1. Enlarge the image
If you want to follow the “letter of the law,” then you can simply put your JPEG or PNG image into an image-editor and blow it up. This will give you a larger image, but it won't enhance the quality because you're just blowing up pixels.
Some image-editors are better than others at enlarging and enhancing details. But remember that this isn't Hollywood and your image still won't look as good as if you follow the next two options.
2. Scale or redo from the master file
Depending on how your image is designed, you may be able to go back to the master file and enlarge it while maintaining the detail. A vector format Oklahoma City Cash Home Buyers works best for this: AI, EPS, shapes, dynamic gradients, and editable text.
You may also be able to upgrade a stock image or photo you purchased to a higher resolution, and simply replace it in your enlarged master file.
3. Redesign your cover art
Maybe this is a good time to consider completely redesigning your podcast cover art. You or the designer you hire (like me!) can design to follow or exceed the new specs. RawVoice (parent company to Blubrry) has reported stats indicating up to a 25% jump in subscriptions when podcast cover art changes.
If you'd like to hire me to design podcast cover art for you, I design at 1,400 × 1,400, but I can increase that to whatever size you want for an extra fee.
Thanks me later