Contao, ExpressionEngine, and Backdrop CMS all support content-driven websites, but they suit different teams and use different CDN integration paths. Contao combines structured site management with built-in asset URL settings. ExpressionEngine emphasizes flexible content modeling and template control. Backdrop CMS offers a Drupal-derived system designed for organizations that want capable content management with a comparatively focused platform.
This guide helps you compare the three systems and understand how each one connects to CDNsun. It covers the architecture and the settings involved without repeating the full configuration procedures. When you are ready to implement the integration, continue with the dedicated tutorial for your CMS.
For more platforms, see our companion guides to WordPress, Joomla, Drupal, and Magento CDN integration and PrestaShop, Odoo, TYPO3, and Grav CDN integration.
Why use a CDN with a CMS?
A content management system creates pages, manages media, applies templates, and controls publishing workflows. A content delivery network handles a different part of the stack: it caches suitable files and serves them from distributed infrastructure. Visitors can then retrieve static assets from a CDN location instead of requesting every copy from the origin server.
For a typical CMS website, a CDN can help:
- reduce latency for visitors located far from the origin;
- offload requests for images, CSS, JavaScript, fonts, and downloads;
- leave more origin capacity for uncached pages and application processing;
- improve delivery consistency for geographically distributed traffic; and
- absorb sudden increases in static-asset requests more efficiently.
A CDN complements CMS and server optimization rather than replacing them. Database performance, application caching, efficient templates, optimized images, and correct HTTP caching rules still matter. The practical integration task is to make eligible asset URLs use the CDN hostname while keeping administrative, personalized, and other dynamic routes on the origin.
Contao, ExpressionEngine, or Backdrop CMS: a quick comparison
| CMS | Good fit for | Why teams choose it | CDN integration path | Tutorial-tested environment |
|---|---|---|---|---|
| Contao | Structured company sites, portals, multilingual sites, and custom web projects | Integrated page, content, file, and access management with a developer-friendly framework | Native Files URL and Assets URL settings | Contao Open Source CMS 5.3.51 |
| ExpressionEngine | Custom publishing, editorial sites, membership projects, and content with tailored fields | Flexible channels, fields, templates, and front-end control | Native theme and upload-directory URL settings | ExpressionEngine 7.5.26 |
| Backdrop CMS | Small and medium-sized organizational sites, community sites, and Drupal 7-oriented projects | Familiar modular content architecture with an emphasis on a manageable operating footprint | Contributed CDN module in Origin Pull mode | Backdrop CMS 1.34.3 with CDN module 1.x-2.10.0 |
The versions in this table record the environments used to test the tutorials. They do not indicate the newest releases or define compatibility for every installation.
Contao CDN integration overview
Contao Open Source CMS is a structured PHP content management system for websites that need more than a basic page editor. It brings page trees, reusable content elements, file management, forms, permissions, multilingual content, and extension support into one administration environment. It can suit company websites, institutional portals, campaign sites, and custom applications built by teams that value an orderly backend and framework-level extensibility.
For CDN delivery, Contao has a particularly direct path: the relevant configuration is native to the CMS. The Files URL controls the base URL used for managed files, while the Assets URL covers application assets. Pointing these settings to the prepared CDN hostname allows Contao to generate CDN-based URLs without an additional extension.
The tutorial was tested with Contao Open Source CMS 5.3.51. Treat that value as the tested environment. Before applying the same configuration elsewhere, compare your installation and theme behavior, then verify which file and asset requests are rewritten.
Follow the complete Contao CDN integration tutorial for the exact configuration sequence.
ExpressionEngine CDN integration overview
ExpressionEngine is a flexible CMS built around channels, custom fields, templates, and member capabilities. Rather than imposing a fixed presentation model, it gives developers and content teams control over how structured entries are stored and rendered. That makes it suitable for editorial websites, publications, member-driven projects, directories, and custom content applications where the data model and front end need to follow project-specific requirements.
Its CDN integration also uses built-in settings. Theme resources can be routed through the CDN by changing the Themes directory URL. Files managed through upload directories use a separate Upload directory URL setting for each directory. This distinction matters: a site with several upload destinations may need each one reviewed so that all intended media paths use the CDN hostname.
