Introduction

The tailwind starter blog has out of the box support for Next.js's built-in image component and automatically swaps out default image tags in markdown or mdx documents to use the Image component provided.

Usage

To use in a new page route / javascript file, simply import the image component and call it e.g.

import Image from 'next/image'

function Home() {
  return (
    <>
      <h1>My Homepage</h1>
      <Image src="/me.png" alt="Picture of the author" width={500} height={500} />
      <p>Welcome to my homepage!</p>
    </>
  )
}

export default Home

For a markdown file, the default image tag can be used and the default img tag gets replaced by the Image component in the build process.

Assuming we have a file called ocean.jpg in data/img/ocean.jpg, the following line of code would generate the optimized image.

![ocean](/static/images/ocean.jpg)

Alternatively, since we are using mdx, we can just use the image component directly! Note, that you would have to provide a fixed width and height. The img tag method parses the dimension automatically.

<Image alt="ocean" src="/static/images/ocean.jpg" width={256} height={128} />

Note: If you try to save the image, it is in webp format, if your browser supports it!

Photo by YUCAR FotoGrafik on Unsplash

Benefits

• Smaller image size with Webp (~30% smaller than jpeg)
• Responsive images - the correct image size is served based on the user's viewport
• Lazy loading - images load as they are scrolled to the viewport
• Avoids Cumulative Layout Shift
• Optimization on demand instead of build-time - no increase in build time!

Limitations

• Due to the reliance of next/image, unless you are using an external image CDN like Cloudinary or Imgix, it is practically required to use Vercel for hosting. This is because the component acts like a serverless function that calls a highly optimized image CDN.

  If you do not want to be tied to Vercel, you can remove imgToJsx in remarkPlugins in lib/mdx.js. This would avoid substituting the default img tag.

  Alternatively, one could wait for image optimization at build time to be supported. A different library, next-optimized-images does that, although it requires transforming the images through webpack which is not done here.

• Images from external links are not passed through next/image

• All images have to be stored in the public folder e.g /static/images/ocean.jpeg

Markdown and Mdx parsing is supported via unified, and other remark and rehype packages. next-mdx-remote allows us to parse .mdx and .md files in a more flexible manner without touching webpack.

Github flavored markdown is used. mdx-prism provides syntax highlighting capabilities for code blocks. Here's a demo of how everything looks.

The following markdown cheatsheet is adapted from: https://guides.github.com/features/mastering-markdown/

What is Markdown?

I love using Next.js

Markdown is a way to style text on the web. You control the display of the document; formatting words as bold or italic, adding images, and creating lists are just a few of the things we can do with Markdown. Mostly, Markdown is just regular text with a few non-alphabetic characters thrown in, like # or *.

Syntax guide

Here’s an overview of Markdown syntax that you can use anywhere on GitHub.com or in your own text files.

Headers

# This is a h1 tag

## This is a h2 tag

#### This is a h4 tag

This is a h1 tag

This is a h2 tag

This is a h4 tag

Emphasis

_This text will be italic_

**This text will be bold**

_You **can** combine them_

This text will be italic

This text will be bold

You can combine them

Lists

Unordered

- Item 1
- Item 2
  - Item 2a
  - Item 2b

• Item 1
• Item 2
  • Item 2a
  • Item 2b

Ordered

1. Item 1
1. Item 2
1. Item 3
   1. Item 3a
   1. Item 3b

1. Item 1
2. Item 2
3. Item 3
   1. Item 3a
   2. Item 3b

Images

![GitHub Logo](https://github.githubassets.com/images/modules/logos_page/GitHub-Mark.png)
Format: ![Alt Text](url)

Links

http://github.com - automatic!
[GitHub](http://github.com)

http://github.com - automatic! GitHub

Blockquotes

As Kanye West said:

> We're living the future so
> the present is our past.

As Kanye West said:

We're living the future so the present is our past.

Inline code

I think you should use an
`<addr>` element here instead.

I think you should use an <addr> element here instead.

Syntax highlighting

Here’s an example of how you can use syntax highlighting with GitHub Flavored Markdown:

```js:fancyAlert.js
function fancyAlert(arg) {
  if (arg) {
    $.facebox({ div: '#foo' })
  }
}

And here's how it looks - nicely colored with styled code titles!

function fancyAlert(arg) {
  if (arg) {
    $.facebox({ div: '#foo' })
  }
}

Task Lists

- [x] list syntax required (any unordered or ordered list supported)
- [x] this is a complete item
- [ ] this is an incomplete item

• list syntax required (any unordered or ordered list supported)
• this is a complete item
• this is an incomplete item

Tables

You can create tables by assembling a list of words and dividing them with hyphens - (for the first row), and then separating each column with a pipe |:

| First Header                | Second Header                |
| --------------------------- | ---------------------------- |
| Content from cell 1         | Content from cell 2          |
| Content in the first column | Content in the second column |

Strikethrough

Any word wrapped with two tildes (like ~~this~~) will appear crossed out.