A complete side-by-side comparison of JPG and PNG — file size, quality, transparency, and the best use case for each format.
JPG was designed for photos — it compresses photographic detail efficiently, producing small files that still look great. PNG was designed for graphics — it preserves sharp edges, text, and flat colors perfectly, and is the only common web format that supports transparency. Choosing the wrong format leads to either bloated files (PNG for photos) or ugly compression artifacts (JPG for logos).
| Feature | JPG / JPEG | PNG |
|---|---|---|
| Compression type | Lossy — some data discarded | Lossless — all data preserved |
| File size (photos) | Small — 5–20x smaller | Large — 3–5x bigger |
| File size (graphics) | Often larger due to artifacts | Compact for simple graphics |
| Transparency | Not supported | Full alpha transparency |
| Compression artifacts | Visible at low quality settings | None — lossless |
| Color depth | 24-bit (16.7M colors) | Up to 48-bit + 8-bit alpha |
| Animation | Not supported | APNG only (limited support) |
| Browser support | Universal | Universal |
| Best for | Photographs, backgrounds, hero images | Logos, icons, UI, screenshots, text |
| Re-editing quality | Degrades with each save | No degradation ever |
JPG uses a technique called Discrete Cosine Transform (DCT) to divide an image into 8×8 pixel blocks and discard fine frequency detail that the human eye is less sensitive to. This is why JPG compression works so well on photos — our visual system already averages out subtle gradients. At quality 85%, a JPG file is roughly 10x smaller than an equivalent uncompressed image, and most viewers cannot spot the difference.
The drawback appears at hard edges, text, and sharp color transitions. JPG compression creates "ringing" artifacts — blurry halos around crisp lines. This is why logos and screenshots look terrible as JPG at anything below quality 95%, which at that point defeats the size advantage entirely.
Every time you open and re-save a JPG, another round of compression is applied on top of the previous one. Over multiple edits this causes visible quality degradation — the famous "JPG generation loss" problem. If you're editing an image, work in PNG or RAW and only export to JPG as a final step.
PNG uses lossless compression — specifically a combination of a filtering algorithm followed by DEFLATE compression (the same algorithm used in ZIP files). Because no data is discarded, a PNG can always be decompressed back to the exact original pixel values. This makes PNG perfect for any image that will be edited or re-saved repeatedly.
PNG compression works best on images with large flat areas of a single color, geometric patterns, and sharp edges — exactly the characteristics of logos, icons, and UI screenshots. Photographs, with their complex natural gradients and random pixel variation, compress very poorly with PNG, producing files far larger than equivalent JPG.
PNG also supports full alpha transparency at 8 bits per pixel — each pixel can have any opacity from 0 (fully transparent) to 255 (fully opaque). This makes PNG the standard for any web graphic that needs to sit over a colored or patterned background.
There is no universally "better" format — JPG and PNG solve different problems. The rule of thumb is simple: if you're working with a photograph, use JPG. If you're working with a graphic, logo, icon, or anything with transparency, use PNG.
If you need to switch between the two — converting a photo saved accidentally as PNG, or converting a logo to PNG for transparent overlay — ImgSwift handles the conversion instantly in your browser without uploading your file to any server.
JPG is better for photos. It uses lossy compression that reduces file size dramatically while preserving enough quality that the difference is invisible at normal viewing sizes. PNG applied to photos produces files 3–5x larger with no perceptible quality benefit.
PNG is better for logos and icons. It supports transparency, uses lossless compression to preserve crisp edges, and avoids the compression artifacts that JPG introduces around sharp lines and text.
Converting JPG to PNG will not add any further quality loss — PNG is lossless so it preserves exactly what the JPG contained. However, it cannot recover detail that was already lost when the JPG was originally compressed. The resulting PNG will simply be a lossless copy of the JPG's current state.
JPG nearly always produces smaller files for photographic images, often 5–10x smaller than equivalent PNG. For simple graphics with few colors and large flat areas, PNG can sometimes be smaller than JPG, but for photos JPG wins every time.
Yes. PNG supports full alpha transparency (8-bit), meaning each pixel can be fully transparent, fully opaque, or any level of semi-transparency in between. JPG has no transparency support at all — it always has a solid background.