Facebook

For best quality, your profile picture should be at least 320 pixels wide and 320 pixels tall.

Since your cover photo goes across the entire width of your profile, your image must be at least 720 pixels wide. If the photo you want to use is too small, try uploading the photo in high resolution.

Design Recommendations
Use these guidelines to design an ad that looks good everywhere it appears on Facebook. The recommended video and thumbnail image guidelines ensures your ad always looks high quality. The recommended text length is how many characters of ad copy could be displayed on smaller screens.
 * Text: 90 characters
 * Aspect Ratios Supported: 16:9 (full landscape) to 9:16 (full portrait)
 * Mobile in feed: Videos will be rendered as is up to 2:3, with masking to 2:3 for aspect ratios between 2:3 to 9:16
 * Desktop in feed and desktop player: For desktop in feed, vertical video will continue to be letter-boxed to 1:1. For desktop player, vertical video will be 9:16 with no black bar letter-boxing
 * Recommended Aspect Ratio for Vertical Video: 9:16 (full portrait), ensuring core content falls in the 2:3 mask for mobile News Feed
 * Video: H.264 video compression, high profile preferred, square pixels, fixed frame rate, progressive scan
 * Format: .mp4 container ideally with leading moov atom, no edit lists
 * Audio: Stereo AAC audio compression, 128kbps + preferred

Technical Requirements
Aspect Ratio: 1.77:1 / 16:9 / HDTV, 2:39:1 or 2:40:1 / Widescreen / 9:16, 1:1 / 1.33:1 / 4:3 / SDTV, 1.375:1 / film, 1.85:1 / Film, no pillar boxing or letter boxing No limit to bitrate file if you're using two pass encoding, as long as long as your file doesn't exceed 1 GB. Otherwise, 8 megabits per second for 1080p and 4 megabits per second for 720p.
 * Caption length text: Text only, max 2,200 characters
 * Recommended
 * Length: 120 minutes max
 * Minimum resolution: minimum width 600 pixels, length dependent on video aspect ratio
 * File Size: Up to 4GB max
 * Frames: 30fps max
 * Format: Full list of supported file formats here
 * Bitrate:
 * Your image should include minimal text. See how the amount of text in your ad image will impact the reach of your ad.

Slideshow Design Guidelines
Use these guidelines to design a slideshow, which is a video created from static images.
 * Recommended News Feed image size: 1,280 x 720 pixels
 * News Feed image ratio: 16:9 (max 4:3) or 1:1
 * Text: 90 characters (longer posts may be truncated on small screens)
 * Images of same size and aspect ratio are recommended to avoid cropping
 * Your image should include minimal text. See how the amount of text in your ad image will impact the reach of your ad.