For a photograph, start with JPG or WebP. For a screenshot, diagram, logo, or image that needs transparency, start with PNG or lossless WebP. The best format is the smallest file that preserves the visual details and features your use case requires.
JPG, PNG, and WebP compared
| Format | Compression | Transparency | Best fit |
|---|---|---|---|
| JPG / JPEG | Lossy | No | Photographs, email, and broad compatibility |
| PNG | Lossless | Yes | Screenshots, diagrams, text, logos, and editing masters |
| WebP | Lossy or lossless | Yes | Modern websites needing compact delivery files |
When JPG is the right choice
JPG uses lossy compression, which discards some image information to reduce file size. That tradeoff works especially well for photographs, where gradual color and tone changes can hide moderate compression.
Choose JPG when the image is photographic, recipients may use older software, or a simple universally recognized file is more important than transparency. Avoid repeatedly opening and resaving a JPG at low quality because each lossy export can introduce additional artifacts.
When PNG is the right choice
PNG uses lossless compression and supports an alpha channel for transparency. It is usually a safer choice for screenshots with text, interface captures, diagrams, logos, and graphics with hard edges.
A photograph saved as PNG can be dramatically larger than an equivalent JPG without a useful visible benefit. Preserve PNG for cases where its exact reproduction or transparency is actually needed.
When WebP is the right choice
WebP supports both lossy and lossless compression as well as transparency. MDN recommends it as a strong option for modern web imagery because it can deliver better compression than older formats while supporting a broad feature set.
WebP is widely supported by current browsers, but a JPG or PNG may remain more convenient for older desktop applications, external editing workflows, or recipients who expect a familiar format.
Optimize for the real delivery context. WebP is often an excellent website output; keep a high-quality source separately so future resizing and conversion do not depend on an already compressed derivative.
A simple format decision
Does it need transparency?
Choose PNG or WebP. A JPG export must replace transparent pixels with a solid background.
Is it a photograph?
Choose JPG for maximum familiarity or lossy WebP for modern web delivery.
Does it contain small text or sharp lines?
Choose PNG or lossless WebP to avoid fuzzy compression artifacts around edges.
Is download performance the priority?
Test WebP and compare the output at the actual displayed dimensions rather than choosing by extension alone.
Convert, resize, then compress
A dependable workflow is to keep the best available source, resize it to the largest dimensions actually needed, select the appropriate output format, and then adjust quality while inspecting the result.
Frequently asked questions
Is PNG always higher quality than JPG?
PNG preserves image data with lossless compression, but that does not make it the best format for every image. Photographs usually achieve much smaller files with JPG or lossy WebP at an acceptable visual quality.
Which format supports a transparent background?
PNG and WebP support transparency. JPG does not, so transparent areas must be filled with a solid color when exporting to JPG.
Should I convert every website image to WebP?
WebP is a strong default for many modern websites, but requirements such as editing workflows, archival quality, compatibility, and transparent graphics should still guide the choice.
Primary reference
- MDN: Image file type and format guide — format features, browser support, and use-case recommendations.