YOUTUBE is sticking even longer ads that can't be skipped in tons of videos across its site.

The Google-owned platform is expanding its "non-skippable" adverts that run before videos to all creators, meaning they'll start popping up before a lot more content in the coming weeks and months.

It sneakily buried the controversial update in a video titled "Want to earn more money from ad revenue?" on its official Creator Insider channel last week.

The move would force users to sit through video ads of up to 15-20 seconds when watching clips from channels great and small.

That's up to four times longer than the current five second viewing time for the company's regular ads that can be skipped.

Google said the feature would help vloggers and other creators rake in more money from advertisers looking to promote their brands, but not everyone is convinced.

The comments section of the video announcing the changes is flooded with messages slamming the update as a potential turn-off for viewers.

"Nonskippable ads will make viewers very unhappy," said one user.

"Non-skippable ads are unlikely to make us more money. It will simply drive more people to use AdBlock and we will end up making less money. I don't see this as a good idea," noted another.

In its video announcing the changes, a YouTube spokesperson explained the differences between the two types of ads on its service:

"We have the type that viewers can skip, which you probably see a lot. There's another kind that viewers can't skip," he said.

"The [change] is the ability to turn on non-skippable ads for your videos. In the past it's been something that's only been available to a select few partners. In about a week from now we're going to start rolling it out to everyone who's in the YouTube partner programme.

"The number one reason is more money. Non-skippable ads tend to make more money because generally advertisers are willing to pay a bit more for them."