The Complete Guide to Google Display Network Ad Specs in 2025

Okay, listen — ad specs aren’t boring, they’re everything. The Google Display Network hits over 90% of internet users across 2M+ sites, videos, and apps, so getting sizes, file types, and specs right is the difference between an ad that crushes it and one that eats your budget. Whether you’re a pro or just starting, this guide walks you through the exact GDN specs, smart best practices, and optimization tricks so your display ads actually perform.

Understanding the Google Display Network

Here’s the deal: search ads show up when people are looking for something. But the Google Display Network? That’s like billboards on the internet — your ads pop up while people are watching YouTube, scrolling Gmail, playing games, or reading blogs. The magic? You don’t just spray ads everywhere. You can target by age, hobbies, behavior, or even remind someone who almost bought from you (yep, that pair of shoes that keeps following you around online). GDN isn’t just about selling stuff — it’s about getting noticed, making people curious, and nudging them closer to hitting “buy.”

Essential Image Ad Specifications

Okay, so image ads are the bread and butter of the Google Display Network. They’re eye-catching, flexible, and can sneak into just about any corner of the internet. But here’s the thing: if your ad isn’t sized right, it’s like trying to jam a square peg in a round hole — it won’t fit, and you miss out big time.

Standard Display Ad Sizes

Google gives you tons of size options, but some just crush it more than others. Think of these like the “cool kids” that get invited everywhere:

300 x 250 pixels (Medium Rectangle) – The all-star. This size gets shown the most.
336 x 280 pixels (Large Rectangle) – Perfect when you want your ad front and center, right where people actually see it.
728 x 90 pixels (Leaderboard) – The OG banner across the top of a page. Big and bold.
300 x 600 pixels (Half Page) – Tall and impossible to ignore in a sidebar.
320 x 100 pixels (Mobile Banner) – If you’re not thinking mobile, you’re missing half the game.

Other good ones to keep in your back pocket:

160 x 600 (Wide Skyscraper), 970 x 250 (Billboard), 468 x 60 (Banner), 250 x 250 (Square), and 320 x 50 (Mobile Leaderboard).

Image File Requirements

Here’s where people mess up — you can design the slickest ad ever, but if you don’t follow Google’s upload rules, it won’t even make it online.

Formats: JPG, PNG, or GIF (but nope, no moving GIFs here).
Max size: 150 KB (yep, KB, not MB — so keep it lean).
Color mode: Stick with RGB so your ad doesn’t look weird on different screens.
Animation: Forget it. Static only for standard display ads.

Image Quality Best Practices

Specs are the basics, but quality is where you level up. A sloppy ad is like showing up to prom in sweatpants.

Use crisp, high-res images (blurry = amateur hour).
Text should be short, sharp, and not cover more than 20% of your ad.
Keep your branding consistent — your ads should look like they belong to you.
Don’t cram too much in. A cluttered design = people scroll right past.
Always, always give people something to click — a bold “Shop Now” or “Learn More” goes a long way.

Responsive Display Ads Specifications

Responsive display ads are Google’s golden child right now. Why? Because they’re like a chameleon — they resize, reshape, and restyle themselves to fit wherever they land. Big box, skinny banner, mobile feed — boom, your ad looks good. That’s why if you’re running serious GDN campaigns, you need these.

Asset Requirements for Responsive Ads

This is where you load up Google with all your creative ammo. The more you give it, the more ways it can remix your ad.

Images (Landscape):

Aspect ratio: 1.91:1 (wide shot vibes)
Minimum: 600 x 314 px (bare minimum — don’t be lazy)
Recommended: 1200 x 628 px (nice and crisp)
You can upload up to 15 of these bad boys.

Images (Square):

Aspect ratio: 1:1 (think Instagram square)
Minimum: 300 x 300 px
Recommended: 1200 x 1200 px
Again, up to 15 allowed — use ‘em!

Logos:

Aspect ratio: 1:1 (square) or 4:1 (landscape)
Minimum: 128 x 128 px (square) / 512 x 128 px (landscape)
Recommended: 1200 x 1200 px (square) / 1200 x 300 px (landscape)
You can upload up to 5 logos.

Headlines & Descriptions:

Short headlines: Up to 5 (30 characters each — quick, punchy)
Long headline: Just 1, max 90 characters (room to flex a little)
Descriptions: Up to 5, max 90 characters each (tell the story, but keep it tight)
Business name: 25 characters (don’t overthink it).

Optimization Tips for Responsive Display Ads

Here’s where the magic happens — give Google’s algorithm more to play with, and it’ll find the winning combo.

Upload all the images you can — don’t be that person who only gives 3.
Mix up your headlines: funny, bold, serious, mysterious — let the machine test ‘em all.
Make sure each piece (headline, image, logo) can stand alone, because Google will shuffle them like a deck of cards.
Try different CTAs (“Shop Now,” “Learn More,” “Don’t Miss Out”) — sometimes one tiny phrase wins big.
Balance product talk with benefit talk. Don’t just say what it is, say why it matters (“Faster shoes” vs. “Run like lightning”).

HTML5 Ad Specifications

Alright, if static images are like posters and responsive ads are like Lego sets, then HTML5 ads are full-on video game levels you get to build. These give you way more creative freedom — animations, interactivity, shiny effects.

Technical Requirements

Here’s the checklist you cannot skip, or Google will straight-up reject your ad faster than you can say “reload.”

