PNG and JPG solve different problems. PNG is lossless — every pixel is stored exactly, which makes it the right format for graphics, logos, screenshots, and images where crisp edges and exact colour values matter. JPG uses lossy compression to achieve much smaller file sizes, which makes it the right format for photographs and complex images where minor quality loss is imperceptible and file size is a real constraint.
The reason to convert PNG to JPG is almost always file size. A photograph saved as PNG can be five to ten times larger than the same image as a JPG at comparable visual quality. For web use, email, or any context where file size affects load times or hits upload limits, that difference matters.
When the conversion makes sense
PNG to JPG is the right conversion for photographic content — images with gradients, complex colour variation, and continuous tones. These are exactly the images JPG's compression handles well. The areas where JPG compression introduces visible artefacts are high-contrast edges between flat colours and fine text, which are more common in graphics and screenshots than in photographs.
If the PNG contains a logo, icon, screenshot, diagram, or any image with flat colours, crisp lines, or text, converting to JPG will likely produce visible compression artefacts at those boundaries. For those images, PNG — or WebP in lossless mode — is the better format regardless of file size concerns.
If the PNG has a transparent background, JPG can't preserve it. The transparent areas will be filled with a solid colour (usually white by default) during conversion. If you need transparency to remain, stay with PNG or use WebP, which supports transparency at smaller file sizes than PNG.
Converting with Portimg
Go to portimg.com/raster-to-raster-converter, upload your PNG file or files, select JPG as the output format, and download. Batch uploads are supported. No account required, files deleted after processing.
The quality setting determines the tradeoff between file size and visual fidelity. For web use, 80–85% quality produces output that's visually indistinguishable from higher settings at normal screen sizes while achieving meaningful file size reduction. Going above 90% produces larger files with no visible improvement. Going below 75% starts to introduce noticeable artefacts, particularly in areas with fine detail.
Keep the original PNG. The conversion from lossless PNG to lossy JPG is permanent — the quality loss can't be recovered, and the JPG can't be converted back to a lossless format. If there's any chance you'll need the original for print, editing, or future use at a different quality setting, keep it.
A better alternative for web use
If the image is going onto a website, it's worth considering WebP rather than JPG as the conversion target. WebP produces files roughly 25–35% smaller than JPG at equivalent quality, supports transparency like PNG, and is supported by all major browsers. For new web content, converting PNG to WebP gives you the file size benefits of JPG without the transparency limitation and with better compression.
JPG remains the better choice when compatibility with unknown software matters — email clients, older applications, file sharing with recipients whose setup you don't know. For those situations, JPG's near-universal support makes it the safer default over WebP.
Portimg's converter handles both PNG to JPG and PNG to WebP, so you can choose the right output for where the image is going.