YouTube will begin providing advertisers with data on how many of their ads are viewable to users of the streaming video service, in response to growing concerns over viewability.

According to the Financial Times, the company plans on allowing third-party verification groups to insert code into YouTubes coding, enabling advertisers to collect data on the position and context of ads.

Brands including Unilever and Kellogg have been among those making complaints as viewability becomes an increasingly pressing concern among online advertisers.

The sources cited in the report did not specify whether the coding would also be added to YouTubes mobile apps, which would tend to have higher viewability figures thanks to the nature of mobile, but given the growth of mobile video consumption, one can expect the tools to be rolled out across YouTubes entire ecosystem.

The ability to verify viewability is expected to be available by the end of the year, and will likely attract verification companies such as ComScore, Integral Ad Science and DoubleVerify, who will be able to use existing tools to let advertisers know exactly how many of their ads are being seen.

“Were committed to meeting all of our clients measurement needs through a combination of product innovation and industry partnerships,” said a YouTube spokesperson, who also said that the company was “taking our clients feedback into account as we continue to roll out new solutions.”

“Its great that Google is considering this move for its YouTube brand,” said Tim Hussain, product strategy director at Collective. “It helps the integrity of the industry to be more measurable in this medium, and is in the best interest of advertisers.

“The big remaining question is why each tech vendor has a different version of the numbers. The challenge for the industry is to agree on a single quantifiable measure for video viewability. Whose numbers should we be working to?”