JPG vs PNG vs WebP: Which Format to Use and How to Convert

JPG, PNG and WebP are the three image formats you meet most online. They store pictures differently, so the right choice depends on what is in the image and where it is going. This guide explains the differences, when converting helps (and when it only makes files bigger), and how to convert for free with Uvolix or apps you already have.

The short answer

JPG: the photo format

JPG throws away detail the eye barely notices, which makes photos small. Each time you edit and re-save a JPG, a little more detail is lost, and sharp edges such as text can show fuzzy "artefacts". It cannot store transparency.

PNG: sharp graphics and transparency

PNG keeps every pixel exactly, so text, screenshots, logos and icons stay crisp, and it supports transparent backgrounds. For photographs, the same exactness makes PNG files several times larger than a JPG of the same picture.

WebP: the modern web format

WebP can work like a JPG (lossy) or a PNG (lossless) and supports transparency. Google, which created it, reports lossless WebP files about 26% smaller than PNG and lossy WebP 25–34% smaller than comparable JPGs. Many websites now serve WebP, which is why "Save image as" sometimes gives you a .webp file your other apps will not open.

When converting helps, and when it does not

• WebP → JPG: when an app, printer or upload form does not accept WebP.
• PNG → JPG: to shrink a large photo saved as PNG, or when a form only accepts JPG. Transparent areas become a solid background colour.
• JPG → PNG: when a tool or platform requires PNG, or before editing graphics you will re-save many times. It does not restore lost detail, and the file usually gets larger. In one test a 15 KB JPG became a 39 KB PNG.
• To make any image smaller, use the Image Compressor or Image Resizer instead of switching formats.

Convert for free in your browser

• PNG to JPG: choose the JPG quality (30–100%, 88% by default) and the background colour used where the PNG was transparent (white by default).
• WebP to JPG: the same quality and background options.
• JPG to PNG: a lossless copy of the JPG as it is.

Select the image (up to 50 MB), convert, check the preview and download. Images are processed on your device and not uploaded. Need a PDF instead? Use JPG to PDF.

Convert with built-in apps

• Mac: open the image in Preview, choose File → Export, pick JPEG or PNG and set the quality.
• Windows: open the image in Paint, choose File → Save as, and pick JPEG or PNG.
• iPhone photos in HEIC: Settings → Camera → Formats → Most Compatible makes new photos JPG. Existing HEIC photos are usually converted to JPG automatically when shared by email or to many apps.

Quality tips

• Convert from the best original you have; converting a converted file compounds losses.
• For photos, JPG quality 80–90% is usually visually identical to 100% at a fraction of the size.
• Keep logos and screenshots as PNG unless size forces a change.
• Check transparent images after converting to JPG; pick a background colour that matches where the image will be used.

FAQ

Is JPEG the same as JPG?

Yes. They are two extensions for the same format.

Does converting PNG to JPG reduce quality?

Slightly, because JPG is lossy. At 85–90% quality the difference is hard to see in photos, but text and sharp lines may soften.

Why will an image not open after I saved it from a website?

It is probably WebP. Convert it with WebP to JPG.

See all image tools on the image tools page.