Tumblr (stylized on its home page as tumblr.) is a microblogging and social networking website founded by David Karp in 2007, and owned by Yahoo! after 2013. The service allows users to post multimedia and additional content to a short-form blog. Users can follow additional users' blogs. Bloggers can additionally make their blogs private. For bloggers, a large number of of the website's features are accessed from a "dashboard" interface.

As of November 1, 2016, Tumblr hosts over 320.5 million blogs. As of January 2016, the website had 555 million monthly visitors.


Development of Tumblr began in 2006 throughout a two-week gap between contracts at David Karp's software consulting company, Davidville (housed at Karp's former internship with producer/incubator Fred Seibert's Frederator Studios which was located a block from Tumblr's current headquarters). Karp had been interested in tumblelogs (short-form blogs) for a few time and was waiting for one of the established blogging platforms to introduce their own tumblelogging platform. As no one had done so after a year of waiting, Karp and developer Marco Arment began working on their own tumblelogging platform. Tumblr was launched in February 2007 and within two weeks, the service had gained 75,000 users. Arment left the company in September 2010 to focus on Instapaper.

In early June 2012, Tumblr featured its first major brand advertising campaign in conjunction with Adidas. Adidas launched an official soccer Tumblr blog and bought placements on the user dashboard. This launch was only two months after Tumblr announced it would be moving towards paid advertising on its site.

On May 20, 2013, it was announced that Yahoo! and Tumblr had reached an agreement for Yahoo! to acquire Tumblr for $1.1 billion in cash. Many of Tumblr's users were unhappy with the news, causing a few to start a petition, achieving nearly 170,000 signatures. David Karp remained CEO and the deal was finalised on June 20, 2013.


Blog management

  • Dashboard: The dashboard is the primary tool for the typical Tumblr user. It is a live feed of recent posts from blogs that they follow. Through the dashboard, users are able to comment, reblog, and like posts from additional blogs that appear on their dashboard. The dashboard allows the user to upload text posts, images, video, quotes, or links to their blog with a click of a button displayed at the top of the dashboard. Users are additionally able to connect their blogs to their Twitter and Facebook accounts, so whenever they make a post, it will additionally be sent as a tweet and a status update.
  • Queue: Users are able to set up a schedule to delay posts that they make. They can spread their posts over several hours or even days.
  • Tags: For each post a user creates, they're able to help their audience find posts about certain topics by adding tags. If someone were to upload a picture to their blog and wanted their viewers to find pictures, they would add the tag #picture, and their viewers could use that word to search up posts with the tag #picture.
  • HTML editing: Tumblr allows users to edit their blog's theme HTML coding to control the appearance of their blog. Users are additionally able to use a custom domain name for their blog.


With Tumblr's 2009 acquisition of Tumblerette, an iOS application created by Jeff Rock and Garrett Ross, the service launched its official iPhone app. The site became available to BlackBerry smartphones on April 17, 2010 via a Mobelux application in BlackBerry World. In June 2012, Tumblr released a new version of its iOS app, Tumblr 3.0 allowing support for Spotify, hi-res images and offline access. An app for Android is additionally available. A Windows Phone app was released on April 23, 2013. An app for Google Glass was released on May 16, 2013.

Inbox and messaging

Tumblr blogs might optionally allow users to submit questions, either as themselves or anonymously, to the blog for a response. Tumblr additionally offered a "fan mail" function, allowing users to send messages to blogs that they follow.

On November 10, 2015, Tumblr introduced an integrated instant messaging function, allowing users to chat between additional Tumblr users. The feature is being rolled out in a "viral" manner; it was initially made available to a group of 1500 users; additional users might receive access to the messaging system if they're sent a message by any user that has received access to the system itself. The messaging system only supports text-based conversations, although additional features (such as group chat and image embeds) will be added in the future. The messaging platform will additionally replace the fan mail system, which has been deprecated.

Editorial content

In May 2012, Tumblr launched Storyboard, a blog managed by an in-house editorial team which features storeys and videos about noteworthy blogs and users on Tumblr. In April 2013, Storyboard was shut down.


  • As of November 1, 2016, Tumblr hosts over 320.5 million blogs and more than 141.4 billion posts in total.
  • In April 2013, the website received more than 13 billion global page views.
  • As of November 1, 2016, over 39 million posts were created on the site each day.

An analysis by AddThis of shares through their service in 2011 noted that Tumblr sharing had increased by 1299.5%.

The service is most popular with the teen and college-aged user segments with half of Tumblr's visitor base being under the age of 25.

Adult content

Tumblr is noted by technology journalists as having a sizable amount of pornographic content. The New York Times notes "pornography represents a fraction of content on the site, but not a trivial amount for a site with 100 million blogs." Karp revealed in June 2012 that between 2 and 4 percent of Tumblr's traffic is porn-related. Notwithstanding an analysis conducted by news and technology site TechCrunch has shown that over twenty-two percent of all traffic in and out of Tumblr is classified as pornography. In addition, a reported 16.45% of blogs on Tumblr exclusively contain porn. Tumblr's Community Guidelines permits adult-oriented content but requires that blogs that contain occasional or substantial adult content to be flagged as such. Sexually explicit videos aren't allowed to be uploaded to the website, but videos hosted elsewhere might be embedded. Some porn bloggers earn money by referring traffic to adult businesses through referrals and widgets.

