Why is my Drupal site slow?

Common Causes of Drupal Performance Issues

When we at HostingDuty audit Drupal sites for slowness, we typically find three primary culprits: caching misconfigurations, resource-heavy modules, and database inefficiencies. These issues compound under load, causing page load times to spike significantly.

Caching Configuration

Drupal's built-in caching system is often the first area we examine. If cache pages are not enabled, every request triggers a full PHP execution and database query. We recommend enabling cache pages for anonymous users immediately. For authenticated users, configure cache contexts properly to ensure personalized content still renders quickly.

You can review cache settings in the Drupal admin interface at Configuration > Performance. If you're using a reverse proxy like Varnish, ensure your Drupal cache headers align with your proxy configuration. See our tutorial on Drupal caching best practices for detailed configuration steps.

Module Bloat

Every enabled module adds PHP code execution time and database overhead. We often find sites running 50+ modules when 10-15 would suffice. Each unnecessary module increases memory usage and slows down hook implementations.

Audit your module list by disabling unused modules and testing performance after each change. Use the Devel module to identify slow hooks and database queries. Our module optimization guide provides a systematic approach to this process.

Database Bottlenecks

Drupal relies heavily on database queries for content rendering. Unindexed tables, large node counts, and inefficient queries can cause severe slowdowns. We recommend running database optimization queries regularly and ensuring proper indexing on frequently queried fields.

For sites with high traffic, consider using a dedicated database server or managed database service. Check our database optimization checklist for specific queries and indexing strategies.

External Factors

Beyond Drupal configuration, external factors like slow hosting, missing CDN integration, and unoptimized assets contribute to perceived slowness. At HostingDuty, we recommend using a global CDN to serve static assets and reduce origin server load. Our CDN integration guide covers implementation details for major CDN providers.

Diagnostic Tools

Use Drupal's built-in performance monitoring tools and external services like Google PageSpeed Insights to identify specific bottlenecks. The Devel module provides detailed query logs and execution times for deeper analysis.

For comprehensive performance auditing, consult our Drupal performance diagnostic framework which outlines systematic testing procedures.