PNG vs JPG: When to Use Which Format (Complete Guide)

Every time you save an image, you're making a choice that affects its quality, file size, and what you can do with it. PNG and JPG are the two most common image formats on the web, but they're designed for different jobs — and picking the wrong one can mean blurry photos or bloated files.

This guide explains what each format is, how they differ, and exactly when to use each one. It also covers how to convert between them when you need to.

What Is JPG?

JPG (or JPEG — the same format) was developed in the early 1990s specifically for photographs. It uses lossy compression, which means it discards some image data during saving in order to reduce file size.

The result: a much smaller file than the original, but with a slight reduction in quality. The more you compress a JPG, the smaller the file — and the more quality you lose. If you open, edit, and re-save a JPG multiple times, quality degrades further each time (called "generation loss").

JPG does not support transparency. If you place a JPG on a colored background, there will always be a solid rectangle behind the subject.

What Is PNG?

PNG (Portable Network Graphics) was created in 1995 as an open, patent-free alternative to GIF. It uses lossless compression, meaning no image data is discarded during saving.

This means a PNG will always look exactly like the original — no quality loss, ever. The tradeoff is larger file sizes compared to JPG at equivalent visual quality.

PNG supports a full alpha channel, which means pixels can be fully transparent, fully opaque, or anywhere in between. This is what makes PNG the standard format for logos, icons, and anything that needs to sit on top of other content without a background box.

Key Differences at a Glance

When to Use JPG

Use JPG for:

• Photographs — portraits, landscapes, product photos taken with a camera
• Images with gradients and complex color blends — JPG handles smooth color transitions efficiently
• Web images where file size matters — a well-compressed JPG is often 5-10x smaller than an equivalent PNG
• Images that will only be saved once — if you're not going to re-edit and re-save the file, the quality loss from one compression cycle is often imperceptible

A typical full-resolution photo from a smartphone might be 3-6 MB as JPG. The same photo saved as PNG could be 15-30 MB or more. For a website serving hundreds of images, this difference adds up quickly to slower load times.

When to Use PNG

Use PNG for:

• Logos and brand assets — sharp edges, text, and flat colors are preserved perfectly
• Screenshots — text in screenshots becomes blurry when saved as JPG; PNG keeps it crisp
• Images with transparency — any image that needs a transparent background must be saved as PNG
• Graphics, illustrations, and icons — synthetic images with sharp edges and flat colors benefit from PNG's lossless compression
• Images you'll edit repeatedly — because there's no generation loss, PNG is safer for working files

If you've used BestPNG to remove a background from an image, the output is always a PNG — because only PNG can preserve the transparency you just created.

The Transparency Question

This is the single most common reason people need to convert between formats:

• PNG to JPG: You want to send a photo that was accidentally saved as PNG to reduce its file size. When you convert PNG to JPG, the transparent areas will be filled with white (or a color of your choosing) because JPG cannot store transparency.
• JPG to PNG: You have a photo you want to use as a base for editing or compositing, and you want lossless quality. Converting JPG to PNG creates a perfect copy with no further quality loss on subsequent saves.

How to Convert Between PNG and JPG

BestPNG offers free, browser-based format conversion:

• Convert PNG to JPG — reduces file size, fills transparent areas with white
• Convert JPG to PNG — preserves quality, enables future transparent edits
• General format converter — supports PNG, JPG, WEBP, AVIF, and more

All conversions happen in your browser. No upload to a server, no file size limits, no sign-up required.

Common Misconceptions

"PNG is always better quality than JPG"

Not exactly. A JPG at high quality settings can be visually indistinguishable from the original photo at a fraction of the file size. For photographs, high-quality JPG is often the right choice. PNG's lossless advantage matters most for text, sharp edges, and repeated editing.

"I should always convert my photos to PNG for quality"

For a photo you're just viewing or sharing, converting from JPG to PNG doesn't recover quality that was already lost in the original JPG compression. It just creates a larger file. PNG is better for future editing, not for recovering past compression.

"JPG and JPEG are different formats"

They're identical. JPEG is the full name (Joint Photographic Experts Group); JPG is the three-character file extension used historically on Windows. Same format, same files.

Quick Decision Guide

Ask yourself:

1. Does this image need a transparent background? → PNG
2. Is this a photograph or complex photo? → JPG (at quality 80-90)
3. Is this a logo, icon, or screenshot? → PNG
4. Am I trying to reduce file size for the web? → JPG (or WEBP if supported)
5. Will I keep editing and re-saving this file? → PNG

Conclusion

JPG and PNG serve different purposes. JPG is the right tool for photographs and web images where file size matters. PNG is essential for transparency, graphics, logos, and anything where perfect quality must be preserved across edits.

When you need to move between formats, BestPNG's free conversion tools make it effortless:

• Convert PNG to JPG →
• Convert JPG to PNG →
• All format conversions →