy and lossless modes, transparency and animation. Typically smaller than JPG or PNG for similar quality and supported by current versions of all major browsers. Some desktop software and upload forms still do not accept it — convert to JPG for those.

AVIF

A newer format based on the AV1 video codec. Often smaller than WebP at the same visual quality, supported by current major browsers, but slower to encode and less widely accepted outside the web. Toolgix can read AVIF and convert it to JPG, PNG or WebP.

SVG

Not pixels but drawing instructions, so it stays sharp at any size. Perfect for logos and icons; not for photos. Convert to PNG when a service requires a bitmap: SVG to PNG.

On websites

• Serve images at the size they are displayed (×2 for high-density screens), not the camera’s original size.
• Use WebP or AVIF with a JPG/PNG fallback if you support very old browsers (the HTML picture element does this).
• Always set width and height attributes so the page does not jump while images load.

Sources

• MDN: Image file type and format guide
• web.dev: Choose the right image format