Efficient Image Formats
JPEG, WebP, AVIF and PNG – selected according to file size, transparency and compatibility.
Why Format Influences Performance
Images often account for the largest share of a website’s data volume. The file format determines how efficiently an image is stored and delivered.
Depending on the format, the following factors vary:
- File size and loading speed
- Detail retention and compression behaviour
- Transparency for cut-outs and overlays
- Browser and system compatibility
Format selection is therefore not merely an export setting, but part of a stable web structure.
Three Criteria That Matter in Practice
Compression & Detail
JPEG uses lossy compression and remains reliable for classic photographic motifs. WebP and AVIF often achieve significantly smaller file sizes at comparable visual quality. PNG is lossless but generally produces much larger files.
Transparency & Cut-Outs
PNG, WebP and AVIF support transparency. This is relevant for cut-outs, UI-related imagery, overlays or hybrid layouts.
Compatibility & Infrastructure
Not every system processes every format equally. CMS platforms, online shops, image CDNs and browser support determine which formats are appropriate – and how they should be delivered.
Example: File Size at 1200 px Width
At comparable visual quality, typical tendencies are:
- JPEG: approx. 250–400 KB
- WebP: approx. 150–250 KB
- AVIF: sometimes below 150 KB
- PNG: significantly larger at the same resolution
Actual values depend on the subject matter (detail, texture, edges) and compression settings. However, these comparisons illustrate how strongly format choice can influence PageSpeed and mobile loading times.
| Format | Compression | Transparency | File Size | Typical Use |
|---|---|---|---|---|
| JPEG | Lossy | No | Medium | Classic photography |
| WebP | Efficient | Yes | Small | Modern websites, CMS |
| AVIF | Highly efficient | Yes | Very small | Performance-focused projects |
| PNG | Lossless | Yes | Large | Cut-outs, graphics, UI-related imagery |
Format Selection as Part of the Overall Strategy
The appropriate format depends not only on the image itself, but on its intended use.
At Shutterwerk, format selection is therefore defined within context: website performance, system environment, transparency requirements and long-term scalability.
The result is image data that functions technically – and remains visually stable.
Additional Note: Colour Space & Multi-Use
For web projects, sRGB is typically used to ensure consistent colour rendering across devices. If images are also required for print or presentations, separate versions are prepared accordingly.
Contact
If image formats are to be not only compatible, but strategically aligned with your website,
