CTV Ad Portfolio: NonLinear extended to Pause/Screensaver/Overlay/Squeezeback, standardized QR Code, AdCOM plcmt/pos/playbackmethod/attr signaling
77 elements · 51 attributesBrowse element catalog →
VAST section navigation
VAST
2.0 → 4.4 · 4.4VAST (Video Ad Serving Template) is the XML response standard published by IAB Tech Lab, defining the ad serving and tracking contract between ad servers and video players. The in-site element skeleton covers 2.0 → 4.4; all data is vendored from the official IAB GitHub repositories and cross-checked.
On this page
How it works: carrying and parsing a VAST response
VAST defines the 'what does the ad return, what does the player execute' contract: the requester receives a VAST XML document and, per its declarations, selects media, fires tracking requests at the right moments and drives interaction. In the OpenRTB chain the VAST document is carried as a string in BidResponse.adm (imp.video / imp.audio), sharing one element definition with the direct tag-URL flow.
- Serving side · ad server / SSPProduces the VAST XML: declares one or more Ad under VAST/@version, each choosing between InLine and Wrapper — InLine carries the full placement inline, Wrapper carries only a VASTAdTagURI plus its own tracking nodes. The creative layer splits via Creatives/Creative into the Linear, NonLinear and CompanionAds delivery forms.
- Playback side · video player / rendering layerParses and executes: picks one media candidate from MediaFiles/MediaFile by type, width/height, bitrate and delivery; requests Impression, TrackingEvents/Tracking, VideoClicks, ViewableImpression and AdVerifications resources at the matching moments; @skipoffset, Icons and Companion@renderingMode are interpreted by the player.
Four contract points
- Version declaration — VAST/@version states the document version and the parser interprets elements and attributes accordingly. The in-site skeleton records the existence range of every element and attribute across 2.0 → 4.4 via since/until.
- Wrapper recursion — a Wrapper points at the next tag through VASTAdTagURI, and its own Impression and Tracking must still be reported in order after the inner InLine resolves; further recursion is governed by followAdditionalWrappers, allowMultipleAds and fallbackOnNoAd (introduced in 3.0).
- Tracking is keyed by event — TrackingEvents/Tracking carries the official event name in @event, with an extra @offset for progress events (3.0+). The attribute is a string rather than an enumeration in the XSD, so the site does not invent a value list; the event names follow the official spec text.
- Extension and verification slots — Extensions/Extension carries proprietary content (xs:any); from 4.4 the AdCOM-normalized signals plcmt, pos, playbackmethod and attr are cataloged beneath it. Third-party measurement resources ride in AdVerifications/Verification (4.0+).
Document structure
The backbone of the VAST 4.4 skeleton (parentheses give cardinality and version range); element names are clickable and jump to that node in the version catalog, expanding its ancestors.
- VAST0..1
- Ad0..*
- InLine0..1
- Impression1..*
- ViewableImpression3.0+0..*
- AdVerifications4.0+0..1
- Creatives1
- Creative0..*
- Linear0..1
- MediaFiles1
- TrackingEvents0..1
- VideoClicks0..1
- NonLinearAds0..1
- CompanionAds0..1
- Wrapper0..1
- VASTAdTagURI1
- Extensions0..1
Version timeline
No structural changes: macros moved to GitHub maintenance, [PLAYBACKMETHODS]=7 continuous play, inline data URIs for InteractiveCreativeFile
68 elements · 48 attributesBrowse element catalog →
SIMID interactive creatives, Creative@adType, IconClickFallbackImages
68 elements · 48 attributesBrowse element catalog →
OMID integration (browserOptional), audio ads (adType), AdServingId, Expires, removal of VPAID/Flash
66 elements · 48 attributesBrowse element catalog →
Mezzanine files, UniversalAdId, AdVerifications framework, Category, separation of media and interactive files
59 elements · 42 attributesBrowse element catalog →
Skippable ads (skipoffset), Ad Pods, Icons, expanded error codes and tracking events
52 elements · 36 attributesBrowse element catalog →
Baseline: Linear / NonLinear / Companion and quartile tracking (much legacy traffic still targets this baseline)
37 elements · 17 attributesBrowse element catalog →
Data sources & baseline
Official data vendored from the IAB repositories InteractiveAdvertisingBureau/vast.git (commit e0858cd) and InteractiveAdvertisingBureau/VAST4.x.git (commit ccf49aa), fetched on 2026-08-19.
License: THE STANDARDS, THE SPECIFICATIONS, THE MEASUREMENT GUIDELINES, AND ANY OTHER MATERIALS OR SERVICES PROVIDED TO OR USED BY YOU HEREUNDER (THE “PRODUCTS AND SERVICES”) ARE PROVIDED “AS IS” AND “AS AVAILABLE,” AND IAB TECHNOLOGY LABORATORY, INC. (“TECH LAB”) MAKES NO WARRANTY WITH RESPECT TO THE SAME AND HEREBY DISCLAIMS ANY AND ALL EXPRESS, IMPLIED, OR STATUTORY WARRANTIES, INCLUDING, WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AVAILABILITY, ERROR-FREE OR UNINTERRUPTED OPERATION, AND ANY WARRANTIES ARISING FROM A COURSE OF DEALING, COURSE OF PERFORMANCE, OR USAGE OF TRADE. TO THE EXTENT THAT TECH LAB MAY NOT AS A MATTER OF APPLICABLE LAW DISCLAIM ANY IMPLIED WARRANTY, THE SCOPE AND DURATION OF SUCH WARRANTY WILL BE THE MINIMUM PERMITTED UNDER SUCH LAW. THE PRODUCTS AND SERVICES DO NOT CONSTITUTE BUSINESS OR LEGAL ADVICE. TECH LAB DOES NOT WARRANT THAT THE PRODUCTS AND SERVICES PROVIDED TO OR USED BY YOU HEREUNDER SHALL CAUSE YOU AND/OR YOUR PRODUCTS OR SERVICES TO BE IN COMPLIANCE WITH ANY APPLICABLE LAWS, REGULATIONS, OR SELF-REGULATORY FRAMEWORKS, AND YOU ARE SOLELY RESPONSIBLE FOR COMPLIANCE WITH THE SAME, INCLUDING, BUT NOT LIMITED TO, DATA PROTECTION LAWS, SUCH AS THE PERSONAL INFORMATION PROTECTION AND ELECTRONIC DOCUMENTS ACT (CANADA), THE DATA PROTECTION DIRECTIVE (EU), THE E-PRIVACY DIRECTIVE (EU), THE GENERAL DATA PROTECTION REGULATION (EU), AND THE E-PRIVACY REGULATION (EU) AS AND WHEN THEY BECOME EFFECTIVE.
IAB Tech Lab VAST standards page ↗
Element data on this page is generated from the in-site skeleton (data/vast-spec/skeleton/vast.ts); its consistency with official sources is guarded by bidirectional CI cross-checks. Every divergence from the official XSD/spec is registered with factual grounding.