PNG and JPG are the two most common image formats. Most people use them interchangeably — and then wonder why their photo looks blurry or why their logo has a white box behind it. The choice actually matters, and it's not complicated once you understand what each format is designed for.
The core difference: how they handle compression
JPG (JPEG) uses lossy compression. It permanently discards some image data to make the file smaller. The algorithm targets information your eyes are least likely to miss — subtle color gradations in complex scenes. For a photograph of a landscape, you'd struggle to spot the difference between the original and a high-quality JPG. But run the same image through JPG compression ten times and the degradation becomes visible. Every time you save a JPG, you lose a little more.
PNG uses lossless compression. Every pixel is preserved exactly. No data is discarded, no matter how many times you save the file. PNG files are larger as a result, but they're perfect — identical to the source.
When to use JPG
Use JPG for photographs and complex, high-color images where perfect pixel accuracy isn't needed.
- Portrait photos
- Product photography
- Travel and landscape shots
- Any image with continuous color gradients
JPG's compression algorithm is optimized for this type of content. A well-compressed JPG photo at 80% quality might be 5–10× smaller than the same image as a PNG, with no visible difference to most viewers. For web pages, this is the right default.
Don't use JPG for: - Images with text (compression artifacts make text look soft) - Graphics with hard edges or flat colors (the artifacts become obvious) - Logos, icons, or diagrams - Anything you'll be editing and re-saving repeatedly
When to use PNG
Use PNG for graphics, screenshots, logos, and anything requiring transparency.
- Logos with transparent backgrounds
- UI screenshots and interface mockups
- Icons, illustrations, and diagrams
- Text-heavy graphics (infographics, slides saved as images)
- Images where you need pixel-perfect preservation
PNG handles hard edges and flat color fills without any artifacting. A PNG logo has clean, sharp edges regardless of what background you place it on. JPG would add a halo of compression noise around the same shape.
PNG also supports alpha transparency — pixels can be fully transparent, fully opaque, or anything in between. JPG supports no transparency at all. If you need transparency, PNG (or WebP) is your only option among the classic formats.
Side-by-side comparison
| Property | JPG | PNG |
|---|---|---|
| Compression | Lossy (data discarded) | Lossless (data preserved) |
| Best for | Photos | Graphics, logos, screenshots |
| Transparency | No | Yes |
| File size (photos) | Small (baseline) | 150–200% of JPG |
| File size (graphics) | Often larger than PNG | Compact for flat-color images |
| Quality on re-save | Degrades each time | Perfect regardless |
| Text rendering | Poor (blurry edges) | Excellent |
The common mistakes
Using PNG for photos on a website. A 4MB PNG photo vs a 400KB JPG — same perceived quality, 10× the bandwidth. This kills page load time.
Using JPG for logos. White halos, blurry text, compression noise around clean edges. Always use PNG or SVG for logos.
Using JPG as an archive format. If you re-export the same JPG multiple times as you edit a photo, quality compounds downward. Archive originals as TIFF, PNG, or RAW. Export to JPG only for the final delivery version.
How to convert between formats
If you have an image in the wrong format, Converthor can convert it without any software:
- JPG to PNG — for adding transparency support or archiving
- PNG to JPG — for reducing photo file size before sharing
- PNG to WebP / JPG to WebP — for web use where you want both small size and quality
Conversion takes seconds and no account is required.
Quick decision rule
One question: does the image have a transparent background, hard edges, text, or is it a logo/screenshot?
- Yes → PNG
- No, it's a photo → JPG (or WebP for web use)
That rule covers 95% of cases. When in doubt, PNG is the safer choice — you can always convert a PNG to JPG later without losing the original. Going the other way discards whatever the JPG already lost.