Ever saved an image and wondered whether to choose JPEG or PNG? This guide explains the differences between the two formats in terms of compression, quality, and use cases. It also covers GIF, TIFF, and other formats so you can confidently pick the right one every time.
Key Differences Between JPEG and PNG
JPEG and PNG are both widely used image formats, but they work in fundamentally different ways.
| Feature | JPEG | PNG |
|---|---|---|
| Compression | Lossy | Lossless |
| Transparency | Not supported | Supported |
| File size | Tends to be smaller | Tends to be larger |
| Best for | Photos, gradients | Illustrations, diagrams, screenshots |
| Color depth | About 16.7 million colors | About 16.7 million colors + alpha channel |
| Re-save degradation | Yes (degrades each time) | None |
The key distinction is the compression method. JPEG uses lossy compression, sacrificing some quality to achieve much smaller file sizes. PNG uses lossless compression, preserving every pixel of the original image. This difference drives when each format is the better choice.
Quality Comparison: Photos vs Illustrations
Why JPEG Works Best for Photos
Photos contain smooth gradients with neighboring pixels that are similar in color. JPEG's lossy compression handles these gradual transitions efficiently, producing files that look nearly identical to the original at a fraction of the size.
Saving the same photo as PNG can result in a file 3 to 5 times larger than JPEG. For web display and email, JPEG is the practical choice for photos.
Why PNG Works Best for Illustrations and Diagrams
Illustrations and diagrams have sharp color boundaries and large areas of solid color. When saved as JPEG, these sharp edges develop "mosquito noise" — a blurring artifact that makes text and lines look fuzzy.
PNG's lossless compression preserves crisp edges perfectly. And since solid-color areas compress very efficiently in PNG, file sizes for illustrations stay reasonable.
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Understanding JPEG and PNG characteristics helps with print choices too:
- Photo printing: JPEG is standard, but save at 90-100% quality. Low-quality JPEG shows visible block artifacts in print
- Logo and illustration printing: PNG is better — crisp edges produce sharp text and logo outlines
- Transparent backgrounds: PNG only. JPEG does not support transparency
JPG vs JPEG: Are They the Same?
Yes, JPG and JPEG are exactly the same format. The formal name is JPEG (Joint Photographic Experts Group), but older Windows systems limited file extensions to 3 characters, creating the .jpg shorthand.
Today, .jpg and .jpeg produce identical results with no difference in quality or file size. Web convention tends to favor .jpg, while macOS screenshots often use .jpeg.
How GIF, TIFF, and BMP Compare
Beyond JPEG and PNG, several other image formats serve specific purposes:
| Format | Compression | Colors | Transparency | Primary Use |
|---|---|---|---|---|
| JPEG | Lossy | About 16.7M | No | General photography |
| PNG | Lossless | About 16.7M + alpha | Yes | Illustrations, screenshots |
| GIF | Lossless | Max 256 | Yes | Animations, simple icons |
| TIFF | None/Lossless | About 16.7M+ | Yes | Printing, medical, publishing |
| BMP | None | About 16.7M | No | Windows legacy |
- GIF: Limited to 256 colors, so it is unsuitable for photos. Best for short animations and simple icons
- TIFF: Maintains maximum quality with no compression or lossless compression, but files are very large. Used in printing, publishing, and medical imaging
- BMP: No compression means the largest file sizes. Rarely used today
Quick Reference: Best Format by Use Case
| Use Case | Best Format | Why |
|---|---|---|
| Website photos | JPEG (or WebP) | Small files, fast loading |
| Website illustrations/logos | PNG | Crisp edges, transparency support |
| Social media photos | JPEG | Universal device compatibility |
| Screenshots | PNG | Text and UI details stay sharp |
| Email attachments | JPEG | Stays within size limits easily |
| Photo printing | JPEG (high quality) | Sufficient quality at reasonable size |
| Logo/diagram printing | PNG | Sharp outlines preserved |
| Animations | GIF (or MP4) | Supports motion |
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Try it now →FAQ
Which has better quality, JPEG or PNG?
For the same image, PNG delivers higher quality because lossless compression preserves every detail. JPEG degrades slightly with each save. That said, JPEG at 80-90% quality is visually indistinguishable from the original for photos, and the file size is dramatically smaller.
What happens when you save an illustration as JPEG?
You may notice blurring (mosquito noise) around color boundaries, making lines and text look fuzzy. This is especially visible in illustrations with solid colors and thin lines — PNG is the better choice for these.
Does converting between JPEG and PNG improve quality?
Converting JPEG to PNG will not restore quality lost during JPEG compression — it just increases file size. Converting PNG to JPEG reduces file size but introduces some quality loss. Neither conversion can undo previous compression artifacts.
Should I use JPEG or PNG for websites?
Use JPEG for photos, PNG for illustrations, logos, and screenshots. WebP is also worth considering as it is about 30% lighter than JPEG and widely supported. sakutto's image compressor can convert to WebP right in your browser.
Summary
Understanding the difference between JPEG and PNG lets you choose the right format without second-guessing. Photos go with JPEG; illustrations and diagrams go with PNG. When you need to reduce file size further, an online compression tool can help while preserving visual quality.
Free Tool
Image Compressor
Compress JPEG, PNG, WebP, and HEIC images. Adjust quality, remove Exif data, and convert formats.
Try it now →