What are outstream video ads, and how do buyers verify them?
Part of Programmatic media planning
The short answer
Outstream video ads are video ads that play outside a stream of video content the reader asked to watch, for example between paragraphs of an article or in a feed. In OpenRTB 2.6 the seller labels each video impression with a plcmt value. Only value 1, Instream, describes sound on video that is the focus of the visit.
Key takeaways
- IAB Tech Lab's 2022 video guidelines describe out-stream ads as video served alone for display, usually on a web page, and not the focus of the visit.
- OpenRTB 2.6-202303, released in April 2023, deprecated the old placement field and added plcmt, whose values follow the updated IAB Tech Lab definitions.
- Under plcmt, Instream requires sound on by default or a clear intent to watch, and the video content must be the focus of the page.
- A deal or rate card that calls inventory instream should be checked against the plcmt and playbackmethod values the seller actually sends.
What is an outstream video ad?
Definition
- Outstream video ad
- A video ad that runs without the streaming video content a reader chose to watch, or beside content that is not the focus of the visit: in an article, a feed, a display slot, a slideshow or a floating player.
IAB Tech Lab's Ad Format Guidelines for Digital Video and CTV (opens in a new tab), released in August 2022, draw the line plainly. In-stream ads are streamed as part of a video that plays in a player, while out-stream video ads are ads in video format but served alone for display, usually on a webpage. The guidelines list the names the market has used for out-stream: in-banner video, in-page video, rich media with video, video interstitial, incentivized video and in-feed video.
The same document says out-stream units are not the focus of the page and are not part of a video experience in a player app or on connected TV. That is the practical test on any site: if the reader came for a recipe and a player starts beside the third paragraph, the ad is outstream.
Outstream is not a lesser format by definition. It reaches readers on text publishers with no video library of their own. The problems start when it is sold, priced or reported as instream, because the two carry different expectations about sound, attention and intent.
How does OpenRTB 2.6 classify video placements?
Every video impression in an OpenRTB 2.6 (opens in a new tab) bid request carries a Video object. Its plcmt field is described as the video placement type for the impression, and its values live in the AdCOM list called Plcmt Subtypes, Video. The AdCOM specification (opens in a new tab) defines four core values for web and app video, summarized below in plain words with the spec's key conditions kept intact.
| plcmt value | Spec name | What the definition requires | Instream or outstream for a buyer |
|---|---|---|---|
| 1 | Instream | Pre-roll, mid-roll or post-roll around video the consumer requested; sound on by default at player start or a clear intent to watch; the video is the focus of the visit and the only in-view player capable of audio | Instream |
| 2 | Accompanying Content | Pre-roll, mid-roll or post-roll around video content in a player that sits before, between or after text or graphics, and starts only when it enters the viewport; may float when scrolled | Not instream: the video accompanies a page whose focus is other content |
| 3 | Interstitial | Video ad without video content that is the primary focus while it plays, takes most of the viewport and cannot be scrolled out of view, as in app video or slideshows | Outstream, full screen |
| 4 | No Content/Standalone | Video ad played without streaming video content, in slideshows, native feeds, in-content slots or sticky and floating units | Outstream, the classic in-article or in-feed unit |
The AdCOM release of July 16, 2026 updated the ad format signaling lists, and the list now continues past value 4 with Pause, Screensaver, Overlay, Squeezeback and In-scene, formats that mostly describe streaming players. For open web planning the four core values carry the decision. Two other Video fields matter: playbackmethod says how the ad starts (2 is sound off without user interaction, 6 is sound off on entering the viewport), and w and h give the player size.
Why did the plcmt field replace older placement values?
The older field was called placement. In the OpenRTB 2.5 specification (opens in a new tab) its list had five values: 1 In-Stream, 2 In-Banner, 3 In-Article, 4 In-Feed and 5 Interstitial, Slider or Floating. In-Stream was defined as video played before, during or after the streaming video content that the consumer has requested. That definition said nothing about sound or about whether the video was the reason for the visit, so an article page with a small autoplaying player could be sent as value 1.
The 2022 Ad Format Guidelines tightened the rule. To count as in-stream, placements must be set to sound on by default at start, and impressions with sound off by default must signal an out-stream placement value. The guidelines warn that in-display video classified as in-stream may not serve properly and may cause performance issues for the publisher and the viewer.
OpenRTB release 2.6-202303 (opens in a new tab), published on GitHub on April 5, 2023, added plcmt and deprecated placement. The implementation guide (opens in a new tab) shows a seller sending both: an in-stream player sends placement 1 and plcmt 1, while an in-article player sends the legacy placement 3 with plcmt 4. Filter on plcmt.
How do outstream and instream video differ for buyers?
The difference shows up in the creative, the price, the measurement and the claim made to the client. Treat the two as separate line items even when one publisher sells both.
| Planning question | Instream | Outstream |
|---|---|---|
| Reader intent | The reader chose to watch the video content | The reader came for text, images or a feed |
| Sound at start | On by default, or a clear user intent to watch | Can start muted; check playbackmethod for values 2 or 6 |
| Creative | Built for sound and a full message in sequence | Has to work silently, with captions and an early brand frame |
| Strengths | Attention and sound by design; clear industry definition | Wide reach on editorial sites; contextual fit with the article |
| Weak points | Scarce on smaller publishers; misclassified article players dilute it | Sound off, easy to scroll past; sticky versions can annoy readers |
| Claim to the client | Can be called instream when plcmt is 1 | Should be reported as outstream, never folded into an instream total |
Pricing claims follow the same split. A seller quoting instream rates should show that the deal's impressions carry plcmt 1 with a sound on playback method. If sampled bid requests show plcmt 4 or playback method 6, the inventory may still be worth buying, at an outstream rate and under an outstream line. The bid request guide shows where these fields sit.
