How to add SVG backgrounds into the Gutenberg editor

By Matt Visiwig Jan 5, 2022

Here is a quick demo of what we want to achieve:

This is an HTML block with a background.

All you need is to grab a background from SVGBackgrounds.com/free and to copy and paste code.

You can create the background style once and reuse it later on the page with ease.

Like so.

Creating a reusable class

First step is to create an HTML block and inside we need to add opening and closing style tags.

<style>
   /* YOUR CSS CODE WILL GO HERE */
</style>

Next we need to create a class, so we can reuse the background on different Gutenberg blocks. Within the <style> tags we call the class class-name, placing a . (period) at the start of the class name. A class name needs to start with a letter and can consist of letters, numbers, hyphens (-), and underscores (_). Finally, all the CSS rules will live between braces { }.

<style>
   .class-name{
      /* YOUR BACKGORUND HERE */
   }
</style>

Now we’ll visit SVGBackgrounds.com/free and grab CSS code from our chosen background. After you find and customize a background, click the EXPORT button and then the CSS button to add the CSS code right to your clipboard. You can see where to paste it within the class we created, in the above code example. Here is what I ended up with:

<style>
   .class-name{
      background-color: #ffaa00;
      background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='100%25' height='100%25' viewBox='0 0 1600 800'%3E%3Cg %3E%3Cpath fill='%23ffb100' d='M486 705.8c-109.3-21.8-223.4-32.2-335.3-19.4C99.5 692.1 49 703 0 719.8V800h843.8c-115.9-33.2-230.8-68.1-347.6-92.2C492.8 707.1 489.4 706.5 486 705.8z'/%3E%3Cpath fill='%23ffb800' d='M1600 0H0v719.8c49-16.8 99.5-27.8 150.7-33.5c111.9-12.7 226-2.4 335.3 19.4c3.4 0.7 6.8 1.4 10.2 2c116.8 24 231.7 59 347.6 92.2H1600V0z'/%3E%3Cpath fill='%23ffbe00' d='M478.4 581c3.2 0.8 6.4 1.7 9.5 2.5c196.2 52.5 388.7 133.5 593.5 176.6c174.2 36.6 349.5 29.2 518.6-10.2V0H0v574.9c52.3-17.6 106.5-27.7 161.1-30.9C268.4 537.4 375.7 554.2 478.4 581z'/%3E%3Cpath fill='%23ffc500' d='M0 0v429.4c55.6-18.4 113.5-27.3 171.4-27.7c102.8-0.8 203.2 22.7 299.3 54.5c3 1 5.9 2 8.9 3c183.6 62 365.7 146.1 562.4 192.1c186.7 43.7 376.3 34.4 557.9-12.6V0H0z'/%3E%3Cpath fill='%23ffcc00' d='M181.8 259.4c98.2 6 191.9 35.2 281.3 72.1c2.8 1.1 5.5 2.3 8.3 3.4c171 71.6 342.7 158.5 531.3 207.7c198.8 51.8 403.4 40.8 597.3-14.8V0H0v283.2C59 263.6 120.6 255.7 181.8 259.4z'/%3E%3Cpath fill='%23ffd914' d='M1600 0H0v136.3c62.3-20.9 127.7-27.5 192.2-19.2c93.6 12.1 180.5 47.7 263.3 89.6c2.6 1.3 5.1 2.6 7.7 3.9c158.4 81.1 319.7 170.9 500.3 223.2c210.5 61 430.8 49 636.6-16.6V0z'/%3E%3Cpath fill='%23ffe529' d='M454.9 86.3C600.7 177 751.6 269.3 924.1 325c208.6 67.4 431.3 60.8 637.9-5.3c12.8-4.1 25.4-8.4 38.1-12.9V0H288.1c56 21.3 108.7 50.6 159.7 82C450.2 83.4 452.5 84.9 454.9 86.3z'/%3E%3Cpath fill='%23ffef3d' d='M1600 0H498c118.1 85.8 243.5 164.5 386.8 216.2c191.8 69.2 400 74.7 595 21.1c40.8-11.2 81.1-25.2 120.3-41.7V0z'/%3E%3Cpath fill='%23fff852' d='M1397.5 154.8c47.2-10.6 93.6-25.3 138.6-43.8c21.7-8.9 43-18.8 63.9-29.5V0H643.4c62.9 41.7 129.7 78.2 202.1 107.4C1020.4 178.1 1214.2 196.1 1397.5 154.8z'/%3E%3Cpath fill='%23ffff66' d='M1315.3 72.4c75.3-12.6 148.9-37.1 216.8-72.4h-723C966.8 71 1144.7 101 1315.3 72.4z'/%3E%3C/g%3E%3C/svg%3E");
      background-attachment: fixed;
      background-size: cover;
      /* ADD EXTRA CSS HERE */
   }
</style>

The class is now created. If we associate this class with any block, we will see the background!

How to apply a background class to any Gutenberg block

Now we can apply this CSS class to nearly any Gutenberg block on this page.

When you select any block, options should appear in the in the block menu. The option we want is on the bottom and labeled Advanced. We’ll place our class name, without the . (period) into the “Additional CSS class(es)” field. Now the style should apply to the block. You may not see it in the editor, but you should see it on the published page or post.

