Creative Formats & Assets

Bumper Ads vs Outstream Ads: On-YouTube Reach or Off-YouTube Reach

In short: Both are cheap, impression-priced ways to add video reach on top of a core buy, but they draw from completely different inventory. Bumper ads run only on YouTube itself, forcing six seconds before or during content people are already watching there. Outstream ads run only off YouTube, auto-playing muted inside articles and apps on Google's video partner network, and they're charged only once the ad has actually been visibly playing. Bumpers add frequency inside YouTube; outstream adds incremental reach beyond it. Stay on YouTube with bumpers for a captive, sound-available audience; go outstream when the goal is cheap extra reach across the mobile web.

By the AdFlint research team · Fact-checked against current Google and Meta platform behavior · Last reviewed July 2026

Bumper Ads

Six-second non-skippable YouTube video ads sold on impressions, designed to land a single message before the content plays.

The length is fixed and unskippable, so the unit works as a frequency and recall builder rather than a way to explain anything. It is often paired with a longer skippable ad in the same campaign to reinforce it. The mistake is cutting a thirty-second commercial down to six seconds; the format needs one idea, written for six seconds from the beginning.

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Outstream Ads

Mobile-only video ads that play muted inside articles and apps on Google video partner sites, entirely outside YouTube itself.

The unit auto-plays without sound as someone scrolls, unmuting only on tap, and is billed on viewable CPM once it has been visibly playing for two seconds. It buys cheap incremental video reach beyond YouTube inventory. The mistake is expecting YouTube-quality attention: creative has to work silently with captions, and these impressions should be judged on reach rather than in-stream click-through.

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Side by side.

The differences that actually change what happens in your account.

	Bumper Ads	Outstream Ads
Where it runs	Inside YouTube itself, in the standard video player.	Outside YouTube entirely, inside articles and apps on Google video partner sites.
Device eligibility	Any device where YouTube plays - desktop, mobile, tablet, connected TV.	Mobile and tablet only.
Playback trigger	Auto-plays as part of the content stream the viewer chose.	Auto-plays muted as the viewer scrolls the page, unrelated to any video they chose to watch.
Sound on start	Whatever the player's existing sound state is.	Muted by default, unmuted only if the viewer taps it.
What triggers a charge	Every impression, on a CPM basis.	Only impressions that were visibly playing for a couple of continuous seconds, on a viewable CPM basis.
Skip behavior	Cannot be skipped for the full six seconds.	Scrolls out of view whenever the viewer keeps scrolling - there's no dedicated skip control to interact with.
Creative requirement	Works with sound, built for a captive in-player audience.	Must work silently with captions, since most impressions are watched muted.
Failure mode	Trimming a longer ad down instead of writing for six seconds.	Expecting YouTube-level attention and judging it on in-stream click-through instead of reach.

What actually separates them.

Bumper ads only draw impressions from within YouTube's own player; outstream ads only draw impressions from partner sites and apps entirely outside YouTube.

Bumper ads charge for every impression served; outstream ads charge only for impressions that were actually visibly playing for a couple of continuous seconds.

Bumper ads assume the viewer's existing sound setting; outstream ads default to muted and rely on captions to carry the message.

Bumper ads are eligible on any YouTube-capable device including connected TV; outstream is restricted to mobile and tablet.

Bumper ads sit inside content the viewer actively chose to watch; outstream ads appear inside a page the viewer is scrolling for an unrelated reason, so attention starts lower by design.

Which one should you use?

Use Bumper Ads when

You want reach specifically among people already on YouTube watching video content.
Your creative depends on sound to land the message.
You need connected TV or desktop reach, not just mobile.
You're comfortable paying for every impression rather than only viewable ones.

Use Outstream Ads when

You want incremental video reach beyond what YouTube alone can deliver, at a low cost per impression.
Your budget and goals are reach-focused rather than click or conversion-focused.
Your creative already works as a silent, captioned video, or you're willing to build one.
Your audience is primarily on mobile, since outstream doesn't run on desktop or connected TV.

Common questions.

Do outstream ads ever run on YouTube?

No. Outstream is specifically designed to extend video reach onto Google's video partner network of articles and apps, not onto YouTube itself. If you want reach on YouTube, that's bumper, in-stream, in-feed, or Shorts inventory instead.

Why does my outstream campaign show fewer impressions than I paid for?

You're only charged for viewable impressions - ones that actually played for a couple of continuous seconds while visible on screen - so served impressions that scroll past too fast or never render properly aren't billed. That's the point of viewable CPM: it filters out impressions nobody had a real chance to see.

Can I run bumper and outstream ads in the same campaign?

They live in different Video campaign subtypes with different required bid strategies, so you'd typically run them as separate campaigns or line items even if they're part of the same broader plan. Combining their reach in reporting means adding the two together yourself rather than reading one blended number.

Or stop choosing between them.

AdFlint picks the setting, writes the ads, and keeps optimizing inside the Google and Meta accounts you already own.

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