Most "ad spec" lists are scattered, half out of date, and copied from each other. This one is built from the platforms' own 2026 documentation and double-checked spec by spec, by a team that uploads these creatives every day. Bookmark it, send it to your designers, and stop guessing whether 728×90 still matters (it does) or whether your HTML5 ZIP can be 5 MB on Google (it can't).
The master cheat sheet
One table, every platform. Detailed breakdowns follow below.
| Platform | Most-used sizes / ratios | Max weight | Formats | Animation |
|---|---|---|---|---|
| Google Ads — Display (uploaded) | 300×250, 728×90, 160×600, 300×600, 320×50, 320×100, 970×250 | 150 KB static 600 KB HTML5 ZIP | JPG, PNG, GIF, HTML5 | ≤30s, must stop, <5 fps |
| Google — Responsive / Demand Gen | 1200×628 (1.91:1), 1200×1200 (1:1), 960×1200 (4:5), 1080×1920 (9:16) | 5 MB per image | JPG, PNG | Static images |
| DV360 / CM360 (programmatic) | All IAB sizes — 300×250, 728×90, 300×600, 160×600, 970×250… | ~150 KB initial → 5 MB total (polite load) backup img <40 KB | HTML5 ZIP (≤100 files), JPG, PNG, GIF | ≤30s, must stop |
| Meta — Facebook & Instagram | 1080×1080 (1:1), 1080×1350 (4:5), 1080×1920 (9:16), 1200×628 (1.91:1) | Images 30 MB Video 4 GB | JPG, PNG, MP4, MOV | Video, by placement |
| TikTok | 1080×1920 (9:16) video; carousel images 2–35 | Video 500 MB | MP4, MOV, JPG, PNG | 9–30s recommended |
| 1200×628, 1200×1200, 720×900 (image) | Image 5 MB Video 500 MB | JPG, PNG, GIF, MP4 | Video 3s–30 min | |
| Microsoft Advertising | 300×250, 728×90, 300×600, 160×600, 320×50 + responsive 1200×628 | ~150 KB static responsive assets 5 MB | JPG, PNG, GIF, HTML5 | Responsive image assets are static |
| Amazon Ads | 300×250, 160×600, 300×600, 728×90, 970×250 | 60–150 KB by placement DSP 40 KB static / 200 KB HTML | HTML5, JPG, PNG, GIF | By placement |
Figures verified against each platform's official 2026 specifications. Social character limits and a handful of placement rules change frequently — always confirm those in the live ad manager before a flight.
The one rule that travels everywhere: 150 KB initial load
If you remember nothing else, remember this. The single most enforced limit across the open web is the 150 KB initial load for a fixed-size display ad. Google's Display Network caps a static image at 150 KB outright. Ad servers like Campaign Manager 360 and DV360 will accept a much heavier upload, but they serve it politely: roughly 150 KB downloads before the page is interactive, then the rest streams in afterward — up to a hard 5 MB total on DV360.
Underneath that sits the IAB's LEAN "k-weight" standard, which scales the budget to the ad's pixel area rather than using one flat number:
| Ad pixel area | Example sizes | Initial load | Polite / sub load |
|---|---|---|---|
| Under 180k px | 320×50, 300×50 | 50 KB | 100 KB |
| 180k–300k px | 728×90, 320×100 | 100 KB | 200 KB |
| 300k–500k px | 300×250, 160×600, 970×90 | 150 KB | 300 KB |
| 700k–900k px | 300×600, 970×250 | 250 KB | 500 KB |
| 1M+ px | Full-page / interstitial | 350 KB | 700 KB |
Google Ads — Display & Demand Gen
Google is still the centre of gravity for display. There are two distinct worlds here: uploaded fixed-size ads (the classic banners) and asset-based responsive ads (Responsive Display and Demand Gen), where you provide images and text and Google assembles the layouts.
