Short answer
Use JPG for photographs, where its lossy compression discards detail the eye does not miss and produces files a fraction of PNG's size. Use PNG for screenshots, logos, diagrams and anything with transparency or text, where JPG's compression creates visible smearing around hard edges.
JPG vs PNG, side by side
| Aspect | JPG | PNG |
|---|---|---|
| Photographs | Excellent — small files | Very large files |
| Screenshots and text | Visible artefacts around edges | Pixel-perfect |
| Transparency | Not supported | Full alpha channel |
| Compression type | Lossy | Lossless |
| Re-saving repeatedly | Degrades each time | No degradation ever |
| Typical photo file size | Small | 5–10× larger |
| Universal support | Yes | Yes |
Why JPG ruins screenshots
JPG compresses by discarding high-frequency detail — precisely the sharp transitions that make up text and interface edges. The result is the faint halo or smearing you see around letters in a screenshot saved as JPG. The same compression is nearly invisible on a photograph, where hard edges are rare and detail is already irregular.
This is also why a JPG degrades every time you open and re-save it. Each save runs the lossy encoder again on an already-degraded image, and the damage accumulates. PNG can be re-saved indefinitely with no loss at all.
Why PNG bloats photographs
PNG is lossless: it must reproduce every pixel exactly. Photographs contain millions of subtly different colours with no exact repetition, which leaves lossless compression very little to work with. A photo saved as PNG is routinely five to ten times larger than the same photo as JPG at a quality nobody can distinguish.
That size difference is why using PNG for photographs on a website is one of the most common causes of a slow page.
In 2026, often neither
This comparison is really about a decision made in the 1990s. WebP and AVIF both handle photographs better than JPG and support transparency like PNG, usually at a smaller size than either.
JPG and PNG still win on one thing: universal compatibility with old software and systems that were never updated. If a file has to be opened by something you do not control, they remain the safe choice.
Frequently Asked Questions
Which is better quality, JPG or PNG?
PNG is technically perfect and JPG is not, but "better quality" is the wrong frame. At sensible settings a JPG photograph is indistinguishable from the PNG original at a fraction of the size. For a screenshot, the difference is immediately visible and PNG wins outright.
Can I convert PNG to JPG without losing quality?
Not strictly — JPG is lossy, so some information is always discarded. At high quality settings the loss is imperceptible for photographs. For screenshots and graphics it will be visible, and transparency is lost entirely.
Why did my transparent PNG turn black as a JPG?
JPG has no way to store transparency, so transparent pixels have to be filled with something. Many converters silently use black. Choose a background colour before converting, or export to PNG, WebP or AVIF instead.
Which is better for printing?
Neither is ideal — printing wants a high-resolution source, and that matters far more than the format. Between the two, PNG avoids compression artefacts, but a high-quality JPG at print resolution is perfectly acceptable and much easier to handle.
Try it yourself
Terms used here
- Lossy vs lossless
- WebP
- AVIF — AV1 Image File Format
Related comparisons
- WebP vs AVIF — AVIF for the smallest files; WebP when you need guaranteed support everywhere.
- Compressing vs Resizing an Image — Resize first, then compress. Resizing does far more for file size.