When you’re trying to get your ads seen online in 2025, especially on a platform like StackAdapt, it’s not just about having a cool picture or a catchy phrase. Seriously, it’s way more technical than you might think at first. We’re talking about specific display ad specs, and if you don’t get ’em right, your amazing ad might just… not show up. Or it’ll look goofy. And who wants their brand looking goofy? Nobody, that’s who.
So, getting this stuff down is super important. StackAdapt, being a big player in the programmatic advertising world, has its own quirks and requirements for display ads. It’s not like they’re just making rules to be difficult; these specs help make sure your ads load fast, look good on all sorts of screens (from tiny phones to giant desktop monitors), and honestly, don’t break the internet for folks trying to browse. It’s all about fitting into the digital space, you know?
The Basics: Image Ads Aren’t Just JPEG-ing Around
Let’s kick this off with the most common type: image display ads. These are your standard static banners. You’d think it’d be simple, right? Just upload a picture. But nope, there’s a list. StackAdapt supports JPEG, PNG, and GIF. PNG is cool for transparency, JPEGs are usually smaller files, and GIFs? Those are for little animations, but they have their own rules.
For static images, the file size is a big deal. Generally, you’re looking at something like 150KB for a single image. That’s not a lot when you’ve got high-res designs these days. So, you gotta compress your images without making them look pixelated and gross. I mean, nobody wants to see a blurry ad, do they? It just screams “I didn’t try very hard,” and that’s not the message you want to send.
And then there are the actual dimensions, which is where things get really specific. StackAdapt supports a whole bunch of standard IAB (Interactive Advertising Bureau) sizes. The most common ones, the ones you pretty much have to have if you want your ads everywhere, are:
300×250 (the “Medium Rectangle,” pretty much everywhere)
728×90 (the “Leaderboard,” often at the top of pages)
160×600 (the “Wide Skyscraper,” usually on the sidebars)
320×50 (for mobile, a smaller banner)
300×50 (another mobile one, sometimes called a “Smartphone Banner”)
320×480 (a “Mobile Interstitial,” takes up the whole screen for a sec)
970×250 (a “Large Leaderboard” or “Billboard,” big and in charge)
There are also a bunch of others like 300×600, 970×90, 250×250, and 120×600. Basically, the more sizes you provide, the better. It just means your ads can fit into more spots across different websites and apps. It’s like having a wardrobe with clothes for every occasion; you just fit in better.
My personal take is that a good campaign really needs at least the 300×250, 728×90, and 160×600 for desktop, and the 320×50 or 320×100 for mobile. If you only give StackAdapt one size, you’re really limiting where your ad can show up. And that seems like a missed opportunity, doesn’t it?
HTML5 Ads: Getting Fancy (But Not Too Fancy)
So, if static images are like a still photograph, HTML5 ads are more like a short, interactive clip. They’re super cool because they can have animations, little interactive bits, and generally just grab attention more than a plain picture. But with more coolness comes more rules, right?
StackAdapt supports HTML5, which is basically a zip file containing all your HTML, CSS, JavaScript, and image assets. For these, the file size limit is often a bit higher, sometimes up to 200KB or even 300KB for the initial load. But here’s the kicker: after that initial load, there might be a polite suggestion (or even a hard rule, depending on the exchange) for what’s called a “polite load” – basically, any extra stuff that loads after the ad initially appears should also be within a certain size, like maybe another 500KB or even a megabyte. This is to keep things from bogging down someone’s browser.
The dimensions for HTML5 ads are pretty much the same as static images. All those standard IAB sizes apply. What’s interesting is that you also gotta make sure your HTML5 creative has a click tag. That’s how StackAdapt knows where to send people when they click your ad. If your click tag isn’t set up right, your ad will just sit there, pretty but useless. And that’s a bad look.
Animation in HTML5 ads is awesome, but there are rules for that too. Usually, the total animation length should be kept under 30 seconds. And loops? Most ad exchanges only let your animation loop a couple of times, maybe three at most. You don’t want an ad that just keeps moving forever and ever, distracting people from the content they’re actually trying to read. It’s kinda annoying, actually.
Native Ads: Blending In (But Standing Out)
Native ads are a different beast entirely. They’re designed to match the look and feel of the website or app they’re on. So, instead of a banner, they might look like an article suggestion or a product listing. This makes them really effective because they don’t scream “AD!” quite as loudly.
For native ads on StackAdapt, you usually provide different components rather than one fixed size. This includes:
Images: Often, you’ll need a main image (like 1200×627 pixels for landscape, or maybe 627×627 for square). Sometimes a logo (like 200×200 or 100×100). File sizes for these usually follow similar rules as regular image ads, around 150KB.
Headlines: These are short bits of text, usually under 25, 50, or 90 characters. You’ll need a few options so StackAdapt can pick the best fit.
Descriptions: Longer text, maybe 90, 140, or 200 characters. Again, give a few options.
Brand Name: Just your company name.
Call to Action (CTA): This is the button text, like “Learn More,” “Shop Now,” “Download.”
URL: Where people go when they click.
What’s cool about native is how flexible it is. StackAdapt basically takes these pieces and puts them together to fit whatever layout the publisher has. So you don’t worry about 300×250, you worry about good images and compelling text. It’s more about the content itself fitting in, which I think is a pretty smart way to do things.
