# How to set up canonical URL service for Themes

Source: https://dev.arcxp.com/themes/how-to-guides/how-to-setup-canonical-url-service-for-themes/

This page lists the configurations you must set up in the Canonical URL Service for each Themes website. This ensures that your content matches the [resolver](https://dev.arcxp.com/themes/how-to-guides/how-to-setup-canonical-url-service-for-themes/) configured for your Themes website in PageBuilder.

> **Note:**
> 
> You have some flexibility to customize URL configuration patterns in [URL Service](https://docs.arcxp.com/en/products/arc-xp-administration/canonical-urls/configuring-url-formats.html), but you must also customize your [resolvers](https://dev.arcxp.com/themes/how-to-guides/how-to-setup-canonical-url-service-for-themes/) to match those patterns.

To ensure SEO best practices, all canonical URLs you configure must have the trailing slash. This prevents an unnecessary CDN redirect to the URL with the trailing slash on the page load. Examples:

| PAGE TYPE | CRITERIA           | FORMAT                                                                                                      |
| --------- | ------------------ | ----------------------------------------------------------------------------------------------------------- |
| video     | {"type":"video"}   | /video/%publish\_date\|year()%/%publish\_date|month()%/%publish\_date|day()%/%headlines.basic|slugify()%/   |
| gallery   | {"type":"gallery"} | /gallery/%publish\_date\|year()%/%publish\_date|month()%/%publish\_date|day()%/%headlines.basic|slugify()%/ |
| author    | {"type":"author"}  | /author/%slug\|slugify()%/                                                                                  |

Additionally, set the **Default Format** to the following, which applies to articles:

Terminal window

```bash
%websites.{website_id}.website_section.path%/%publish_date|year()%/%publish_date|month()%/%publish_date|day()%/%headlines.basic|slugify()%/
```

> **Important:**
> 
> Replace `<website_id>` with the website ID of the site you are configuring. Each site must have its own configuration and default format.