File format: Everything goes in a ZIP file (like packing your suitcase).
Max size: 150 KB (so pack light, no oversized files).
Entry point: You need an index.html file — that’s the “front door” to your ad.
Supported features: CSS3, JavaScript, SVG, WebGL (aka the nerdy magic tools that make stuff move and glow).
Click tag: Use Google’s click tag so they can track who’s actually clicking your masterpiece.
Animation: Max 30 seconds — nobody wants a forever-looping disco ball ad.
Compression: Squeeze everything down so it loads fast. No one waits for slow ads.

HTML5 Design Considerations

This is where you stop thinking like a coder and start thinking like a gamer who knows how to hook people in.

Load time optimization: Shrink your images, tidy your code. If it loads slow, people bounce.
User interaction: Add little things to click or hover over — make it feel alive.
Fallback images: Some places can’t handle HTML5 (old browsers, weird apps). Always pack a backup static image.
Mobile responsiveness: Test it on every screen you can. That “perfect” desktop ad might look broken on a phone.
Animation control: Don’t make people dizzy. Looping forever = instant annoyance. Respect the vibe.

Video Ad Specifications for GDN

Think of video ads on the Google Display Network like mini movie trailers that pop up while people scroll — they can show up off-YouTube too, so you still need to make every second count. These have rules, but follow them and your ad will play nice across sites and apps.

In-Stream Video Requirements

File format: MP4, MOV, AVI, or MPEG.
Resolution: At least 640 x 360 pixels (360p).
Aspect ratio: 16:9 (landscape mode) or 9:16 (portrait mode).
File size: Not more than 1 GB.
Length: Varying depending on the format, but 15–30 seconds is optimal for best performance.

Video Best Practices

Hook in the first 3 seconds: Treat it like a TikTok — if you don’t grab them fast, they swipe.
Brand early: Put your logo or product up front so people remember who’s talking.
Clear audio: Bad sound ruins good visuals — use decent mics or clean mixes.
Add captions: Tons of people watch with sound off; captions save you.
Strong CTA at the end: Tell viewers exactly what you want them to do next — “Shop now,” “Learn more,” whatever fits.

Google Display Network Ad Policy Requirements

Even if your ad looks amazing and fits all the specs, Google won’t let it run unless it plays by their rules. Think of it like trying to get into a club — doesn’t matter how cool your outfit is, if you don’t meet the requirements, the bouncer says “nope.”

Content Restrictions

Here’s the stuff you absolutely cannot sneak into your ads — unless you like rejection emails:

No lies or clickbait-y claims (Google hates catfishing as much as people do).
No offensive or gross material (keep it clean).
No sketchy “dangerous” products (sorry, you can’t sell fireworks or ninja stars here).
No malware or sneaky downloads (nobody wants their laptop to catch a cold).
No copyrighted stuff you don’t own (you can’t just throw Drake’s song in your ad and hope no one notices).

Landing Page Requirements

Google doesn’t just check your ad — they’ll peek at the page it leads to, too. If your landing page is shady, slow, or confusing, your ad’s toast.

Your page has to work and load fast — slow sites lose people (and Google hates that).
The content should actually match your ad. Don’t say “Free Sneakers” and send people to a blender store.
Keep navigation simple — if your page feels like a maze, users bounce.
Have clear contact info and a privacy policy — looks pro and builds trust.
No auto-downloads or annoying pop-ups that hijack the screen (instant bad vibes).

Optimizing Ad Performance Beyond Specifications

If you want your ads to actually perform (a.k.a. get clicks, conversions, and not just sit there), you’ve gotta play smarter.

A/B Testing Strategy

Testing isn’t optional — it’s how you level up.

Try out different ad sizes. Some work better in certain spots (like how a sniper rifle isn’t the move in close combat).
Swap creative styles and messages — bold vs. subtle, funny vs. serious.
Play around with calls-to-action: “Shop Now” vs. “Don’t Miss Out” — tiny changes can flip results.
Check performance on phones vs. desktops. Adjust your ads so they shine everywhere.

Audience Targeting Refinement

This is where the GDN gets scary good — you can laser-focus who sees your ads.

Use remarketing lists to follow up with people who already visited you (yep, like those sneakers that keep stalking you online).
Build “similar audiences” based on your best customers — like cloning your fanbase.
Layer demographics + interests for precision. Teens who love gaming? Parents who binge cooking shows? Boom.
Don’t waste money showing ads to people who already bought. Exclude them and chase fresh eyes.

Placement Optimization

Not every site is worth your time. Some are goldmines, others are ghost towns.

Check your placement reports — find the sites that give you the most love.
Cut off the ones with clicks but no sales (window shoppers = wasted cash).
Use managed placements if you want to handpick premium sites, like buying VIP seats instead of random tickets.
Adjust bids depending on how a site performs. High ROI spots? Pay more. Weak ones? Drop ‘em.

Conclusion

Knowing Google Display Network specs is like learning the rules of the game — it’s step one. Once you nail image ads, responsive ads, HTML5, and video requirements, your ads actually show up where they’re supposed to. But here’s the secret: specs are just the foundation. The real wins come from mixing sharp design, smart targeting, and nonstop testing. And don’t get lazy — Google’s always dropping new formats and features. Stay sharp, keep experimenting, and your ads won’t just “run”… they’ll crush it.