Which quality checks apply to outstream video?
Outstream quality is mostly about how the player behaves on the page. The Coalition for Better Ads (opens in a new tab) lists auto-playing video ads with sound on desktop and mobile, and on mobile, sticky pop-out video ads (opens in a new tab) that start inline and then move to the bottom of the viewport, where they obstruct the content. Its methodology has not yet tested pre-roll and mid-roll ads around video relevant to the page.
Outstream checks before a site or deal joins the plan
- Sampled bid requests or the deal sheet show the plcmt value, and the line item name matches it.
- Players marked as sound off (playbackmethod 2 or 6) are not sold or reported as instream.
- The player starts only when it enters the viewport, as the Accompanying Content definition requires, not on page load below the fold.
- No player auto-plays with sound, a pattern the Coalition for Better Ads lists for desktop and mobile.
- On phones, a floating player does not cover the article while the reader scrolls, and a close control is visible.
- Pages with a sticky video unit stay within the desktop ad density experience the coalition describes for sticky video, more than 30 percent of the page height.
- The viewability method states whether it measures the ad's pixels or the player's pixels, as the MRC mobile guidelines ask.
Measurement needs its own check. The MRC mobile viewable guidelines (opens in a new tab) apply their video criteria to in-stream and stand-alone (out-stream) ads and count 50 percent of the ad's pixels; a vendor using the player's pixels instead should disclose it prominently. The MRC digital video impression guidelines (opens in a new tab) add disclosure expectations for auto-play in-banner video. See also viewability and ad density.
How does PlacementGraph help screen sites before outstream video runs?
What does an outstream review look like on a real plan?
Fictional example
A residential garage door maker in Ohio
A fictional Columbus maker of insulated garage doors plans a spring video flight in Ohio, focused on Columbus, Cleveland and Cincinnati, in English. The agency is offered a home improvement deal described as premium instream video across a group of renovation and do it yourself publishers.
The planner asks the seller for sample bid requests and finds two kinds of impression. Videos on the group's how to channel pages arrive with plcmt 1 and playback method 3, click to play with sound on. Players placed between paragraphs of written project guides arrive with plcmt 4 and playback method 6, sound off on entering the viewport.
The plan splits the offer into two lines, instream on the video pages and outstream on the article pages, each with its own creative. The outstream line gets a captioned cut that shows the door and the brand in the first frames. Two article sites drop out after a phone review shows a floating player covering the text with no close control.
Frequently asked questions
Is in-banner video the same as outstream video?
In-banner video is one form of outstream. IAB Tech Lab's 2022 guidelines list in-banner video among the out-stream terms. The MRC says banner ads with video embedded in them are generally covered by the display criteria for viewable impression measurement, so a video playing in a 300 by 250 slot is measured as display, not as instream video.
Can outstream video be bought through a private marketplace deal?
Yes. A deal can carry any plcmt value the seller sends. Ask which values the deal will include before it is set up, and name the plan line by that value. A deal mixing plcmt 1 and plcmt 4 makes it hard to report either one honestly to the client.
Do outstream video ads need a different creative?
Plan for it. Outstream players can start without sound, so the creative has to work silently: captions or on screen text, the brand early, and a product image that reads at a small size. The w and h values in the bid request show the player sizes the creative must work at.
Does a sticky or floating player change the plcmt value?
Not by itself. The AdCOM definitions say an Instream player that converts to floating should send the updated player size on later ad calls, and an Accompanying Content player may float as it scrolls off the page. The value follows the page's focus and how playback starts, not whether the player moves.
Sources
- Ad Format Guidelines for Digital Video and CTV (August 2022) (opens in a new tab)IAB Tech Lab
- OpenRTB 2.6 specification, Object: Video (opens in a new tab)IAB Tech Lab on GitHub
- AdCOM 1.0, List: Plcmt Subtypes, Video and List: Playback Methods (opens in a new tab)IAB Tech Lab on GitHub
- OpenRTB 2.x releases, including 2.6-202303 (opens in a new tab)IAB Tech Lab on GitHub
- OpenRTB 2.6 implementation guide, 7.10 Updated Video Signals (opens in a new tab)IAB Tech Lab on GitHub
- OpenRTB API Specification Version 2.5 (opens in a new tab)IAB Tech Lab
- Mobile Viewable Ad Impression Measurement Guidelines (June 28, 2016) (opens in a new tab)Media Rating Council and IAB
- Digital Video Impression Measurement Guidelines, version 1.1 (June 2018) (opens in a new tab)Media Rating Council and IAB
- Better Ads Standards (opens in a new tab)Coalition for Better Ads
- Ad Experience: Mobile Sticky, Pop-Out Video Ads (opens in a new tab)Coalition for Better Ads
Researched and written by PlacementGraph Research. Read how we research, source and update these pages. Corrections: diana@placementgraph.com.