X Ad Specs, Checked Against the Source

Post copy is 280 characters, and any link costs 23 of them regardless of length. Images are PNG or JPEG at a maximum of 5MB, six times tighter than Meta. Video is MP4 or MOV up to 1GB, though X recommends under 30MB. All of it is from X's own specs page, checked 21 August 2026.

The 5MB image limit is the one that catches people moving over from Meta. An asset that uploads fine to Facebook will be rejected here.

Text and post copy

This applies across every Promoted Ad format, and the link arithmetic is the part worth internalizing.

X states that each link reduces the character count by 23 characters. That is a flat cost: a short link and a long link both take 23. There is no advantage to shortening a URL.

Plan for 257 rather than 280 on anything with a destination, which is most advertising.

Image ads

Three things here trip people up.

5MB is the whole budget. Meta allows 30MB. If your workflow exports high-quality PNGs for Meta and reuses them here, expect failures. Export JPEG at a sensible quality for X.

GIFs become static. If you upload a GIF as an image ad, the animation is discarded. Use a video ad if you need movement.

No BMP or TIFF. Stated explicitly, which suggests people try.

Video ads

Two of those deserve more than a table row.

Videos under 60 seconds loop. That is a genuine creative constraint rather than a technical note. A 45 second video restarts, so an ending that resolves cleanly into the opening frame plays as a loop rather than as an awkward restart. Very few advertisers design for this and it is free to use.

The logo goes upper left. X states this explicitly, and it is unusual for a platform to be that prescriptive. Follow it.

On frame rate, X adds a sensible instruction that most specs pages omit: if your source has a lower frame rate, do not upsample it. Interpolating 24fps footage to 30 makes it worse, not more compliant.

Vertical video ads

These run in X's Immersive Media Viewer, reached through the Video tab or by tapping an organic video to full screen.

X also lists the other accepted ratios with exact pixel dimensions, which is more specific than most platforms bother to be:

Worth noticing that 4:5 at 1440 x 1800 is identical to Meta's recommended feed dimensions. That is the one asset that travels between the two platforms without a re-export.

Carousel ads

Carousels accept the same six aspect ratios listed above, with the requirement that a single carousel uses one ratio throughout.

The mixed media rule is the one to design around: if you combine images and video in one carousel, a 1:1 image must pair with a 1:1 video. You cannot mix ratios within a carousel.

Note also that X allows six slides against Meta's ten, and the recommended dimensions are considerably smaller than Meta's 1080 x 1080.

Conversation buttons and polls

Two standard features that can be added to Promoted Ads, both with their own character limits.

Conversation buttons prompt someone to post about your brand, with a pre-populated message they can edit.

Conversation buttons must be paired with an image or video.

Polls add two to four options to an ad.

One useful detail: poll option text does not count against the 280 character post copy. You get the full post plus up to 100 characters of options.

Poll duration starts when the post is created rather than when it is promoted, which is a scheduling trap worth knowing.

Amplify: pre-roll and sponsorships

Amplify places your video against publisher content. Both variants are similar with one meaningful difference in recommended length.

X notes that 1:1 renders the same on desktop and mobile, timeline and profile, and that 1:1 and 9:16 occupy more screen than 16:9.

Both formats carry publisher overlays in the top left and bottom corners for previews and ad countdowns, so keep those areas clear.

For sponsorships, X states that any height is acceptable but a video taller than it is wide will be cropped to 1:1 in the feed.

X Live

If you are streaming, the recommended encoder settings.

The event page description takes 280 characters and can contain external links, which X flags as a newer capability. An event carousel supports up to five videos and requires additional investment.

Spotlight takeover

Placed in the Explore tab. Worth including because the character limits are unusually tight and the content rule is easy to miss.

The rule people miss: the Spotlight placement is not age-gated, so X requires the creative to be appropriate for all ages, explicitly ruling out weapons, nudity and violence.

Creative must be delivered as a darkpost with media only. Card formats are not accepted.

X also advises against click-bait phrasing in the description, naming discount and limited-time language specifically.

What is actually available to you

X states plainly at the top of its specs page that not all listed formats are available to self-serve advertisers.

Amplify, Live, Takeovers and Branded Notifications generally require an Account Manager. If you are running X ads through the self-serve interface, the formats that concern you are Text, Image, Video, Vertical Video and Carousel, plus conversation buttons and polls as add-ons.

That is worth knowing before planning a campaign around a format you cannot buy.

How X compares to Meta

The differences that change your workflow rather than the ones that are merely different.

The 5MB image ceiling is the practical headline. Everything else is a difference you adapt to once; that one will bite repeatedly if your export presets were built for Meta.

The good news is 4:5 at 1440 x 1800, which both platforms accept, so a single vertical asset can serve both.

I have the equivalent Meta reference in the Meta ad specs post.

What specs will not fix

Whether the campaign works, which is where the money actually goes.

X is a narrower proposition than Meta for most businesses, and the platform question should be settled before the creative question. I went through who it genuinely suits in the post on whether X is worth it: B2B technology and finance, anyone whose customers include journalists, and businesses with someone who genuinely enjoys posting there.

If your audience is not in one of those groups, perfectly specified ads will still underperform, and the fix is not in this document.

The other two things that outrank every number here: what conversion event your campaign optimizes for, and whether the budget is concentrated enough to gather data. Those are in the metrics post and the ad budget guide, and they apply on every platform.

How to keep this current

Assume it goes stale, including this page.

X changes these without announcement, and the specs page is the source. It takes a minute to check before a build, which is less time than a rejected upload costs.

This page was checked against X's creative specs page on 21 August 2026. If you are reading it much later, verify before you build.

What to do on Monday

Check the file size of the images in your current X campaigns. If any are near 5MB, they are one export setting away from failing.

Then look at any video under 60 seconds and ask whether its ending sits well against its opening, because it is going to loop whether you designed for that or not.

FAQ

What are the current X ad specs? Post copy is 280 characters, reduced by 23 for each link. Images are PNG or JPEG up to 5MB. Video is MP4 or MOV up to 1GB, with 15 seconds or less recommended and 2:20 supported. Carousels take 2 to 6 slides. Checked 21 August 2026.

What size can an X ad image be? Maximum 5MB, in PNG or JPEG. BMP and TIFF are not accepted, and an uploaded GIF renders as a static image. That 5MB ceiling is six times tighter than Meta's 30MB.

How long can an X video ad be? 15 seconds or less is recommended and up to 2 minutes 20 seconds is supported. Select advertisers can request up to 10 minutes, with 9:55 advised. Videos under 60 seconds loop.

How many characters can an X ad have? 280 characters of post copy, but each link costs 23 characters regardless of its length, so plan for 257 on anything with a destination. Poll options are extra and do not count against the 280.

Are all X ad formats available to everyone? No. X states that not all formats are available to self-serve advertisers. Amplify, Live, Takeovers and Branded Notifications generally require an Account Manager.

About the author

Adam Palmer is President of Inertia Digital Marketing, a digital marketing agency working with clients from small business to multi-location enterprise and franchise operations. Across 15 years he has managed more than $50 million in paid digital campaigns, and he writes here about what actually moves numbers rather than what sounds good in a strategy deck. Inertia built and maintains Social Fonts, which is free and always will be.