Image File Formats Explained: JPG, PNG, WebP, GIF, SVG & AVIF
JPG, PNG, WebP, GIF, SVG, AVIF — what's the difference and when do you use each? Here's a plain-English guide, plus how to convert between them free.
JPG, PNG, WebP, GIF, SVG, AVIF... image formats can feel like alphabet soup. But each exists for a reason, and once you know what each is *for*, choosing the right one is easy. Here's a plain-English guide to the main image file formats — and how to convert between them free when you need to.
JPG (JPEG) — for photographs
The workhorse of photography. JPG uses *lossy* compression to make photos small, at a tiny (usually invisible) quality cost. It's supported everywhere.
Use it for: photographs, and anything you're sharing or uploading where small size matters.
Weakness: no transparency; re-saving repeatedly slowly degrades quality; adds artefacts around sharp edges and text.
PNG — for graphics & transparency
PNG is *lossless* and supports transparency. It keeps every pixel exact, so lines, text, and edges stay crisp.
Use it for: logos, icons, screenshots, graphics, and anything needing a transparent background.
Weakness: large files for photographs — much bigger than JPG for the same photo.
WebP & AVIF — the modern web formats
WebP (Google) and AVIF (newer, even more efficient) are modern formats built for the web. Both compress smaller than JPG at the same quality and support transparency; AVIF is typically the smallest of all.
Use them for: website images, to speed up loading.
Weakness: compatibility — some older apps and platforms don't accept them, which is why people convert WebP/AVIF back to JPG or PNG.
GIF & SVG — animation and vectors
GIF is an old format limited to 256 colours, used mainly for simple animations (memes, reaction loops). It's poor for photos.
SVG is a vector format — it scales to any size without blurring, perfect for logos and icons. But it's not a pixel image, so many apps can't display or accept it.
Convert GIF → PNG to grab a still frame; SVG → PNG when an app needs a raster image.
How to convert between formats (free)
Whenever you have the wrong format, converting is instant: open JPT AI's converter at sjpt.io, upload your image, choose the output (JPG, PNG or WebP), and download. No watermark, no sign-up, private in your browser. Popular one-click routes: PNG → JPG, WebP → JPG, JPG → WebP, SVG → PNG, GIF → PNG, and more.
Frequently asked questions
Which image format should I use?Photos → JPG (or WebP for web). Graphics/logos/transparency → PNG. Web speed → WebP/AVIF. Animation → GIF. Scalable logos → SVG.
What's the smallest image format?AVIF is usually the smallest, then WebP, then JPG — but AVIF/WebP have less universal compatibility.
Can I convert between all these formats?You can convert to JPG, PNG or WebP from common inputs (including SVG, GIF, AVIF, BMP) free at JPT AI.
Why won't my WebP/AVIF file open?Some older software doesn't support them. Convert to JPG or PNG and it'll open anywhere.
Key takeaways
Each format has a job: JPG for photos, PNG for graphics/transparency, WebP/AVIF for fast web images, GIF for simple animation, SVG for scalable logos. When you have the wrong one, convert free in seconds at sjpt.io. Convert Image Free →
