What's X (Twitter) Ads' Default Attribution Window?

X (formerly Twitter) Ads defaults to a 30-day post-engagement attribution window and a 1-day post-view attribution window, according to X's own conversion-tracking documentation. Post-engagement credits a conversion when someone likes, reposts, replies to, follows, or clicks a Promoted Ad and then converts within the window; post-view credits a conversion when someone simply sees an ad, doesn't interact with it, and converts later anyway.

What Post-Engagement and Post-View Actually Measure

Post-engagement attribution is the wider net: it counts any interaction with a Promoted Ad — a like, a repost, a reply, a new follow, or a link click — as the starting point for the attribution clock. Post-view attribution is narrower and more conservative: it only fires when a person scrolled past an ad without touching it, then converted anyway, which X still treats as partial credit for exposure.

Why 30 Days Is the Default, Not the Only Option

X lets advertisers shorten or lengthen both windows. The post-engagement window can be set to 1, 2, 3, 5, 7, 14, or 30 days; the post-view window offers the same choices, plus the option to turn post-view attribution off entirely. X recommends the 30-day engagement window and the 1-day view window as defaults, but a campaign built around impulse purchases doesn't need a 30-day tail, and a campaign built around a considered B2B sale might want to keep the full 30 days rather than shrink it.

The Tradeoff of Leaving the Default Alone

A 30-day engagement window reports more conversions than a 7-day one, simply because it catches more of the customer journey — but more conversions attributed to X doesn't mean X caused more of them. Anyone comparing X's reported conversion numbers against another platform's dashboard should first check whether both platforms are using matched attribution windows, or the comparison is measuring two different definitions of a conversion, not two different levels of performance.

What to Set If You're Not Sure

Match the attribution window to your buying cycle, not to X's default. An ecommerce brand selling a $30 impulse item is well served by a 7-day engagement window and a 1-day view window — anything longer just accumulates conversions X had little to do with. A B2B software company running a multi-week sales cycle is better served leaving the 30-day engagement window in place, since a lead who clicked an ad three weeks before signing up genuinely did start that journey on X.

One More Wrinkle: Cross-Device Attribution

X also attributes conversions across devices when a user is logged into the X app on one device and completes a purchase on another, using logged-in identity rather than a device cookie — which is part of why X's reported numbers can diverge from a browser-based analytics tool that only sees same-device activity.

Bottom Line

Leave X Ads on its 30-day post-engagement and 1-day post-view defaults only if your sales cycle actually runs that long; otherwise, shorten the engagement window to match how quickly your customers actually buy, and confirm any cross-platform comparison you're making uses matching windows on both sides.

Sources: X Business (formerly Twitter Ads) Help Center, "Conversion Tracking for Websites."