Google Display Ad Sizes: The Complete 2026 Guide

Google Display Network (GDN) reaches over 35 million websites, apps, and Google-owned properties — more than 90% of global internet users. Your image ads compete for placements across all of them. Get the dimensions wrong and your creative won't serve. Get them right and you have one less thing standing between your campaign and results.

This is the full spec sheet: every supported size, file requirements, responsive display ad asset rules, top performers, and the rejection reasons that eat creative budgets.

Master Table: All Google Display Network Ad Sizes

Google supports two types of uploaded image ads: standard fixed-dimension banners and the newer flexible sizes. The table below covers every supported fixed dimension.

Need to resize your ad creative to any of these dimensions?

File Requirements for Uploaded Image Ads

Google has strict file requirements for uploaded image ads. Violate any of these and the ad is rejected before it ever serves.

Format and Size Limits

150 KB is a hard limit, not a target. A 300×250 JPG at that limit still needs to render fast — compress to around 80–100 KB for real-world performance. Use Pixotter's compressor to hit the target without a visible quality hit.

If you're working with PNG files that come in oversized, converting to JPG saves significant file size for photographic creative. See JPG vs PNG for when each format makes sense. You can convert between formats directly in your browser.

Safe Zone Rules

• Keep all text and logos within a safe margin of at least 5% from each edge
• Avoid placing critical content in the bottom 20% — many placements crop or overlay this area
• Don't include simulated browser chrome, fake close buttons, or misleading UI elements (instant rejection)

The Four Top-Performing GDN Sizes

Google's own data consistently shows four sizes generating the majority of impressions across the Display Network. If you're building a lean creative set, start here.

300 × 250 — Medium Rectangle

The workhorse of display advertising. It fits in more placements than any other size — sidebars, content pages, in-article, and mobile web. When publishers add a single ad slot, it's almost always 300×250. If you ship one creative, ship this one.

Design note: Horizontal layouts work best. Keep headline above the fold (top 60% of the unit). CTA button should be large enough to tap on mobile.

336 × 280 — Large Rectangle

Same shape as the 300×250, roughly 12% larger. It gets fewer total placements but commands more attention when it appears. Good second unit to produce — reuse most of your 300×250 layout with minor adjustments.

728 × 90 — Leaderboard

Horizontal banner that lives at the top of pages, above the main content. High visibility, low engagement rate compared to rectangles — it's seen but not always acted on. Works best for brand awareness and retargeting (where you just need the logo seen repeatedly).

Design note: Text-heavy layouts work well here given the wide canvas. Keep font sizes readable — minimum 14px for body copy in a 728×90.

300 × 600 — Half Page

The premium unit. It's half a page tall and commands serious attention. CPMs are higher than rectangles, but click-through rates are also higher. Publishers limit how many of these they run per page, so inventory is tighter — but when it serves, it performs.

Design note: You have vertical space — use it for a visual story: problem → solution → CTA. Don't just stretch a 300×250 layout.

Mobile-Specific Sizes

Mobile traffic accounts for more than 60% of GDN impressions. These sizes are specifically optimized for mobile placements.

320 × 100 vs 320 × 50: The large mobile banner has nearly double the click-through rate of the standard mobile banner in most campaigns. The size difference in creative production effort is minimal. Produce the large version unless you have a specific reason not to.

For a broader look at ad sizes across platforms, see our banner ad sizes reference.

Responsive Display Ads

Responsive display ads (RDAs) are Google's preferred format. Instead of uploading a fixed-dimension image, you supply the raw assets and Google assembles the ad automatically for each placement. More placements, less creative production time — at the cost of some design control.

Asset Requirements

Image file size: Max 5 MB per asset for responsive display ads (more lenient than uploaded image ads).

Text Asset Limits

Supply the maximum number of assets. Google's algorithm tests combinations and learns which perform best. Five headlines and five descriptions give it 25 possible combinations versus just one if you supply minimums.

For details on preparing square images for ads and other placements, see our image size for website guide.

Video Ad Dimensions

Google Display Network also runs video ads. These follow YouTube's spec since GDN video ads are served through YouTube's infrastructure.

Accepted video formats: MP4 (H.264), MOV, AVI, WMV, FLV, MPEG-4, WebM. MP4/H.264 is the safest choice — it's accepted everywhere and produces the best quality-to-file-size ratio.