Uploaded display ads (fixed sizes)
The full supported set is 20 sizes: 200×200 250×250 250×360 300×250 336×280 240×400 580×400 120×600 160×600 300×600 300×1050 468×60 728×90 930×180 970×90 970×250 980×120 300×50 320×50 320×100.
Responsive Display & Demand Gen (asset-based)
Here you supply high-resolution assets and Google fits them to every placement. Images can be up to 5 MB each. The core assets:
- Landscape (1.91:1) — 1200×628 recommended (min 600×314)
- Square (1:1) — 1200×1200 / 600×600 (min 300×300)
- Portrait (4:5) — 960×1200 — now required for Demand Gen
- Vertical (9:16) — 1080×1920 — added in early 2025 for full-screen YouTube Shorts
- Logos — square 1:1 (1200×1200) and landscape 4:1 (1200×300)
DV360, Campaign Manager 360 & programmatic
Programmatic is where file-weight gets misunderstood, because three different limits are in play at once. State which one you mean:
- Upload ceiling (what the platform accepts on ingest): CM360 / DV360 take an HTML5 ZIP up to ~9.5–10 MB and up to 100 files. This is not what gets served.
- Initial load (the practical limit): ~150 KB loads first; CM360 auto-swaps a polite-load image once total weight crosses 150 KB.
- Served total: DV360 enforces a hard 5 MB total via polite/sub-loading. Many exchange placements cap the initial ZIP at ~200–300 KB regardless.
- Backup image: a static GIF/JPG/PNG under 40 KB, matched to the ad's dimensions.
DV360 and CM360 accept the full IAB size set (300×250, 728×90, 300×600, 160×600, 970×250 and the rest). The HTML5 bundle is a ZIP of up to 100 files (HTML, JS, CSS, images, fonts) — no nested ZIPs, no localStorage/sessionStorage, and on GDN inventory no external script calls. Every clickthrough must route through the platform's click macro (clickTag / the Enabler exit), never a hard-coded URL.
Social: Meta, TikTok & LinkedIn
Social is a different universe. Forget banner pixels — these platforms want full-resolution single assets at fixed aspect ratios, and they re-crop for each placement. Build at 1080px on the short edge and you're safe.
Meta — Facebook & Instagram
| Placement | Ratio | Resolution |
|---|---|---|
| Feed (square) | 1:1 | 1080×1080 |
| Feed (vertical — recommended) | 4:5 | 1080×1350 |
| Stories & Reels | 9:16 | 1080×1920 |
| Feed / right column (landscape) | 1.91:1 | 1200×628 |
Images up to 30 MB, video up to 4 GB (MP4 or MOV). Video length depends on placement — Stories cards are short, Feed and Reels allow much longer, but 15–30 seconds performs best. The old "20% text in image" rule was retired years ago, so text overlays no longer cost you reach.
TikTok
In-feed video is the workhorse: vertical 9:16, minimum ~5 seconds, with 9–30 seconds the recommended performance window. Carousel (photo) ads take 2–35 images. Sound-on and native-feel beat polished broadcast cuts on this platform.
| Format | Sizes | Max weight |
|---|---|---|
| Single image ad | 1200×628 (landscape), 1200×1200 (square), 720×900 (4:5) | 5 MB (JPG/PNG/GIF) |
| Video ad | 1:1, 4:5, 9:16 or 16:9 | 500 MB (MP4), 3s–30 min |
Microsoft Advertising & Amazon Ads
Two platforms worth a banner set if you run cross-channel — and the good news is both reuse the standard IAB display sizes, so your Google set largely drops straight in.
Microsoft Advertising (Bing)
Standard display banners (300×250, 728×90, 300×600, 160×600, 320×50) behave like Google's, commonly capped around 150 KB for static creative. Microsoft's Audience & Multimedia responsive ads take image assets up to 5 MB at 1.91:1 (1200×628), 1:1 and a 4:1 logo — but note these responsive image assets are static only; animated GIFs are not supported there.
