Many websites and apps do not allow you to upload a photo if it does not end in .jpg (also known as jpeg). If your photo ends in .gif, .tiff, .png, or any other file extension, it can be pretty frustrating. Converting some images into jpg will result in a less sharp image. However, the format is known for its ability to maintain the best possible quality in the smallest possible file size. While you do not need to be a computer genius to turn an image into jpg, you need to learn a few tricks of the trade.
1 Open your image with Preview.  Preview is preinstalled on your Mac and opens almost any image type. Press Ctrl, at the same time click on the image and select “Open with”. Select “Preview.”
If you have an image type that you can not open or that looks wrong in the software, you can try using a web converter or Gimp.
The image must be on your computer for this method to work. If you have not yet downloaded the image to your computer, you have to do it first.
2. Click the “File” menu and select “Export”. A box appears containing several menus.
3. Change the format to jpeg. You can also adjust the quality and resolution if you want. The higher the quality or resolution, the more space the photo takes on your hard drive.
4. Rename the file and save it. Make sure the name of your file ends with “.jpg” (case insensitive), and then choose a location to remember. Click “Save” to complete the conversion.
Convert PDF to JPG online
First of all, you have to decide how you want to convert your PDF to JPG. Do you want to use an online service or do you want to install a program on your PC? You want to convert online? Then search in a search engine for the term “convert pdf to jpg online” and have a variety of providers to choose from. Choose the platform that suits you. We have tested the free tools pdf2jpg and smallpdf for you, but there are more.