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Settings under Performance

CSS Gzip will no longer be updated/supported and is considered obsolete. All future development is being done in the Advanced CSS/JS Aggregation module.

Based off of Javascript Aggregator this module will gzip your aggregated css files. For Drupal 6.x


  • It's compatible with Apache 1.3 (works great with cheap hosting).
  • Compresses the content once and saves the result (less CPU load on server).
  • Uses level 9 compression because it's only run once per file (smaller file size).
  • In general, all you need to do is enable the module and it works (no core hacking/modifying .htaccess).


  • Requires Clean URL's in order to work (mod_rewrite).
  • Tested on Apache, other http servers not tested.
  • Requires download method to be public (check in admin/settings/file-system)

If your using private downloads, Gzipping of js & css can be achieved with the Boost module. I also recommend using the Parallel module as well for this use case (private downloads).

What about mod_deflate?

Long story short this is faster.

How do I know it's working?

The YSlow Firefox add-on has a tab called components; you can check for gzip compression there. See YSlow User Guide -> Components View.

Drupal 7?

This is part of core now!

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