Amazon Ads
Amazon's weight caps are tighter and placement-specific:
- Sponsored Display / eCommerce: 100 KB for 300×250, 336×280, 160×600, 300×600; 60 KB for 728×90 and mobile; 150 KB for 970×250.
- Amazon DSP standard media: 40 KB static / 200 KB HTML per unit.
- Custom images: 1200×1200 (1:1), 1200×628 (1.91:1), 900×1600 (9:16).
- Video (Sponsored Brands / Display): up to 500 MB, 1280×720 / 1920×1080.
The IAB standard sizes — what to prioritise
Across every open-web platform above, the same handful of IAB sizes win the overwhelming majority of inventory. 300×250 alone is roughly 40% of Google Display impressions. If you build these, in this order, you have effective full coverage:
- 300×250 — Medium Rectangle (the single most important size)
- 728×90 — Leaderboard
- 160×600 — Wide Skyscraper
- 300×600 — Half-Page (high viewability, premium CPMs)
- 320×50 — Mobile Leaderboard
- 320×100 — Large Mobile Banner
- 970×250 — Billboard
- 336×280 — Large Rectangle
Add 250×250, 200×200, 120×600 and 468×60 if you want the long tail, and 970×90 / 300×1050 for high-impact desktop. That's the whole open-web playbook.
Build one master banner, get all the sizes back
Our free in-browser tool reflows a single static banner into the full IAB size set — no upload, no signup. Or hand the whole set to our team and get platform-ready, spec-compliant HTML5 banners in 24–48 hours.
Frequently asked questions
What is the maximum file size for a banner ad?
It depends on the platform and creative type. The most common hard limits are 150 KB for a static image ad on the Google Display Network and 600 KB for an HTML5 ZIP on Google Ads. Ad servers such as Campaign Manager 360 and DV360 accept much larger uploads but serve "politely" — roughly 150 KB loads first, then the rest, up to a 5 MB total on DV360. Building to a 150 KB initial load keeps a creative safe almost everywhere.
What are the most common banner ad sizes in 2026?
The five sizes that win the most inventory are 300×250 (medium rectangle), 728×90 (leaderboard), 160×600 (wide skyscraper), 320×50 (mobile leaderboard) and 300×600 (half-page). 300×250 alone is around 40% of Google Display impressions. Adding 320×100, 970×250, 336×280 and 250×250 covers the vast majority of placements.
How long can a banner ad animation be?
On Google Ads, the Google Display Network and most ad servers, animation must be 30 seconds or shorter and must stop after 30 seconds — looping is allowed but it has to come to rest. Animated GIF frame rate must be slower than 5 frames per second. Many publishers enforce a stricter 15-second limit, so 15 seconds is the safest target for maximum reach.
Can I reuse one banner set across Google, Meta, DV360 and the rest?
Static display sizes (300×250, 728×90 and so on) carry across Google Ads, DV360, Microsoft and Amazon with only minor file-weight differences. Social platforms (Meta, TikTok, LinkedIn) are a separate system — they use aspect ratios (1:1, 4:5, 9:16) and high-resolution single assets such as 1080×1080 and 1080×1920, not fixed banner pixels. One display set covers the open web; social needs its own ratio-based set.
What is the difference between initial load and polite (sub) load?
Initial load is the file weight that downloads before the page is interactive, kept small (around 150 KB) so the ad never slows the page. Polite or sub load is the remaining weight that downloads after the page finishes rendering — extra images, frames and fonts. The IAB LEAN k-weight standard sets both per ad size; a 300×250, for example, allows about 150 KB initial and 300 KB subload.
Do Meta and TikTok use banner sizes like 300×250?
No. Meta, TikTok and LinkedIn build around aspect ratios and full-resolution creative, not IAB banner pixels. For feeds use 1:1 (1080×1080) or 4:5 (1080×1350); for Stories, Reels and TikTok use 9:16 (1080×1920). LinkedIn single-image ads run 1200×628 (landscape) or 1200×1200 (square).