The first teaser for Avengers: Doomsday has leaked online — and it contains a massive spoiler about the new Marvel movie

Doomsday clock activated

· TechRadar

News By Tom Power published 16 December 2025

Plenty of information has leaked online pertaining to four Avengers: Doomsday teasers (Image credit: Walt Disney Studios/Marvel Studios) Share Share by:

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  • The first details about Avengers: Doomsday's various trailers have leaked online
  • One teaser has already been shared widely across the internet
  • Marvel is battling to keep the footage under wraps

Christmas has come early for Marvel fans after the first details about multiple trailers for Avengers: Doomsday leaked online.

Last weekend (December 13/14), rumors were rife that the comic book giant would release four (!) teasers for its much-anticipated superhero movie. Those emerged in the wake of speculation that Marvel would only release a single Doomsday trailer before the end of 2025, that it would run ahead of public screenings of Avatar: Fire and Ash, and that the Avengers 5 trailer's runtime had reportedly been revealed.

Now, fresh details have emerged about those teasers. According to news outlet Feature First, each preview will be shown before Avatar 3 for one week only over the next four weeks. So, teaser #1, which will debut alongside Fire and Ash when it arrived on December 17, would be available until December 23. Then, teaser #2 would run from December 24 to 30, and so on.

Marvel is desperately trying to stop people from spilling the beans about a major Doomsday spoiler (Image credit: Marvel Studios)

Clearly, Marvel and parent company Disney are aiming to generate further hype – if more was needed – for the Marvel Phase 6 film's arrival. Of course, exclusively showing the trailers before Avatar 3 will also help to bolster Disney's bottom line, as it will persuade the general public to watch Fire and Ash multiple times in order to see all four teasers.

That would be the case if information about said trailers hadn't already appeared online. Despite Marvel and Disney's best attempts to mitigate leaks, the sheer number of theaters the previews will have been sent to means it's nigh-on impossible to keep them under wraps. Eventually, somebody somewhere would reveal all – and that's exactly what's happened here.

I won't be posting links to pirated footage or screenshots of the first teaser. However, given that Marvel has issued numerous DMCA takedowns to anyone who's posted said files online, it's clear that they're genuine.

So, what do they show? I am about to discuss a huge spoiler about Doomsday's first trailer, and a couple of key details about its follow-up teasers. If you don't want to know more, head to my spoiler-free guide on what we know so far about Avengers: Doomsday right now, because absolutely massive spoilers immediately follow for the next Avengers film.

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