Most image format decisions come down to three questions: is it a photo or a graphic, does it need transparency, and where is it going? Answer those and the right format is usually obvious. This guide explains the six formats you’ll meet most often and gives simple rules for picking between them.
The quick answer
- Photo to share, email, print or upload anywhere: JPG.
- Logo, icon, screenshot or anything with transparency: PNG.
- Photo or graphic for your own website: WebP, or AVIF if your setup supports it.
- Logo or icon on a website, at any size: SVG.
- iPhone photos: they arrive as HEIC. Convert them to JPG before sharing with non-Apple devices.
- A master copy you’ll keep editing: PNG, or your editor’s own format.
Photos and graphics need different formats
Photos have millions of slightly different colours and soft transitions. Lossy formats such as JPG, WebP, AVIF and HEIC handle them well: they discard detail your eye won’t miss and produce small files.
Graphics, screenshots and text have flat colours and hard edges. Lossy compression smudges those edges, so lossless formats such as PNG, or vector formats such as SVG, keep them crisp. A screenshot saved as JPG shows faint blotches around every letter; the same screenshot as PNG is perfect and often smaller.
Lossy and lossless, in one paragraph
Lossless compression packs the data more tightly but restores every pixel exactly, like a ZIP file. Lossy compression permanently throws some detail away in exchange for much smaller files. You can’t get the detail back by converting to a lossless format later. Converting a JPG to PNG makes a perfect copy of the JPG, artefacts and all. Each time you re-save a lossy file, a little more is lost. So keep originals, and compress once, at the end.
The formats compared
| Format | Compression | Transparency | Best for | Watch out for |
|---|---|---|---|---|
| JPG | Lossy | No | Photos everywhere | Artefacts on text, re-save loss |
| PNG | Lossless | Yes | Graphics, screenshots, editing | Large photo files |
| WebP | Both | Yes | Website images | Some apps and forms reject it |
| AVIF | Both | Yes | Smallest web images, HDR | Slow to create, patchy app support |
| HEIC | Lossy | Yes | iPhone photo storage | Hard to open outside Apple devices |
| SVG | Vector | Yes | Logos, icons, diagrams | Not accepted by many platforms |
Choosing by situation
Sharing photos with people
Use JPG. Every phone, computer, messaging app and email client opens it. If you’re on an iPhone, your photos are probably HEIC; many apps convert them automatically when you share, but files copied over a cable or downloaded from cloud storage may stay HEIC. Convert them to JPG first if the recipient uses Windows or Android.
Uploading to forms, shops and official websites
Use JPG for photos and PNG for documents, signatures or scans with text. Many upload forms reject WebP, AVIF and HEIC. If a form has a size limit, lower the JPG quality to 70–80% rather than shrinking the image dimensions, unless the image is very large.
Publishing on your own website
Use WebP for photos and most graphics. It is supported by every current browser and is typically 25–35% smaller than JPG. AVIF is smaller still, but slower to create; it’s worth it when your image service generates it automatically. Use SVG for logos and icons, and PNG only where you need lossless detail and WebP isn’t an option. Whatever the format, resize images to the size they’re shown at: a 4000-pixel photo shown 800 pixels wide wastes most of its bytes.
Images with transparent backgrounds
Use PNG when it must open everywhere, WebP when it’s for a website. JPG can’t do transparency: see-through areas become a solid colour, usually white or black.
Editing and keeping master copies
Keep the original camera file or a PNG. Edit from that, and export to JPG or WebP only for the final, shared version. That avoids stacking up compression loss with every save.
Printing
Use high-quality JPG (90% or higher) or PNG. Print shops rarely accept WebP, AVIF or HEIC. Image resolution matters more than format here: for a sharp print, aim for about 300 pixels per inch of print size.
Things that change when you convert
Converting between formats isn’t only about the format name. Check these:
- Transparency is lost when converting to JPG.
- Animation is lost when converting animated WebP, AVIF or GIF to a still format; you get the first frame.
- Metadata such as camera details and GPS location may be removed. xconverter writes new files from the pixels only, so location data never travels with converted files.
- Colour range: HDR photos from HEIC or AVIF are converted to standard range for JPG and PNG.
- File size can go up as well as down. HEIC, AVIF and WebP compress better than JPG, so converting from them to JPG usually makes bigger files.
Summary
JPG for photos you share, PNG for graphics and transparency, WebP or AVIF for websites, SVG for logos, and convert HEIC before it leaves your Apple devices. Keep an original, and compress once.