Image dimensions (Desktop):
728x90*, 300x250*, 160x600* (standard sizes)
120x600, 300x600
Image dimensions (Mobile):
320x50*, 300x50* (smartphone banner, most common)
320x480*, 480x320 (smartphone interstitial)
300x250* (mobile interstitial, tablet in-app, mobile web)
728x90* (tablet only)
1024x768*, 768x1024 (tablet interstitial)
File size (KB):
-200 KB max for each image.
-Bulk upload in ZIP files that are up to 10 MB.
File type:
-JPG, GIF, PNG, HTML5
Animation length:
No more than 15 seconds and/or 3 loops
Border:
Creative must clearly separated from the site content, either by a clear border or a non-white background color.
*Recommended Ad Sizes
File formats: MP3, OGG, M4A, MP4, AAC
Length:15 seconds, 30 seconds, or 60 seconds
Max file upload size: 100 MB
Note: Video files must include audio. If your video file does not have any audio, you will not be able to upload it.
Video dimensions: Minimum height of 144 px
-Up to 1920x1080. Avoid uploading UHD (4K) video or higher resolution.
Aspect ratio: 16:9 or 4:3
Max file upload size: 100 MB
These specifications represent ads that can spend on almost all supply sources. To achieve optimal results, provide multiple ads that meet the characteristics of specific exchanges and publishers. However, if you only have one ad or set of ads, follow these specifications:
Headline: 20 characters (however, 25 characters is accepted on almost all inventory)
Body: 90 characters
Main Image: Exactly 1200x627 (1.91:1 aspect ratio)
Icon/Logo: Exactly 240x240 (1:1 aspect ratio)
Brand Name: 25 characters
Note: These specs are the lowest common denominator usable on Basis DSP's current supply sources. Native ads vary greatly by publisher and exchange; for best results, produce ads to the specifications of each publisher or exchange.
If you are designing and developing your custom display ads, be sure they meet the following specifications:
These ad units allow advertisers to fill every space on the Google Display Network. This includes Native, Text, and Banner ad spaces. They do this by being responsive to the space and showing one of many text and visual combinations available. That will affect the way our ads appear:
Impressions are higher as Google is increasingly preferring to use Responsive Ads to fill inventory, but on top of that, CTR for these Responsive Ads is higher than both other ad units
Image
Logo
Limitations
Recommended image size: 1200 x 628 pixels.
Minimum width and height: 600 pixels.
Recommended aspect ratio is between 9:16 to 16:9, but crops to 1.91:1 with a link.
Recommended image formats are JPG and PNG.
Images with 20% text or more could increase chances of failed delivery.
Recommended to upload the highest resolution video possible.
Recommended aspect ratios (Horizontal: 16:9, Square: 1:1, Vertical: 4:5 or 2:3 and Full Portrait: 9:16).
Minimum dimensions 600 x 315 (1.9:1 landscape) or 600 x 600 (square).
Recommended video formats are .MP4 and .MOV (see full list here).
Max video file size is 4GB.
Recommended image size: 1080 x 1920 (but keep any text within 1080 x 1420)
Image ratio: 1.91 to 9:16.
Images no more than 20% text
Minimum resolution for Stories ads: 600 x 1067 pixels.
Recommended image size: at least 1080 x 1080 pixels
Minimum width and height of 600 pixels (minimum 254 x 133 pixels for Messenger Home Carousel Ads).
Minimum 2 cards and max of 10 cards per Carousel Ad.
Recommended ratio is 1:1.
Max image size of 30MB.
Images with 20% text or more could increase chances of failed delivery.
Here's an Always Up-To-Date List of Facebook Ad Sizes & Specs