JPG vs PNG vs WebP: Which Image Format Should You Use?

Choosing an image format sounds like a technical decision, but in practice it reduces to three questions: is the image a photograph, does it need transparency, and does anything old have to open it. Answer those and the format picks itself.

The short answer

• Photographs go in JPG, or WebP if you control where they will be viewed.
• Logos, icons, screenshots, and anything with transparency go in PNG.
• Images on your own website go in WebP, with a JPG or PNG fallback if you support old browsers.

JPG: lossy, and that is the point

JPG throws data away. Every time you save a JPG, the encoder discards detail it judges your eye will not miss, which is why a 4MB camera photo becomes a 400KB file that still looks fine.

That trade is excellent for photographs, where subtle gradations of colour hide the loss. It is bad for anything with hard edges. Save a screenshot of text as JPG and you will see fuzzy halos around the letters, because sharp black on white transitions are exactly what JPG compression handles worst.

JPG also has no transparency. There is no way to make part of a JPG see through to the background. If you need that, JPG is out.

One more property that catches people: JPG loss is cumulative. Open a JPG, edit it, save it, repeat, and quality degrades each time. Keep an original in a lossless format if you expect to edit repeatedly.

PNG: lossless, with an alpha channel

PNG never discards data. Save and resave as often as you like and the pixels are identical every time. It also supports full alpha transparency, so a logo can sit cleanly on any background colour.

The cost is size. For a photograph, a PNG can be five to ten times larger than the same image as JPG, because lossless compression cannot exploit the tolerance for loss that makes JPG so efficient. Saving photographs as PNG is the single most common cause of needlessly huge image files. If you have a PNG photo that will not fit an upload limit, converting it with PNG to JPG usually solves the problem in one step.

Where PNG earns its size: logos, icons, diagrams, screenshots, charts, and anything with flat colour areas and sharp edges.

WebP: the modern compromise

WebP does both jobs. It has a lossy mode that beats JPG on file size at comparable quality, and a lossless mode with transparency support like PNG. For images you serve on your own website, WebP is generally the right default, and it is why most image optimisation advice now points at it.

The catch is not browser support, which is broad now, but everything outside the browser. Email clients, older design software, some print workflows, and plenty of upload forms still do not accept WebP. If someone else has to open the file, or a form has to accept it, send JPG or PNG.

You can move between all three with the Image Format Converter, or use the direct JPG to PNG and PNG to JPG tools.

What about transparency you cannot see

A subtle trap: converting a transparent PNG to JPG does not preserve transparency, and it does not warn you either. The transparent areas get filled, usually with black or white. If your logo suddenly has a white box around it, this is why. Keep transparent assets in PNG or WebP.

A decision table

The bottom line

JPG trades detail for size and does it well on photographs. PNG keeps every pixel and supports transparency, which matters for graphics and costs you on photos. WebP does both better but is not universally accepted outside browsers. Match the format to the content and to who has to open it, and you will not go far wrong.