Official prerender.io .htaccess for Apache.

.htaccess

# Change YOUR_TOKEN to your prerender token and uncomment that line if you want to cache urls and view crawl stats
# Change http://example.com (at the end of the last RewriteRule) to your website url

<IfModule mod_headers.c>
    #RequestHeader set X-Prerender-Token "YOUR_TOKEN"
</IfModule>

<IfModule mod_rewrite.c>
    RewriteEngine On

    <IfModule mod_proxy_http.c>
        RewriteCond %{HTTP_USER_AGENT} baiduspider|facebookexternalhit|twitterbot|rogerbot|linkedinbot|embedly|quora\ link\ preview|showyoubot|outbrain|pinterest|slackbot|vkShare|W3C_Validator [NC,OR]
        RewriteCond %{QUERY_STRING} _escaped_fragment_[NC,OR]
        RewriteCond %{HTTP:x-bufferbot} !^$
        
        # Only proxy the request to Prerender if it's a request for HTML
        RewriteRule ^(?!.*?(\.js|\.css|\.xml|\.less|\.png|\.jpg|\.jpeg|\.gif|\.pdf|\.doc|\.txt|\.ico|\.rss|\.zip|\.mp3|\.rar|\.exe|\.wmv|\.doc|\.avi|\.ppt|\.mpg|\.mpeg|\.tif|\.wav|\.mov|\.psd|\.ai|\.xls|\.mp4|\.m4a|\.swf|\.dat|\.dmg|\.iso|\.flv|\.m4v|\.torrent|\.ttf|\.woff))(.*) http://service.prerender.io/http://example.com/$2 [P,L]
    </IfModule>
</IfModule>

the condition

RewriteCond %{HTTP:x-bufferbot} !^$

is useful to allow buffer.com scraper bot to use the prerendered version of the page