How to Convert PNG to JPG (and When You Shouldn't)
To convert a PNG to a JPG, open it in Image Compress, set the output format to JPEG, leave the quality at 80%, and click Download. For a photo, the JPG is usually much smaller and looks the same. It works in your browser, so the image isn't uploaded anywhere.
Before you convert, though, check what's in the picture. JPG is great for photos and poor for screenshots, logos and anything with a see-through background. Converting the wrong kind of image gives you white boxes where transparency used to be, or fuzzy edges around text. The sections below explain how to tell which case you're in.
PNG and JPG in one minute
PNG is lossless: when the file is saved and opened again, every pixel comes back exactly as it was. It can also store transparency, meaning parts of the image can be see-through. That's why logos, icons and stickers are often PNGs.
JPG (also written JPEG, same format) is lossy: it throws away detail your eye is unlikely to notice in order to make the file smaller. On a photo of a beach or a face, that loss is hard to see. On a crisp black-on-white screenshot, it shows up as blur and faint smudges around letters. JPG has no transparency at all.
Mozilla's guide to image formats for the web gives the same advice: JPEG for photographs, PNG when you need exact reproduction or transparency.
When converting PNG to JPG makes sense
- A photo that happens to be a PNG. Some phones, screenshot tools and editing apps save photos as PNG. A photo stored as PNG is often much larger than the same photo saved as a JPG.
- An upload form that only accepts JPG. Job portals, visa applications and older websites often list "JPG/JPEG only".
- A file that's too big to email or upload. Turning a photographic PNG into a JPG is often the single biggest size cut you can make.
When you shouldn't convert
The image has a transparent background
JPG can't store transparency, so something has to fill those areas. In Image Compress, see-through parts are filled with white. A round profile picture becomes a circle on a white square. A logo cut out for a dark website gets a white box around it.
If you need to keep transparency and also want a smaller file, choose WebP in the same tool instead. WebP keeps transparency and usually gives smaller files than JPEG. The catch is that some older programs and a few upload forms still reject it.
It's a screenshot, chart or graphic with text
Screenshots, diagrams, spreadsheets and slides have sharp edges and flat areas of colour. JPG compression handles those badly, and you may see grey speckles around letters and lines. Keep these as PNG. If the PNG is too large, try reducing its width rather than switching format.
You'll keep editing it
Every time a JPG is saved again, it loses a little more detail. If you're still working on an image, keep the PNG as your master copy and only export a JPG at the end.
Step by step: convert PNG to JPG
- Open Image Compress and click the upload area to pick your PNG.
- Change the output format from WebP (the starting choice) to JPEG.
- Leave the Quality slider at 80% to begin with. For most photos you won't see a difference from the original.
- Optional: if the image is much wider than you need, type a value in Max width, such as 1600. Height scales to match, so nothing stretches. Leave it at 0 to keep the original size.
- Check the four boxes under the controls: original size, compressed size, percentage saved and final dimensions. The preview updates a moment after each change.
- Click Download. The file is saved with
-compressed added to its name, for example beach-compressed.jpg.
Picking a quality setting
80% is a good starting point. If the file still needs to be smaller, lower it in steps of 5 and watch the preview. Around 60% to 70% often still looks fine on a phone screen or in an email. Below that you may start to see blocky patches in skies and smooth skin.
If you're trying to hit a size limit, such as 500 KB on an application form, resizing usually helps more than the quality slider. A max width of 1200 to 1600 pixels is plenty for most web pages and forms.
If the JPG comes out bigger
The Saved box turns red when the new file is larger than the original. This can happen when the PNG was a small, simple graphic, such as a logo with a few flat colours. PNG compresses that kind of image very well, and JPG doesn't. It's a good sign the image should stay a PNG. You can also try a lower quality or WebP.
Quick decision table
| What's in the PNG | Best choice |
|---|
| A photo, no transparency | JPEG at about 80% |
| A photo for your own website | WebP, or JPEG if the site doesn't accept WebP |
| A logo, icon or cut-out with a transparent background | Keep PNG, or WebP to keep transparency in a smaller file |
| A screenshot, chart or anything with small text | Keep PNG |
| A form that only accepts JPG, and the image has transparency | JPEG, knowing the background will turn white |
A few practical notes
- The tool handles one image at a time. There's no batch mode.
- Max width only makes images smaller. It won't enlarge a small picture.
- Very large images can be slow on older phones, because all the work happens on your device.
- Your image is read and redrawn by the encoder built into your browser and never sent to our server. That's useful for ID scans and family photos, and there's no upload wait.
If you only need part of the picture, crop it first with Image Crop and then convert the result. Cropping away empty space also makes the file smaller.
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