VAST Tester
Test your VAST ad tags with our interactive tester. Supports VAST 3.0 (VPAID) and VAST 4.2 (SIMID).
Event Log
No events yet. Test an ad to see events here.
From the team behind this tester
Turn Your Next VAST Tag Into Rich Media
Clipflip adds an interactive layer to a standard video ad: countdowns, live store maps, 3D colour pickers, product sliders. It still ships as a VAST tag, so it runs through Adform, DV360 or Xandr like any other campaign. Our team builds it, or yours does in Clipflip Studio as you grow.
- 1.72% Average CTR across 20 industries in 2025
- 800+ Rich media video ads our team built in 2025
- 300k Impressions free on your first campaign
VAST Tag Questions
VAST (Video Ad Serving Template) is the IAB standard that tells a video player which ad to play. A VAST tag is a URL that returns an XML file with the video files, duration, click-through URL and the tracking pixels for impressions, quartiles and clicks. Ad servers like Adform, Google Campaign Manager 360 and Xandr generate these tags, and video players and SSPs read them.
Paste the tag URL into the field above and click "Test Ad". The tester loads it with the Google IMA SDK, which many publisher players use, plays the ad and logs every event it fires: load, start, quartiles, clicks, completion and errors. If the ad plays through and all three quartiles show up in the log, your tag is working.
The most common causes are an empty response (no fill, often because of targeting or a frequency cap), a wrapper chain that redirects too often or times out, a media file the browser can't play, or an ad server that blocks requests from other domains. Some environments also refuse VPAID creatives. The error message in the event log points you in the right direction, for example VAST error 303 (no ad returned) or 403 (no supported media file).
Both let a video ad carry interactive elements. VPAID, used with VAST 3.0, runs the ad's own JavaScript inside the player, which gave creatives full control but also caused performance and security problems, so many platforms now restrict it. SIMID, used with VAST 4.x, is the IAB's successor: the interactive layer runs in a sandboxed iframe on top of the video while the player stays in control of playback.
VAST 4 added a universal ad ID, mezzanine files for server-side transcoding, and a dedicated place for interactive creative files instead of mixing them into the media files. Later 4.x versions added ad verification for Open Measurement and SIMID support. VAST 3.0 is still widely supported, which is why many ad servers offer both.
Yes. With VPAID or SIMID, a VAST tag can carry an interactive layer on top of the video: countdowns, store locators, product sliders, 3D colour pickers or surveys. That's what Clipflip builds. The sample tag prefilled in the tester above is one of ours, and it ships as a normal VAST tag, so it runs through your ad server like any other video campaign.