No additional add-on is required for the method covered here. The tutorial was tested with ExpressionEngine 7.5.26, which should be read as a record of the verified tutorial environment rather than a statement about the newest release.
Follow the complete ExpressionEngine CDN integration tutorial to configure the theme and upload-directory URLs correctly.
Backdrop CMS CDN integration overview
Backdrop CMS is an open-source content management system with roots in Drupal 7. It retains concepts such as content types, fields, views, layouts, roles, permissions, and contributed modules while focusing on the needs of small and medium-sized organizations. It is a practical option for company, nonprofit, community, education, and information-rich sites whose teams want a familiar modular architecture without moving to a substantially different content model.
Unlike Contao and ExpressionEngine, the covered Backdrop integration requires the contributed CDN module. The module is configured in Origin Pull mode, so the CDN retrieves eligible files from the existing origin as they are requested. The setup uses an HTTPS CDN mapping to associate asset requests with the secure CDN hostname. CSS aggregation is also enabled in the tested configuration.
The tutorial was verified with Backdrop CMS 1.34.3 and CDN module 1.x-2.10.0. Module and core versions should be checked together before implementation because this path depends on an extension rather than native URL fields alone.
Follow the complete Backdrop CMS CDN integration tutorial for module installation, Origin Pull configuration, HTTPS mapping, and verification.
Verification basics for all three CMS platforms
Changing a URL field or module setting is only the start of a reliable rollout. After configuration, inspect the generated requests and confirm that the CDN is serving the intended content.
- Test several public page types. Check the homepage, content pages, listing pages, forms, and any page using a different template or layout.
- Inspect requests in browser developer tools. Confirm that intended images, stylesheets, scripts, fonts, and downloads use the CDN hostname.
- Check HTTPS delivery. Look for certificate errors, mixed-content warnings, blocked resources, and accidental HTTP asset URLs.
- Confirm origin access. Open an affected asset through both its origin URL and CDN URL. Matching paths help distinguish an origin problem from a CMS URL-generation problem.
- Clear relevant caches. Purge CMS, application, browser, and CDN caches when older URLs remain visible after a change.
- Keep dynamic routes on the correct host. Administration pages, sessions, forms, personalized responses, and other application traffic should not move to a static CDN mapping unintentionally.
Common problems include an incorrect hostname, missing HTTPS coverage, stale rendered output, a theme that constructs URLs independently, or an upload directory that was not included. On Backdrop CMS, also verify the module mapping and CSS aggregation behavior. On ExpressionEngine, review every upload directory rather than assuming one URL change covers them all.
Which CMS should you choose?
Choose the CMS according to your content structure, team workflow, maintenance capacity, and development model. CDN compatibility should confirm the decision, not drive it by itself.
- Choose Contao when you want structured page and content management, a capable built-in administration system, and native CDN URL controls for files and assets.
- Choose ExpressionEngine when custom fields, channels, templates, and precise front-end control are central to the project. Its separate settings for themes and upload directories work well when teams understand their media structure.
- Choose Backdrop CMS when a Drupal 7-style content architecture, contributed modules, and a focused operating model fit the organization. Its CDN path adds a module, but the Origin Pull approach remains straightforward once the mapping is in place.
All three can deliver static assets through a CDN. Contao offers the simplest native split between files and assets. ExpressionEngine provides native control across themes and individual upload directories. Backdrop CMS uses a contributed module and therefore requires an additional compatibility and configuration check.
Start your CMS CDN setup
Prepare your origin, CDN hostname, and HTTPS delivery before changing the CMS. Then follow the platform-specific tutorial and verify the resulting asset requests across representative pages.
- Set up CDN delivery for Contao
- Set up CDN delivery for ExpressionEngine
- Set up CDN delivery for Backdrop CMS
Our service uses pay-as-you-go pricing with no monthly fee and includes free SSL and 24/7 support. You can test the integration with a 15-day free trial when you sign up for CDNsun.