How to Convert PNG to JPG and Vice Versa?

PNG and JPG are two dominant image formats available on the web. Though there are many other formats like BMP, GIF, TIFF and WebP, people prefer to use JPG or PNG formats. There are three reasons for the popularity of these two image formats – optimal size, quality and browser / application support. If you are looking for converting PNG to JPG or JPG to PNG, here are the options for you.

PNG and JPEG Image Formats

PNG stands for Portable Network Graphics and used by bloggers and web designers to publish pictures on the web.

• PNG uses lossless compression hence the size of the image tends to be higher.
• You can create transparent background images with PNG format.
• It is not possible to adjust the compression quality and hence the image size.
• PNG is an improved version developed to replace GIF image format.

JPEG stands for Joint Photographic Experts Group and uses .jpeg, .jpg, .jpe or .jfif file extensions.

• Most used by digital photographers.
• Uses lossy compression and hence you can adjust the quality and size.
• Not transparent.

You can get more details of PNG and JPEG formats in corresponding Wikipedia pages.

How to Convert PNG to JPG and Vice Versa?

In many situations, you may want to convert one image format to other. For example, a simple desktop screenshot in PNG format will be in few MB size while you can convert the same screenshot to JPG format with few hundred KB size. On other hand, PNG’s transparent background is suitable for images published on websites having different background colors. Here are some of the options to convert PNG to JPG and vice versa.

• Use Paint 3D in Windows
• Using Preview in Mac
• Third-party tools like SnagIt or Photoshop
• Adobe Photo Express in Mobile
• Using online tools
• Change the file extension
• Save screenshots as PNG or JPG

1. Using Paint 3D to Convert Image Format in Windows

By default, Windows will open all images in Photos app. However, you can open the picture in Paint 3D to convert from PNG to JPG and vice versa.

• Right click on the image and choose “Open with > Paint 3D”.

Alternatively, you can open the image from Paint 3D by going to “Menu > Open”.

• After opening the image, go to “Menu” and select “Save as” option.
• On the right pane, choose “Image”.

• On the “Save As” dialog box that appears, select “2D – JPEG” or “2D – PNG” from “Save as type:” dropdown.

This way you can convert the image format using Paint 3D app in Windows 10. In fact, you can also change the image to other formats like BMP, GIF or TIFF. If you are saving an image with 3D objects, Paint 3D offers you to choose the file format from one of the available options like PNG or JPG on the sidebar.

File Size Difference

Using Paint 3D, a simple screenshot picture converted from 266 KB JPG is with the size of 425KB PNG. This is almost 60% increase in the size.

Alternatively, when we convert the same PNG back to JPG, it is of 100KB in size. That is more than 76% reduction in size. Unfortunately, Paint 3D does not offer option to select the compression quality for JPG images. This means JPG image is with 100% quality, which will have no difference with huge PNG image.

Whether you are a web publisher or digital photographer, showing an image on a website with +75% reduced size is a great deal. This will help to speed up the page loading speed with the same quality of image.

2. Use Mac Preview App

If you are using Mac, you have a Preview app better than the Paint 3D in Windows.

• Open your image in Preview.
• Go to “File > Save As…” or “File > Export” menu.

• Choose “JPEG” or “PNG” as format. Preview app also offers JPEG-2000 or HEIC formats to reduce the size.

• When you select JPEG as format, you can setup the quality between least to best. The advantage here is that you can get the size of the image instantly based on your quality choice.

3. Third-party Tools like SnagIt or Photoshop (Windows & Mac)

As mentioned, Paint 3D and many other applications do not offer a way to choose the compression quality for JPEG images. In addition, many applications do not support transparent PNG, though you can convert the images. There are many third-party tools help to overcome these problems and have a perfect solution.

If you are a web publisher, we recommend using premium tools like SnagIt and Photoshop is suitable app for designers. Here we will explain converting images in SnagIt.

• Open your images with SnagIt.
• Go to “File > Save As” menu.
• Choose the required PNG or JPG format for your image.

• Click on the “Options…” button.
• For a PNG image, you can choose the color quality.

• For a JPG image, you can choose the compression quality, colors and subfile type.

If you are using SnagIt for Mac, you can change the compression quality when saving the file.

4. Converting PNG to JPG in Mobiles

Default Windows and Mac applications are best on desktop but not available on mobile devices. Though SnagIt is popular, it also does not have mobile app. Therefore, the left over and the best option is to use Adobe Photoshop Express Photo Editor app.

• Take a screenshot or open an image in Photo Express app. In the below example, the PNG image is of 9.34 MB size.
• Click on the share button in the app and tap on the image format to choose JPEG. You can also change the compression quality and we set it as 85%.
• Save our image and open it in the app. As you can see the JPEG image is of 655.46 KB in size.
• This is almost 99% reduction in size without much difference in quality. You should really use this app to convert all your PNG images to JPEG to save storage space on your smartphone.

You can convert JPG to PNG and vice versa when saving your images with this app. In addition, Photo Express offers bunch of other features for creating wonderful pictures on Android and iOS platforms.

5. Using Online Tools

If using app is not an option for you, especially on mobiles, you can try free online tools for image conversion.

• Go to PNG2JPG website.
• Click on “JPG to PNG” or “PNG to JPG” tab and upload you image. You can also upload multiple images at once for conversion.

• Click on “Download” or “Download All” button.
• Converted image files will be downloaded as “png2jpg.zip” file in the default download location you setup in the browser.
• Extract the zip file and use your converted images.

We have converted the same PNG image of 425KB size and the converted JPG image size with this tool is only 75KB in size. The advantage with online tools is that you can bulk convert images with single click.

Remember not to upload personal or confidential images in public websites. Though png2jpg site claims all uploaded data is deleted every hour, it is not a good idea to upload important images. We strongly recommend purchasing a premium tool for using important files, as you can convert images on your devices without uploading to third party sever.

6. Changing File Extension

Well, you may wonder what will happen if you simply change the file extension to PNG or JPG.

• Open File Explorer and go to your image file.
• Under “View” menu, select “File name extensions” under “Show/Hide” group.
• This will show the file extensions of your images.
• Click on the image or press F2 after highlighting the image to rename it.
• Change the file extension from PNG to JPG or vice versa and press enter key.
• Windows will show you a warning message and click “Yes” to confirm the file extension change.

Now, open the image to see it will open with the default image processing tools like Photos. You can follow the similar process to change the file extension in Mac also.

Unfortunately, changing the file extension may cause problems when open the images in different applications. In addition, the size of the image will not change. We recommend you to convert the images in proper way to save the size or increase the quality.

7. Save Screenshots in PNG or JPG Format

As mentioned above, you can use SnagIt for screen capture in both Windows/Mac and Photo Express in mobile. In addition, there are many free tools available that you can use to capture images and save in either PNG or JPG format. Below is an example of WinSnap tool that allows you to choose the file extension when saving the screenshot image.

If you prefer to use the default screen capture tools – use Snip & Sketch in Windows and Screenshots app in Mac. Snip & Sketch tools offers option to toggle the image formats between PNG or JPG format while saving. However, on Mac you have to either change the format of saving from PNG to JPG or use Preview to open the image for conversion. There are no options to select PNG or JPG when saving.