Images are usually the heaviest thing on a web page, so the format you choose has a direct effect on load time, Core Web Vitals, bandwidth costs and search rankings. This guide compares JPEG, PNG, WebP and AVIF in plain terms and gives you a simple rule for picking the right one every time.
Why the format matters
Two versions of the same image can differ in file size by 5× or more depending on the format and compression. Smaller images load faster, which improves the Largest Contentful Paint metric Google uses for ranking, reduces mobile data usage, and lowers hosting/CDN costs. Choosing well — and compressing properly — is one of the highest-impact, lowest-effort performance wins available.
JPEG
JPEG (or JPG) is the classic format for photographs. It uses lossy compression, discarding detail the eye barely notices to achieve small files. It has no transparency support.
- Best for: photos, complex images with many colors and gradients.
- Avoid for: logos, text, sharp edges (compression artifacts show), or anything needing transparency.
PNG
PNG uses lossless compression and supports transparency (an alpha channel). Nothing is thrown away, so quality is perfect — but files are large for photographic content.
- Best for: logos, icons, screenshots, line art, and any image that needs a transparent background or crisp edges.
- Avoid for: large photographs, where it produces needlessly heavy files.
WebP
WebP, developed by Google, is the modern all-rounder. It supports both lossy and lossless compression and transparency, and typically produces files 25–35% smaller than an equivalent JPEG or PNG at similar quality. It is supported by every current browser.
- Best for: almost everything on the modern web — photos and graphics alike.
- Watch out for: very old browsers (provide a JPEG/PNG fallback if you must support them).
AVIF (and what's next)
AVIF is a newer format based on the AV1 video codec. It often beats WebP on compression, especially for photos, and supports transparency and HDR. Browser support is now broad but slightly behind WebP. A common modern strategy is to serve AVIF with a WebP fallback and a JPEG/PNG last resort using the <picture> element.
Side-by-side comparison
| Format | Compression | Transparency | Best use |
|---|---|---|---|
| JPEG | Lossy | No | Photographs |
| PNG | Lossless | Yes | Logos, screenshots, transparency |
| WebP | Both | Yes | Modern web default |
| AVIF | Both | Yes | Best compression, with fallback |
How to choose (the simple rule)
- Photograph? Use WebP (or AVIF with a JPEG fallback). Plain JPEG is a fine, universally-supported default.
- Logo, icon, screenshot, or needs transparency? Use WebP lossless, or PNG for maximum compatibility.
- Always compress after exporting — most images ship far larger than they need to be.
You can convert between all of these and shrink file sizes with our free browser tools: the Image Converter switches formats, and the Image Compressor reduces file size without visible quality loss. Both run locally in your browser, so your images never leave your device.
FAQ
Is WebP better than PNG and JPEG?
For most web use, yes — WebP produces smaller files than both at comparable quality, and it supports transparency like PNG. Keep a JPEG/PNG fallback only if you must support very old browsers.
Does converting to WebP lose quality?
Lossy WebP discards some data like JPEG, but at a given quality level it usually looks as good while being smaller. WebP also has a lossless mode for graphics where quality must be perfect.
Which format is best for logos?
PNG or lossless WebP, because they keep sharp edges and support transparency. For scalable logos, SVG is even better where you control the markup.
How much smaller is WebP?
Typically 25–35% smaller than an equivalent JPEG or PNG, though the exact saving depends on the image and quality setting.