JPG vs PNG — Which Image Format Should You Choose?
Compare JPG and PNG image formats. Understand compression, transparency, file size, and which format is best for photos, graphics, and web use.
| Feature | JPG (JPEG) | PNG |
|---|---|---|
| Compression Type | Lossy | Lossless |
| Transparency | No | Yes (full alpha) |
| File Size (photos) | Small | Very large |
| File Size (logos/icons) | Often larger than PNG | Smaller |
| Quality Loss on Save | Yes, cumulative | None |
| Text in Images | Blurry/artifacted | Crisp |
| Best Use Case | Photos, realistic imagery | Logos, icons, screenshots |
| Animation | No | No (standard PNG) |
Verdict
Use JPG for photographs and images with complex colors and gradients where some quality loss is acceptable. Use PNG for logos, icons, screenshots, and any image requiring transparency or sharp text. For modern websites, consider WebP which delivers better compression than both.
Understanding Lossy vs Lossless Compression
The fundamental difference between JPG and PNG is compression philosophy. JPG uses lossy compression (specifically the Discrete Cosine Transform) which discards some image information to achieve small file sizes. The algorithm divides the image into 8x8 pixel blocks and discards high-frequency detail that human vision is less sensitive to. For photographs with smooth color transitions, this works beautifully — files 5-20x smaller than PNG with barely noticeable quality loss. For images with sharp edges and text, the same algorithm creates ugly blocking artifacts around boundaries. PNG uses DEFLATE (lossless) compression which reorganizes pixel data for compactness without discarding any information, producing perfect reproduction at the cost of larger files.
When Transparency Changes Everything
PNG's alpha channel transparency is often the deciding factor for logos and UI elements. A PNG logo with a transparent background can be placed on any colored surface and look correct — the logo appears to float on the page. The JPG equivalent must have a specific background color baked in, looking awkward if the page background is different. For app icons, product images with transparent backgrounds (e-commerce), watermarks, and overlay graphics, PNG (or WebP) is the only practical choice. This single feature explains why designers always deliver logos as PNG files rather than JPG.
The WebP Alternative
WebP, developed by Google, offers better compression than both JPG and PNG for their respective use cases. For photographs, WebP achieves 25-35% smaller files than JPG at equivalent visual quality. For graphics with transparency, WebP-with-alpha is typically 20-30% smaller than PNG-24. WebP also supports animation (unlike static PNG and JPG). All modern browsers support WebP. The practical recommendation for new web projects is to use WebP as the primary format, use responsive images with <picture> elements to serve WebP with JPEG fallbacks for older browsers, and retain PNG for images that need lossless preservation or maximum compatibility in non-browser contexts.
Frequently Asked Questions
No. Converting a JPG to PNG only prevents further quality loss on future saves — it cannot recover detail lost during the original JPG compression. The PNG will be losslessly stored but at the JPG's already-degraded quality. Always keep originals in lossless format (PNG, TIFF, RAW) before converting to JPG.
Screenshots contain sharp edges, solid color regions, text, and UI elements that JPG compression handles poorly. The lossy compression creates ringing artifacts around sharp edges and color banding in flat regions. Screenshots should always be saved as PNG for crisp, artifact-free results.
For modern websites, WebP is better than both — it offers superior compression for both photographic and graphic content, supports transparency, and is supported by all modern browsers. Use WebP as the primary format with JPG/PNG fallbacks for older browsers.
For web use, 70-85% quality provides a good balance of size and visual quality. At 80%, most viewers cannot distinguish JPG from the original without careful side-by-side comparison. Quality below 60% produces visible artifacts. Quality at 90%+ produces large files without meaningful visual improvement.