Image Format Comparison (PNG / JPG / WebP / AVIF / GIF)
A side-by-side comparison of the image formats you meet in web and app development, so you can pick the right one for each job.
Format comparison at a glance
The table below compares the main formats on compression, alpha transparency, animation support and browser coverage.
| Format | Compression | Transparency | Animation | Colour depth | Browser support |
|---|---|---|---|---|---|
| PNG | Lossless | Yes (8-bit alpha) | APNG (limited) | Up to 48-bit + 16-bit alpha | All browsers |
| JPEG | Lossy | No | No | 24-bit (about 16.7 million colours) | All browsers |
| WebP | Lossless or lossy | Yes (8-bit alpha) | Yes | 24-bit + 8-bit alpha | All major browsers (not IE) |
| AVIF | Lossless or lossy | Yes (8/10/12-bit alpha) | Yes (AVIF Sequence) | Up to 12-bit HDR | Chrome/Firefox/Safari 16.4+ |
| GIF | Lossless (LZW) | 1-bit (fully transparent or opaque only) | Yes | 8-bit (256 colours) | All browsers |
File size comparison
Rough file sizes for the same image saved in each format. The real numbers vary a lot with the picture content and the compression settings.
| Format | Photo (relative size) | Illustration (relative size) | Screenshot (relative size) |
|---|---|---|---|
| PNG | Large | Medium | Medium |
| JPEG (quality 80) | Small | Medium to large | Medium |
| WebP (quality 80) | Very small | Small | Small |
| AVIF (quality 60) | Very small | Very small | Very small |
| GIF | Not recommended | Large (limited to 256 colours) | Large |
Each format in detail, and when to use it
PNG（Portable Network Graphics）
Lossless, so nothing is degraded, and it supports alpha transparency. That makes it right for logos, icons, screenshots and anything containing text, where crisp edges matter. For photographic content it tends to produce large files.
- Best for: logos, icons, screenshots and anything needing transparency
- Avoid for: photographs — the files get needlessly large
JPEG（Joint Photographic Experts Group）
Lossy compression handles photographs and heavy gradients efficiently. A quality parameter from 0 to 100 trades size against fidelity. It supports neither transparency nor animation, but it can carry Exif metadata such as capture time and camera model.
- Best for: photographs, natural images, gradients
- Avoid for: text images and logos, where compression artefacts show, and anything needing transparency
WebP
Developed by Google, WebP cuts file size by roughly 25-34% against JPEG and about 26% against PNG. It offers both lossless and lossy modes and supports alpha transparency and animation. Every major browser except IE handles it.
- Best for: websites in general — it handles both photos and illustrations
- Avoid for: anything that must run on IE, and print work
AVIF（AV1 Image File Format）
A next-generation format built on the AV1 video codec. It compresses harder than WebP and supports HDR. Encoding is comparatively slow, but the balance of quality against file size is the best available.
- Best for: sites where size matters most, and HDR imagery
- Avoid for: old-browser support and real-time encoding
GIF（Graphics Interchange Format）
Limited to 256 colours, but it has supported animation for decades. Video and WebP/AVIF animation are steadily replacing it, yet its near-universal compatibility keeps it alive for short loops on social networks and messaging apps.
- Best for: short animations and legacy systems
- Avoid for: photographs and anything needing high fidelity — 256 colours is not enough
Recommended practice for the web
On a modern site the best practice is to offer several formats with fallbacks through the <picture> element.
<picture>
<source srcset="image.avif" type="image/avif">
<source srcset="image.webp" type="image/webp">
<img src="image.jpg" alt="説明文">
</picture>With that markup, browsers that understand AVIF get AVIF, those that understand WebP get WebP, and everything else falls back to JPEG. DevLab provides test images in each format for checking conversions and comparing sizes.