Improve the Speed of Your Magento Site

Caching is useful for files on a web server that very rarely change. Images, pdf files and other content can be cached, reducing the network traffic between the server, the client, and the HTTP proxies in between them.

Change in your .htaccess file and it will improve your site speed.

Note: first backup your htaccess file.

1.)

############################################
## enable apache served files compression
## http://developer.yahoo.com/performance/rules.html#gzip
    # Insert filter on all content
    SetOutputFilter DEFLATE
    # Insert filter on selected content types only
    #AddOutputFilterByType DEFLATE text/html text/plain text/xml text/css text/javascript
    # Netscape 4.x has some problems...
    BrowserMatch ^Mozilla/4 gzip-only-text/html
    # Netscape 4.06-4.08 have some more problems
    BrowserMatch ^Mozilla/4\.0[678] no-gzip
    # MSIE masquerades as Netscape, but it is fine
    BrowserMatch \bMSIE !no-gzip !gzip-only-text/html
    # Don't compress images
    SetEnvIfNoCase Request_URI \.(?:gif|jpe?g|png)$ no-gzip dont-vary
    # Make sure proxies don't deliver the wrong content
    Header append Vary User-Agent env=!dont-vary

2.)

############################################
## Add default Expires header
## http://developer.yahoo.com/performance/rules.html#expires
       ExpiresActive on
       ExpiresDefault "access plus 1 year"
    #ExpiresDefault "access plus 1 year"

3.)

Header unset Pragma
FileETag None
Header unset ETag
# cache images/pdf docs for 10 days

Header set Cache-Control "max-age=864000, public, must-revalidate"
Header unset Last-Modified

# cache html/htm/xml/txt diles for 2 days
Header set Cache-Control "max-age=7200, must-revalidate"  

4.)

Enable all catch from your site backend form System->Catch manegement