Question

I have some issues with gzip (according to yslow) for css and js files.
I tried many different ways to implement the code in .htaccess but nothing works.

I cannot figure out what can be wrong – if I check in Firebug, there is no compression at all on this files. I tested also in some web sites (html files are compressed, but other not).

Do you have any suggestions?

Mainly I’m using .htaccess suggestions from https://github.com/h5bp/html5-boilerplate/blob/master/.htaccess

I’d appreaciate very much your help …

<IfModule mod_deflate.c>

  # Force deflate for mangled headers developer.yahoo.com/blogs/ydn/posts/2010/12/pushing-beyond-gzipping/
  <IfModule mod_setenvif.c>
    <IfModule mod_headers.c>
      SetEnvIfNoCase ^(Accept-EncodXng|X-cept-Encoding|X{15}|~{15}|-{15})$ ^((gzip|deflate)\s*,?\s*)+|[X~-]{4,13}$ HAVE_Accept-Encoding
      RequestHeader append Accept-Encoding "gzip,deflate" env=HAVE_Accept-Encoding
    </IfModule>
      BrowserMatch ^Mozilla/4 gzip-only-text/html
      BrowserMatch ^Mozilla/4\.0[678] no-gzip
      BrowserMatch \bMSIE !no-gzip !gzip-only-text/html
  </IfModule>

  # HTML, TXT, CSS, JavaScript, JSON, XML, HTC:
  <IfModule filter_module>
    FilterDeclare   COMPRESS
    FilterProvider  COMPRESS  DEFLATE resp=Content-Type $text/html
    FilterProvider  COMPRESS  DEFLATE resp=Content-Type $text/css
    FilterProvider  COMPRESS  DEFLATE resp=Content-Type $text/plain
    FilterProvider  COMPRESS  DEFLATE resp=Content-Type $text/xml
    FilterProvider  COMPRESS  DEFLATE resp=Content-Type $text/x-component
    FilterProvider  COMPRESS  DEFLATE resp=Content-Type $application/javascript
    FilterProvider  COMPRESS  DEFLATE resp=Content-Type $application/json
    FilterProvider  COMPRESS  DEFLATE resp=Content-Type $application/xml
    FilterProvider  COMPRESS  DEFLATE resp=Content-Type $application/xhtml+xml
    FilterProvider  COMPRESS  DEFLATE resp=Content-Type $application/rss+xml
    FilterProvider  COMPRESS  DEFLATE resp=Content-Type $application/atom+xml
    FilterProvider  COMPRESS  DEFLATE resp=Content-Type $application/vnd.ms-fontobject
    FilterProvider  COMPRESS  DEFLATE resp=Content-Type $image/svg+xml
    FilterProvider  COMPRESS  DEFLATE resp=Content-Type $image/x-icon
    FilterProvider  COMPRESS  DEFLATE resp=Content-Type $application/x-font-ttf
    FilterProvider  COMPRESS  DEFLATE resp=Content-Type $font/opentype
    FilterChain     COMPRESS
    FilterProtocol  COMPRESS  DEFLATE change=yes;byteranges=no
  </IfModule>

  <IfModule !mod_filter.c>
    # Legacy versions of Apache
    AddOutputFilterByType DEFLATE text/html text/plain text/css application/json
    AddOutputFilterByType DEFLATE application/javascript
    AddOutputFilterByType DEFLATE text/xml application/xml text/x-component
    AddOutputFilterByType DEFLATE application/xhtml+xml application/rss+xml application/atom+xml
    AddOutputFilterByType DEFLATE image/x-icon image/svg+xml application/vnd.ms-fontobject application/x-font-ttf font/opentype
  </IfModule>

</IfModule>

<ifModule mod_gzip.c>
mod_gzip_on Yes
mod_gzip_dechunk Yes
mod_gzip_item_include file \.(html?|txt|css|js|php)$
mod_gzip_item_include handler ^cgi-script$
mod_gzip_item_include mime ^text/.*
mod_gzip_item_include mime ^application/x-javascript.*
mod_gzip_item_exclude mime ^image/.*
mod_gzip_item_exclude rspheader ^Content-Encoding:.*gzip.*
</ifModule>


# ----------------------------------------------------------------------
# Expires headers (for better cache control)
# ----------------------------------------------------------------------

# These are pretty far-future expires headers.
# They assume you control versioning with filename-based cache busting
# Additionally, consider that outdated proxies may miscache
#   www.stevesouders.com/blog/2008/08/23/revving-filenames-dont-use-querystring/

# If you don't use filenames to version, lower the CSS  and JS to something like
#   "access plus 1 week" or so.

<IfModule mod_expires.c>
  ExpiresActive on

# Perhaps better to whitelist expires rules? Perhaps.
  ExpiresDefault                          "access plus 1 month"

# cache.appcache needs re-requests in FF 3.6 (thanks Remy ~Introducing HTML5)
  ExpiresByType text/cache-manifest       "access plus 0 seconds"

# Your document html
  ExpiresByType text/html                 "access plus 0 seconds"

# Data
  ExpiresByType text/xml                  "access plus 0 seconds"
  ExpiresByType application/xml           "access plus 0 seconds"
  ExpiresByType application/json          "access plus 0 seconds"

# Feed
  ExpiresByType application/rss+xml       "access plus 1 hour"
  ExpiresByType application/atom+xml      "access plus 1 hour"

# Favicon (cannot be renamed)
  ExpiresByType image/x-icon              "access plus 1 week"

# Media: images, video, audio
  ExpiresByType image/gif                 "access plus 1 month"
  ExpiresByType image/png                 "access plus 1 month"
  ExpiresByType image/jpg                 "access plus 1 month"
  ExpiresByType image/jpeg                "access plus 1 month"
  ExpiresByType video/ogg                 "access plus 1 month"
  ExpiresByType audio/ogg                 "access plus 1 month"
  ExpiresByType video/mp4                 "access plus 1 month"
  ExpiresByType video/webm                "access plus 1 month"

# HTC files  (css3pie)
  ExpiresByType text/x-component          "access plus 1 month"

# Webfonts
  ExpiresByType application/x-font-ttf    "access plus 1 month"
  ExpiresByType font/opentype             "access plus 1 month"
  ExpiresByType application/x-font-woff   "access plus 1 month"
  ExpiresByType image/svg+xml             "access plus 1 month"
  ExpiresByType application/vnd.ms-fontobject "access plus 1 month"

# CSS and JavaScript
  ExpiresByType text/css                  "access plus 1 year"
  ExpiresByType application/javascript    "access plus 1 year"
  ExpiresByType text/javascript         "access plus 1 year"
</IfModule>

# Enable Compresion
<FilesMatch ".(js|css|html|htm|php|xml)$">
SetOutputFilter DEFLATE
</FilesMatch>

# ----------------------------------------------------------------------
# ETag removal
# ----------------------------------------------------------------------

# FileETag None is not enough for every server.
<IfModule mod_headers.c>
  Header unset ETag
</IfModule>

# Since we're sending far-future expires, we don't need ETags for
# static content.
#   developer.yahoo.com/performance/rules.html#etags
FileETag None

Answer 1

Check with your host if they do have mod_deflate or mod_gzip enabled by default on their servers. Even though your Apache .htacess is correct it still need the modules to be enabled. Some shared hosts turn it off by default in order to save some CPU thus share resources with more clients which is bad for Web Performance Optimization.