Text over image isn't clear when viewed on mobile

Question

I want to make an image which has text displayed over a an image. The size that I designed the image at is 360*600. When I use Photoshop and export as .JPG with 90% quality it tends to look blurry on mobile screen. However the other example image that I have shown looks crisp and clear when seen on a mobile phone. Can you please explain why this happens?

I am new to design and still learning, so I may not know all the terms and solutions that you suggest immediately.

What I ended up making:

The quality I want to make:

Answer 1

A few issues...

Image size

Your image is 360 × 600 pixels. The example image is 1000 × 1262 pixels. That is a fairly big difference in size. I'm not sure what mobile you're viewing your image on but most new smart phones have high pixel density screens—so what you think is a 360 × 600 pixel screen may actually be 720 × 1200 pixels or more.

Just so you can see the comparison, here are both images side by side at they're actual size:

So first thing; increase your image size.

Type size

Your type size is significantly smaller than the example. Compare your type size with the example and you can see you have probably double the number of words in a similar amount of space:

When you're working for print you can get away with 7 or 8 point type, but with the limited pixels of screens you want your type a fair amount larger than that; increase your type size.

Choice of Typeface

At small sizes especially, your choice of typeface makes a big impact on readability; in this case the difference in x-height is very noticeable.

Compare your text, which has a very low x-height (roughly 1/2 the ascender height)...

...against the example, which has a larger x-height (at least 2/3 the ascender height) with large bowls and counters—things that improve readability at small sizes:

A better typeface may be an option; if not—be aware of things like a small x-height and compensate by increasing the size accordingly.

TL;DR

Make everything bigger.

Answer 2

It's very likely that the mobile screen you are previewing the image on is a high-resolution retina display. On these screens, the pixel density is going to be at least 330 PPI (pixels per inch) compared to your typical computer screen that comes in at 72 - 90 PPI. Your images are looking blurry because they're designed at 1x resolution. If you want them to be crisp on a mobile screen, try making them at 2x, or in this instance 720 x 1200px. This should sharpen things up considerably even if your saving the JPG at 90%. Hope this helps!

For more information on Retina displays, see this article here.

Answer 3

save it in PNG. Jpeg is loose and mostly used for reference only. Even at low resolution, PNG will look crisp on mobile.