This might not look perfect, therefore we may need to add additional CSS rules. I’ll give you extra CSS rules to add and you can experiment and adjust as needed.

Styling the Gutenberg block and background

It is likely that your default blocks do not expect a background and adding a background may not look great at first. This depends on your theme and installed Gutenberg blocks, of course.

Here are a few CSS rules to add to the class you created. Using a combination of these additional rules may help the newly styles block look much better.

<style>
   .class-name{
      background-color: #ffaa00;
      background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='100%25' height='100%25' viewBox='0 0 1600 800'%3E%3Cg %3E%3Cpath fill='%23ffb100' d='M486 705.8c-109.3-21.8-223.4-32.2-335.3-19.4C99.5 692.1 49 703 0 719.8V800h843.8c-115.9-33.2-230.8-68.1-347.6-92.2C492.8 707.1 489.4 706.5 486 705.8z'/%3E%3Cpath fill='%23ffb800' d='M1600 0H0v719.8c49-16.8 99.5-27.8 150.7-33.5c111.9-12.7 226-2.4 335.3 19.4c3.4 0.7 6.8 1.4 10.2 2c116.8 24 231.7 59 347.6 92.2H1600V0z'/%3E%3Cpath fill='%23ffbe00' d='M478.4 581c3.2 0.8 6.4 1.7 9.5 2.5c196.2 52.5 388.7 133.5 593.5 176.6c174.2 36.6 349.5 29.2 518.6-10.2V0H0v574.9c52.3-17.6 106.5-27.7 161.1-30.9C268.4 537.4 375.7 554.2 478.4 581z'/%3E%3Cpath fill='%23ffc500' d='M0 0v429.4c55.6-18.4 113.5-27.3 171.4-27.7c102.8-0.8 203.2 22.7 299.3 54.5c3 1 5.9 2 8.9 3c183.6 62 365.7 146.1 562.4 192.1c186.7 43.7 376.3 34.4 557.9-12.6V0H0z'/%3E%3Cpath fill='%23ffcc00' d='M181.8 259.4c98.2 6 191.9 35.2 281.3 72.1c2.8 1.1 5.5 2.3 8.3 3.4c171 71.6 342.7 158.5 531.3 207.7c198.8 51.8 403.4 40.8 597.3-14.8V0H0v283.2C59 263.6 120.6 255.7 181.8 259.4z'/%3E%3Cpath fill='%23ffd914' d='M1600 0H0v136.3c62.3-20.9 127.7-27.5 192.2-19.2c93.6 12.1 180.5 47.7 263.3 89.6c2.6 1.3 5.1 2.6 7.7 3.9c158.4 81.1 319.7 170.9 500.3 223.2c210.5 61 430.8 49 636.6-16.6V0z'/%3E%3Cpath fill='%23ffe529' d='M454.9 86.3C600.7 177 751.6 269.3 924.1 325c208.6 67.4 431.3 60.8 637.9-5.3c12.8-4.1 25.4-8.4 38.1-12.9V0H288.1c56 21.3 108.7 50.6 159.7 82C450.2 83.4 452.5 84.9 454.9 86.3z'/%3E%3Cpath fill='%23ffef3d' d='M1600 0H498c118.1 85.8 243.5 164.5 386.8 216.2c191.8 69.2 400 74.7 595 21.1c40.8-11.2 81.1-25.2 120.3-41.7V0z'/%3E%3Cpath fill='%23fff852' d='M1397.5 154.8c47.2-10.6 93.6-25.3 138.6-43.8c21.7-8.9 43-18.8 63.9-29.5V0H643.4c62.9 41.7 129.7 78.2 202.1 107.4C1020.4 178.1 1214.2 196.1 1397.5 154.8z'/%3E%3Cpath fill='%23ffff66' d='M1315.3 72.4c75.3-12.6 148.9-37.1 216.8-72.4h-723C966.8 71 1144.7 101 1315.3 72.4z'/%3E%3C/g%3E%3C/svg%3E");
      background-attachment: fixed;
      background-size: cover;

      /* EXTRA CSS RULES */
      padding: 30px; /* add space inside container */
      margin: 15px; /* add space outside container */
      color: white; /* change the text color */
      font-weight: bold; /* makes the text bold */
      text-shadow: 2px 2px 5px black; /* adds a shadow to the text */
      border: 5px solid blue; /* adds a blue border to the container */
   }
</style>

You can change the values to suit your needs. Change the text color to red or black. Increase the padding to 60px;

Note that some rules may not work if your theme styles have priority. You can try overriding your theme styles by adding !important at the end of a value, like so:

padding: 30px !important;

CSS can be tricky, but messing around with styles like this is how I learned. It takes time, but when you pick up a little here and there, you’ll eventually be able to build entire websites. Good luck.

How to add the class everywhere on your website

Lastly, this class can only be used on this page, but what if we wanted to be able to use this class on any page across your entire website?

Easy.

All we have to do is place the CSS code in a different spot of the WordPress backend. Simply visit Appearance > Customize (or type “/wp-admin/customize.php” after your domain name in the address bar). Next click Additional CSS and add all the code, minus the <style> and </style> tags. Don’t forget to save by clicking the Publish button. Now these CSS rules will load across your entire website, and you can use the class we created on any Gutenberg block, anywhere. Enjoy!