As of July 20, 2013, policy updates enacted by Tumblr mean that pages classified as "NSFW" (not safe for work) won't feature in tag pages for users who aren't logged in or who have the "Safe Mode" activated. For users who're logged in to Tumblr, but don't have "Safe Mode" turned on, NSFW blogs should show up on search and tag pages; NSFW pages are indexed by search engines. In a public statement, the company conveyed the following:

Tumblr's longstanding policy regarding NSFW content hasn't changed and emphasises the importance of free expression. As addressed in these policies, we're constantly taking measures to ensure our users can avoid this content unless they'd like to see it. Anyone can opt-in by disabling Safe Mode in their Dashboard Settings.

In February 2016, the Indonesian government temporarily blocked access to Tumblr within the country because the site hosts pages that carried porn. The government shortly reversed its decision to block the site and said it had asked Tumblr to self-censor its pornographic content.

Self-harm and suicide

In February 2012, Tumblr's staff blog announced that the content policy would change to ban blogs that promote or advocate suicide, self-harm and eating disorders (pro-ana).

The suicide of a British teenager, Tallulah Wilson, raised the issue of suicide and self-harm promotion on Tumblr as Wilson was reported to have maintained a self-harm blog on the site. A user on the site is reported to have sent Wilson an image of a noose accompanied by the message: "here is your new necklace, try it on." In response to the Wilson case, Maria Miller, the UK's minister for culture, media and sport, said that social media sites like Tumblr need to remove "toxic" self-harm content.

Searching terms like "depression", "anxiety", and "suicide" on Tumblr now brings up a PSA page directing the user to resources like the national suicide lifeline, and 7 Cups of Tea; as well as an option to continue to the search results.

Corporate affairs

Tumblr's headquarters is on East twenty-first Street in New York City. The offices are on the tenth floor.

Tumblr's headquarters is at 35 East twenty-first Street in the Flatiron District in New York City's Silicon Alley. The company additionally maintains a support office in Richmond, Virginia. As of November 1, 2016, Tumblr has 393 employees. The company's logo is set in Bookman Old Style with a few modifications.


To date, Tumblr has received about $125 million of funding from investors. The company has raised funding from Union Square Ventures, Spark Capital, Martín Varsavsky, John Borthwick (Betaworks), Fred Seibert, Krum Capital, and Sequoia Capital (among additional investors).

In its first round of funding in October 2007, Tumblr raised $750,000 from Spark Capital and Union Square Ventures. In December 2008, the company raised $4.5 million in Series B funding and a further $5 million in April 2010. In December 2010, Tumblr raised $30 million in Series D funding. The company had a $800 million valuation in August 2011. In September 2011, the company raised $85 million in a round of funding led by Greylock Partners and Insight Venture Partners.

Revenue sources

In an interview with Nicole Lapin of Bloomberg West on September 7, 2012, David Karp said the site was monetized by advertising. Their first advertising launch started in May 2012 after 16 experimental campaigns. Tumblr made $13 million in revenue in 2012 and hopes to make $100 million in 2013. Tumblr reportedly spent $25 million to fund operations in 2012.

In 2013, Tumblr began allowing companies to pay to promote their own posts to a larger audience. Tumblr Head of Sales, Lee Brown, has quoted the average ad purchase on Tumblr to be nearly six figures. Tumblr additionally generates revenue by selling themes to users to change the appearance of their blog.

In July 2016, ads were implemented by default across all blogs. Users might opt out, and the service stated that a revenue sharing programme would be implemented at a later date.


Tumblr has received criticism for copyright violations by participating bloggers; however, Tumblr accepts Digital Millennium Copyright Act (DMCA) take-down notices. Tumblr's visual appeal has made it ideal for photoblogs that often include copyrighted works from others that are re-published without payment. Tumblr users can post unoriginal content by "Reblogging", a feature on Tumblr that allows users to re-post content taken from another blog onto their own blog.


Tumblr has been forced to manage spam and security problems. For example, a chain letter scam in May 2011 affected 130,000 users.

On December 3, 2012, Tumblr was attacked by a cross-site scripting worm deployed by the Internet troll group Gay Nigger Association of America. The message urged users to harm themselves and criticised blogging in general.

User interface changes

In 2015, Tumblr faced criticism by users for changes to its reblog mechanisms. In July 2015, the system was modified so that users can't remove or edit individual comments by additional users when reblogging a post; existing comments can only be removed all at once. Tumblr staff argued that the change was intended to combat "misattribution". In September 2015, Tumblr changed how threads of comments on reblogged posts are displayed; rather than a nested view with indentations for each post, all reblogs are now shown in a flat view, and user avatars were additionally added. The change was intended to improve the legibility of reblogs, especially on mobile platforms, and complements the inability to edit existing comments. Although a few users had requested such a change to combat posts made illegible by extremely large numbers of comments on a reblogged post, the majority of users (even those who's requested such a change) criticised the new format. The Verge was additionally critical of the changes, noting that it was cleaner, but made the site lose its "nostalgic charm". As of 2016, numerous Browser extensions have been created to try and combat or circumvent these changes.