Not a huge fan of share buttons in general, but people seem to like them. Below is a list of social networks and their respective, good ol' fashion, URLs for sharing content.
[TITLE]
indicates where to add your own title, url, description etc. Do not include the square brackets.
Feel free to add / update them, either in the comments or a fork.
Reference:
https://developers.facebook.com/docs/reference/plugins/share-links/
URL (Auto generates data based on meta
tags):
https://www.facebook.com/sharer/sharer.php?u=[URL]
Alternative URL (User created data):
http://www.facebook.com/sharer/sharer.php?s=100&p[title]=[TITLE]&p[url]=[URL]&p[images][0]=[IMAGE]&[summary]=[DESCRIPTION]
Reference:
https://dev.twitter.com/docs/intents
URL:
https://twitter.com/intent/tweet?text=[TITLE]&url=[URL]
Reference:
https://developers.google.com/+/web/share/#sharelink
URL:
https://plus.google.com/share?url=[URL]
Reference:
N/A
URL:
http://pinterest.com/pin/create/button/?url=[URL]&description=[DESCRIPTION]&media=[IMAGE]
Reference:
N/A
URL:
http://reddit.com/submit?url=[URL]&title=[TITLE]
Reference:
N/A
URL:
http://digg.com/submit?url=[URL]&title=[TITLE]
Reference:
N/A
URL:
http://del.icio.us/post?url=[URL]&title=[TITLE]
Reference:
N/A
URL:
http://www.stumbleupon.com/submit?url=[URL]&title=[TITLE]
Reference:
https://developer.linkedin.com/documents/share-linkedin
URL:
http://www.linkedin.com/shareArticle?mini=true&url=[URL]&title=[TITLE]
Reference:
http://open.weibo.com/sharebutton
URL:
http://service.weibo.com/share/share.php?title=[TITLE]&url=[URL]&[pic]=[IMAGE]
Reference:
[Cannot find anything official]
https://stackoverflow.com/questions/21935149/sharing-link-on-whatsapp-from-mobile-website-not-application-for-android
URL:
whatsapp://send?text=[SOME OPTIONAL TEXT][ ][URL]
Reference:
https://media.line.me/en/#lineitbutton
URL:
https://lineit.line.me/share/ui?url=[URL]
Reference:
http://developer.mixi.co.jp/en/connect/mixi_plugin/mixi_check/spec_mixi_check/
URL:
https://mixi.jp/share.pl?u=[URL]
Reference:
https://developer.mozilla.org/en-US/docs/Learn/HTML/Introduction_to_HTML/Creating_hyperlinks
URL:
mailto:[EMAIL]?subject=[SUBJECT]&body=[BODY]
Reference:
https://developer.mozilla.org/en-US/docs/Web/API/Window/print
URL:
javascript:window.print()