Design Best Practices by Size

Rectangle Units (300×250, 336×280)

• Layout: Visual asset left or top, copy and CTA right or bottom
• Headline: Maximum 4 words; make them count
• CTA button: Minimum 80×30px; high-contrast color (not the same hue as the background)
• Logo: Top-left corner, max 20% of total ad height
• White space: Don't fill every pixel — breathing room increases readability

Leaderboard (728×90)

• Left-to-right scan pattern: Brand/logo → value proposition → CTA
• Minimum font size: 14px for any readable text
• Avoid vertical text: The narrow height makes it unreadable
• Animation: If using GIF, animate the CTA — not the background

Half Page (300×600)

• Narrative structure: Use the vertical space to tell a story
• Two CTAs: One at mid-unit, one at bottom — both linking to the same URL
• Image quality: At 300×600, image quality is visible — compress to target size without degrading quality. See how to compress images to 200KB for the process.

Mobile Banners (320×50, 320×100)

• Text must be legible at arm's length: Minimum 12px, but 16px is better
• CTA takes up 30–40% of the unit width
• No fine detail: At 50px height, a complex image is noise

Aspect Ratio Reference

If you're working from a master creative and need to export multiple sizes, understanding the underlying aspect ratios saves significant time. Many GDN sizes share ratios.

For a deeper look at ratios and how to calculate them for any format, see our image aspect ratio calculator guide.

Common Rejection Reasons

Google's policy review catches these automatically. Fix them before submitting.

Borderless ads are a common gotcha. If your creative has a white or light-colored background, Google requires a visible border so it's distinguishable from the page content. A 1px medium-gray border solves it.

Preparing Images for GDN

Most designers deliver creative at 2× for retina displays, then scale down. Here's the practical workflow:

1. Design at 2× (e.g., 600×500 for a 300×250 unit)
2. Export as JPG at 85% quality
3. Scale to target dimensions in a tool like Pixotter's resizer
4. Check file size — if over 100 KB, compress further
5. Verify rendered dimensions match the spec exactly

For social media campaigns running alongside GDN, the size requirements are completely different. See our social media image sizes guide for the full breakdown across platforms.

FAQ

What is the most effective Google Display ad size? 300×250 (medium rectangle) consistently achieves the highest impression volume because it fits the most placements. For raw performance (click-through rate), 300×600 typically outperforms when inventory is available. Build both if budget allows — 300×250 for reach, 300×600 for premium placements.

What file formats does Google Display Network accept for image ads? JPG, PNG, and GIF for uploaded image ads. Google formally retired SWF/Flash support in 2024. For responsive display ads, the same formats apply plus a 5 MB size limit (versus 150 KB for uploaded image ads).

Can I use the same creative for all sizes? You can — but you'll get mediocre results across the board. The 728×90 leaderboard and the 300×600 half page have fundamentally different layouts. The better approach: design a master layout, then adapt it properly for each aspect ratio group rather than stretching or cropping the same file.

What's the maximum file size for Google Display ads? 150 KB for uploaded image ads. Responsive display ad image assets allow up to 5 MB, but smaller files load faster and perform better — aim for under 500 KB even when the limit is higher.

Should I use responsive display ads or uploaded image ads? Responsive display ads for scale — they reach more placements and require less creative production work. Uploaded image ads for precision — when you need exact visual control over what serves. In practice, run both: RDA as your primary campaign type, a handful of uploaded sizes (300×250, 300×600, 728×90) for placements where you want full control.

How do I resize an image to Google Display ad dimensions? Use a browser-based tool like Pixotter's image resizer — enter the target width and height, and it outputs the exact pixel dimensions without server upload. Then run the result through the compressor to hit the 150 KB limit.

What's the difference between GDN and YouTube ads? GDN ads appear on third-party websites and apps in the Google Display Network. YouTube ads appear on YouTube specifically. Both are managed through Google Ads, but they use different creative formats — GDN supports static image and GIF banners; YouTube focuses on video formats (skippable, non-skippable, bumper). The 300×250 rectangle can appear adjacent to YouTube videos, which is a GDN placement on the YouTube domain.

Do Google Display ads support animated images? Yes — GIF animation is supported for uploaded image ads with two constraints: the animation must stop after 30 seconds, and it can loop a maximum of 3 times. HTML5 animated ads are not supported for uploaded image ads; for animated HTML5 you need Google Web Designer and the HTML5 format, which runs through Display & Video 360.