JPG and PNG are the two most common image formats on the web, but they use fundamentally different compression approaches — which makes them suited to different situations.
The Core Difference
JPG (JPEG) uses lossy compression. When an image is saved as JPG, the algorithm discards some image data — primarily in colour transitions and fine detail — to reduce file size. The more you compress, the more data is lost and the more visible the compression artifacts become.
PNG uses lossless compression. Every pixel is preserved exactly as it was in the original. The file may be larger, but there is no quality loss.
Side-by-Side Comparison
| Feature | JPG | PNG | |---|---|---| | Compression type | Lossy | Lossless | | Transparency support | No | Yes (alpha channel) | | Typical file size | Smaller | Larger | | Best for | Photographs | Graphics, text, screenshots | | Quality loss | Yes (adjustable) | None | | Colour depth | 24-bit RGB | 24-bit RGB or 32-bit RGBA | | Maximum colours | 16.7 million | 16.7 million (plus alpha) | | Animation support | No | No (use GIF or WebP) |
When to Use JPG
Choose JPG when:
- The image is a photograph with complex colour gradients
- File size is a priority (for web pages, email attachments, social media)
- Transparency is not needed
- The image will be displayed at a fixed size (resizing a JPG doesn't improve quality)
Examples: Travel photos, product photos, portrait photography, food imagery, any photographic content on a website.
When to Use PNG
Choose PNG when:
- The image contains text, numbers, or fine detail that must remain sharp
- Transparency is required (logos on different backgrounds, UI elements)
- The image is a screenshot or diagram
- The image will be edited multiple times — each save as JPG degrades quality; PNG does not
- The image has flat areas of colour (logos, illustrations, charts)
Examples: Company logos, icons, UI screenshots, diagrams, charts, illustrations with flat colours.
The Quality-File Size Trade-off for Photographs
For photographs, JPG usually wins on file size with acceptable quality loss:
| JPG quality | Approximate file size reduction vs PNG | |---|---| | 90% (high) | 60-75% smaller | | 75% (medium-high) | 80-85% smaller | | 60% (medium) | 85-90% smaller |
At 90% JPG quality, most photographs are visually indistinguishable from the PNG version, but 60-75% smaller.
PNG vs JPG for Screenshots
Screenshots almost always benefit from PNG:
- Screenshots typically have sharp text, UI elements with flat colours, and precise pixel edges
- JPG compression introduces visible "blockiness" around text and sharp edges (called ringing artifacts)
- The difference between a JPG screenshot and PNG screenshot is immediately visible
Converting Between JPG and PNG
You can convert between formats using Image Converter. Keep in mind:
- PNG → JPG: Loses the lossless quality guarantee; file gets smaller; any transparency becomes a solid background colour (typically white)
- JPG → PNG: Gets larger; does not recover lost quality; transparency is not added
Related guides: JPG vs WebP · How to Convert Images Between Formats