Yahoo websites worldwide will comply with visitors' "Do Not Track" preferences starting later this year, the company have announced.

Most major browsers are now able to send a message to sites visited, indicating whether users want their surfing behaviour to be tracked by cookies for the purposes of displaying personalised ads. In February the last major hold-out, Google, announced that its Chrome browser will include Do Not Track support by the end of the year.

That message, an HTTP (hypertext transfer protocol) header accompanying a request to display a web page, avoids the awkward paradox that to store a visitor's preference not to be tracked by cookies, sites had to store a cookie containing that preference, and provides a consistent way to store and indicate such preferences across all websites that respect the Do Not Track header.

Yahoo said that support for the Do Not Track header has been in the works since last year. All Yahoo sites will respect the header, including those of Right Media and Interclick, two Yahoo subsidiaries specialising in behavioural or data-driven advertising, the company said.

The company's announcement comes the same day that the US House of Representatives' Subcommittee on Commerce, Manufacturing, and Trade is set to hold a hearing on balancing privacy and innovation, and in the same week that the US Federal Trade Commission called for creation of a Do Not Track tool for internet users.

In a statement announcing its plans for allowing visitors to opt out of tracking, Yahoo maintained that allowing advertisers to regulate themselves was the best and quickest way to introduce protections to the market place without sacrificing innovation or value creation.

Yahoo said its Do Not Track system meets the recommendations of the Digital Advertising Alliance (DAA), an industry body uniting many advertisers and online advertising networks.

Such self-regulatory programmes, though, have been criticised for leading to opt-out systems that favour advertisers and are too difficult for ordinary consumers to use. The DAA's online opt-out management tool was one of several that had inappropriate default settings and major usability flaws, according to an October 2011 study at Carnegie Mellon University, "Why Johnny can't opt out: A usability evaluation of tools to limit online behavioral advertising."

Yahoo is one of the first household names to announce its commitment to honoring the Do Not Track header, according to a list of companies having announced such commitments maintained by researchers at Stanford University.