Annotating the internet,

Our mission is to enable conversations over the world’s knowledge.

Building universal collaboration through social annotation.

The internet has transformed how we find and share information – but collaboration is not as productive as it could be. At Hypothesis, we aim to bring content and conversation together with a layer of social annotation that works across the entire web.

several staff members sitting outside, around a table


Company History.

Hypothesis was founded in 2011 by Dan Whaley. While working in the climate change field, Dan became increasingly frustrated by how distorted information circulated online. His exploration for a solution to enhance accuracy and elevate discourse led him to web annotation. 

Over a decade later, Hypothesis is pioneering the adoption of social annotation for education, research, business, and personal collaboration.

65 M.
1+ M.
Global Users
Team Members

icon of a globe and a pencil

An open platform for the global community. 

Web annotation is not a new concept. What distinguishes Hypothesis is our mission-driven philosophy and commitment to an open-source framework and interoperable standards. 

From 2014 to 2017, we led the W3C Web Annotation Working Group, helping to develop the vocabulary, data model, protocol, and recommendation that resulted in the standard for web annotation. 

We are also founding members of Invest In Open Infrastructure (IOI), an initiative dedicated to improving funding and resourcing for open technologies and systems supporting research and scholarship.

anno. logo

icon of a cylinder

Sustained by social enterprise.

Hypothesis is supported by Anno, a public benefit corporation that makes providing annotation and collaboration software possible. Anno is funded by an investment from venture capital and foundations like ITHAKA, the nonprofit provider of JSTOR, a digital library.

Anno was inspired by the work of Hypothesis Project, a non-profit organization that focuses on advocacy, standards, and the development of the larger paradigm of open annotation.

Our Values

icon of a text bubble


Always focused on the impact.


icon of 3 torsos


Built around the people who rely on us.

icon of a globe with a pencil

Universally accessible

Useful for anyone, anywhere, on any type of content.

icon of two hands

Neutral and unbiased

We favor no ideological or political positions.

icon of a pencil

Foster community

Moderated bottom-up, allowing for credibility without public identity.

icon of a circle with a corner folded up


We’re open about systems and governance.

icon of an infinity symbol

Long-term thinking

Creating infrastructure for 100 years, and beyond.

icon of a trophy

Work with the best

Remain humble.

icon of a crown


Helping each individual do their best work.

icon of a chart

Continuous improvement

Always thinking bigger and moving forward.

Make your mark

If our mission and values sound appealing, we’re always looking to add to our team. Learn more about careers at Hypothesis.

Careers at Hypothesis