Can Firefox display JP2 images?

JP2 images are not supported on Firefox.

But you can use the <picture> element to provide multiple image formats so the browser can choose and display the supported image format:

<picture>
    <source srcset="img/example.jp2" type="image/jp2"> <!-- format supported by safari -->
    <source srcset="img/example.webp" type="image/webp"> <!-- format supported on many browsers -->
    <source srcset="img/example.jpg" type="image/jpeg"> <!-- common supported format -->
    <img src="img/example.jpg" alt="example-alt-text"> <!-- default -->
</picture>

Note: An alternative to the JP2 format could be the WebP format:

• Comparison WebP, JPEG, JP2/JPEG2000
• More about the WebP format

(JP2) Supported browser below:

Firefox: Not supported.

Chrome: Not supported.

Safari: Supported.

You can also check this link: https://caniuse.com/#feat=jpeg2000