Why is my PNG so much larger than a JPG of the same image?

PNG is a lossless format - It stores every pixel exactly, producing large files that are often unnecessary for photographs and detailed imagery. Converting PNG to JPG applies JPEG's lossy compression, which can reduce file size by 50–80% for photographic content. This matters for website performance, email attachments, and cloud storage limits.

The critical caveat is transparency. PNG supports transparent pixels; JPEG does not. When you convert a PNG with transparent areas to JPG, those areas must be filled with a solid background colour - White by default. If your design depends on transparency (logos on coloured backgrounds, cutout images), converting to JPG will break the intended effect. Keep transparent graphics as PNG or convert to WebP.

For photographic PNG files without transparency - Screenshots, scanned documents, digital artwork saved as PNG - JPG conversion typically delivers excellent results at quality 85%+. The JPEG encoder handles continuous-tone images efficiently, and the resulting files load faster on web pages and take up less email quota.

Reasons to convert PNG to JPG usually come down to compatibility, file-size, or specific feature requirements. Common situations:

• An app or platform only accepts JPG uploads.
• You need a feature unique to JPG (e.g. transparency, vector scaling, animation, multi-page pages, etc.) that PNG doesn't provide.
• You're optimising file size — modern formats often produce smaller files than the older format you started with.
• You need a single archival format across a project so files behave consistently in the same viewer.

1. Open the PNG → JPG tool on jpg.now.
2. Drag your PNG file onto the drop zone, or click Select files. You can drop a whole folder of files at once.
3. The output is fixed to JPG. If the format supports extra options (page size, transparency background, quality, EXIF stripping), tweak them in the right-hand panel.
4. Click Convert. The job runs on our server and finishes in a few seconds for typical photos.
5. Download the result. Files stay in storage for 24 hours and are then permanently deleted.

The entire flow is free for the first 10 jobs per day with no signup required. A free account doubles that quota; a premium plan removes the limit entirely.

• Use quality 85–90% for the best balance of size and quality when converting photographic PNG images.
• Check for transparency before converting - If your PNG has a transparent background, set the background fill colour to match your intended use (white for documents, a matching colour for web designs).
• Converting UI screenshots (with text and sharp edges) to JPG can introduce blurring around text - Keep these as PNG for crisp output.
• For web publishing, consider converting to WebP instead of JPG for even better compression while avoiding the transparency issue.