Video and Audio Ads (When They’re Display-Adjacent)
While we’re talking display, sometimes video creeps in. Outstream video, for example, often pops up in content feeds or between paragraphs on a webpage. So, it kinda looks like a display ad at first but then plays a video.
For video, you’re usually looking at MP4 format, maybe MOV. File sizes are much bigger, obviously. A 15 or 30-second video could be anything from 5MB to 20MB, depending on the quality. There are also specific aspect ratios (like 16:9 for landscape, 9:16 for portrait, or 1:1 for square). Bitrate and resolution matter a lot too, to make sure it looks clear but still loads reasonably fast.
Audio ads aren’t really a display thing, but some display ads might have audio components if they’re rich media. If an ad has sound, it usually needs to start muted and only play if someone clicks it. That’s just good etiquette. No one wants an ad blasting sound unexpectedly. That’s probably one of the quickest ways to annoy someone, actually.
General Stuff to Remember (Because StackAdapt Can Be Picky)
Okay, so we’ve gone over the common types. But beyond the actual numbers and formats, there are some other things that can really mess up your ad campaign if you don’t pay attention.
First, fallbacks. For HTML5 ads, you should always, always, always include a static image fallback. If for some reason the HTML5 ad can’t load (maybe someone’s browser is super old, or their connection is bad), the static image will show instead. It’s like having a backup plan, which is just sensible.
Then there’s the landing page URL. Make sure it’s correct, working, and points to exactly where you want people to go. And it needs to be an HTTPs link. In 2025, anything not secure just looks sketchy.
Ad review process: Every ad you upload to StackAdapt (or any ad platform, really) goes through a review process. They check for all sorts of things: if it meets the specs, if it contains forbidden content (like misleading claims or certain regulated products), and if it’s generally appropriate. If your ad gets rejected, don’t freak out. They usually tell you why, and you just gotta fix it and resubmit. Sometimes it’s something silly like a text size too small to read, or an image that’s just slightly over the file size limit. I’ve seen it happen.
Also, think about user experience. Even if your ad meets every single spec, if it’s annoying, people will just ignore it or even block it. So, no blinking text from the 90s, no super-fast animations that give people headaches. Keep the file sizes as low as possible without losing quality, because slow-loading ads are a drag. It’s like waiting for a really big video game to load – annoying.
And one more thing, it’s pretty crucial to test your ads. StackAdapt has preview tools, but it’s a good idea to actually see how they look on different devices if you can. What looks great on your giant desktop monitor might look squished or unreadable on a tiny phone screen.
Wrapping Up: It’s All About Being Prepared
So, yeah, StackAdapt display ad specs can seem like a lot of numbers and rules. But if you think about it, they’re just guidelines to make sure your ads look good and work right for everyone seeing them. It’s basically about making sure your message actually gets across effectively, without any technical hiccups. Being prepared with all the right sizes and formats before you even start building your campaign will save you a ton of headaches down the road. It really makes the whole process smoother, and who doesn’t like a smooth process?
In my experience, campaigns that nail the specs from the beginning tend to perform better because their ads aren’t constantly getting rejected or looking weird on different sites. And what’s interesting is that while the exact numbers for file sizes or animation lengths might tweak a bit year to year, the types of ads and the need for multiple sizes and good quality always stays the same. So getting a handle on this stuff now is a pretty smart move for anyone doing digital ads.
FAQs About StackAdapt Display Ad Specs in 2025
Sometimes it’s easier to just get quick answers, so here are a few common questions I hear about this stuff:
What are the most important image ad sizes for StackAdapt?
The absolute must-haves for image ads on StackAdapt are usually 300×250 (Medium Rectangle), 728×90 (Leaderboard), and 160×600 (Wide Skyscraper) for desktop. For mobile, 320×50 and 320×100 are pretty standard. Having these covers most of your bases and gets your ads into a lot of different spots.
What’s the general file size limit for image ads on StackAdapt?
For static image ads, you’re typically looking at a maximum file size of 150KB per image. For HTML5 ads, the initial load is often around 200KB-300KB, with polite load rules for additional assets after that. It’s a pretty tight limit, so good compression without losing quality is key.
Do HTML5 ads need a fallback image on StackAdapt?
Yes, absolutely. It’s super important to include a static image fallback (like a JPEG or PNG) in your HTML5 zip file. This ensures that if the HTML5 ad can’t load or display for any reason, a basic image will show up instead, so your ad still has a chance to be seen.
How long can animations be in HTML5 ads on StackAdapt?
Most ad exchanges, including those that StackAdapt works with, recommend keeping HTML5 animation lengths to under 30 seconds. Also, looping is often limited to just a few times, maybe two or three loops max, to prevent the ad from being too distracting or annoying for users.
What makes native ads different in terms of specs on StackAdapt?
Unlike traditional display ads that require specific pixel dimensions, native ads on StackAdapt need separate components: specific image sizes (like a landscape and a square option), various lengths of headlines and descriptions, your brand name, and a call to action. StackAdapt then takes these pieces and fits them into the publisher’s site design automatically.
