Flattr was a Swedish-based microdonation subscription service, where subscribers opted in to pay a monthly patronage to help fund their favourite websites and creators.

"[5] The final version allowed users to pay a monthly donation (provided a minimum of 3 dollars) which was automatically split among websites, pages or platforms that are "flattrd" by Flattr's web extension.

[citation needed] In December 2010, Flattr received large-scale attention when it was tweeted to be a method of donating money to WikiLeaks, which had recently been cut off by PayPal, Visa, and MasterCard.

On 24 May 2018, Flattr made changes to their privacy policy to comply with the GDPR and began deleting previously collected user activity after three months.

[15] Flattr 2.0 was able to be used on websites via a meta tag, and supported various creator platforms including YouTube, Wordpress, Vimeo, Twitter, Twitch, SoundCloud, GitHub, 500px and Flickr.