Ideal file sizes, formats, and media limits for social media posts

Check SocialBu media limits, supported formats, caption limits, video durations, and platform-specific requirements before publishing.

Written By Ghina Rehman

Last updated 7 days ago

Each social media platform has its own requirements for file size, format, media count, caption length, video duration, and dimensions. Use this guide to prepare your images, videos, and documents before scheduling or publishing through SocialBu.

Note: These limits are based on SocialBu's current publishing validation and connected platform API rules. Platform APIs can change, and some account-specific limits may vary.

General Media Limits

  • Maximum image size: 15 MB

  • Maximum video size: 953 MB

Facebook

Note: Facebook videos can be posted as Reels or Stories from SocialBu. Video publishing is still subject to Facebook's API processing and account limits.

  • Media count: 80 images or 1 video

  • Caption/text limit: 5,000 characters

  • Supported formats: JPG, PNG, BMP, TIFF, JPEG, MP4, M4V, MOV, QT, AVI, WEBP

  • Video duration: 1 second to 2 hours

  • Minimum video width: 120px

X/Twitter

  • Media count: 4 images or 1 video

  • Caption/text limit: 280 characters by default. Some premium account types may support longer text in SocialBu.

  • Supported formats: JPG, PNG, GIF, JPEG, MP4, M4V, MOV, QT, AVI, WEBP

  • Video duration: 1 to 140 seconds by default. Some premium account types may support longer videos.

  • Minimum video dimensions: 32x32px

  • Thread replies: Up to 50 threaded replies can be added.

Instagram

Note: Instagram requires media. SocialBu also checks Instagram's publishing quota, which is 25 posts per 24-hour window.

  • Media count: 10 images or 1 video

  • Caption/text limit: 2,000 characters

  • Supported formats: JPG, PNG, JPEG, MP4, M4V, MOV, QT, AVI, WEBP

  • Video duration: 3 seconds to 15 minutes

  • Minimum video width: 480px

  • Stories: Story videos are limited to 60 seconds.

  • Trial Reels: Trial Reels require a single video and at least 100 followers.

LinkedIn

  • Media count: 20 images or 1 video

  • Caption/text limit: 3,000 characters

  • Supported formats: JPG, PNG, JPEG, GIF, MP4, QT, M4V, MOV, WEBP, PPT, PPTX, PDF, DOC, DOCX

  • Video duration: 3 seconds to 10 minutes

  • Video size limit: Up to 5 GB

  • Video dimensions: Minimum 256x144px, maximum 4096x2304px

  • Documents: A document title is required when publishing PDF, DOC, DOCX, PPT, or PPTX files.

Google Business Profile

  • Media count: 1 image

  • Caption/text limit: 1,500 characters

  • Supported formats: JPG, PNG, JPEG, WEBP

  • Image dimensions: Minimum 250x250px, maximum 10000x10000px

Mastodon

  • Media count: 4 images or 1 video

  • Caption/text limit: 500 characters

  • Supported formats: JPG, PNG, JPEG, GIF, MP4, QT, M4V, MOV, WEBP

  • Video duration: 1 to 140 seconds

  • Thread replies: Up to 10 threaded replies can be added.

YouTube

  • Media count: 1 video

  • Description/text limit: 5,000 characters

  • Supported formats: MP4, M4V, MOV, QT, AVI

  • Video duration: 3 seconds to 12 hours

  • Video dimensions: Minimum 360x360px, maximum 4096x4096px

  • Shorts: Videos marked as Shorts are processed in vertical format.

Reddit/Subreddit

  • Media count: 1 image or 1 video

  • Post content limit: 10,000 characters

  • Title limit: 300 characters

  • Supported formats: JPEG, PNG, JPG, GIF, MP4, MOV

  • Video duration: 3 seconds to 15 minutes

  • Video dimensions: Minimum 360x360px, maximum 4096x4096px

TikTok

Note: TikTok requires media. Available privacy options and maximum video duration can vary by account and are fetched from TikTok creator information when available.

  • Media count: 35 images or 1 video

  • Caption/text limit: 2,200 characters

  • Title limit: 90 characters

  • Supported formats: JPG, PNG, JPEG, MP4, M4V, MOV, QT, AVI, WEBP

  • Video duration: 3 seconds to 10 minutes by default

  • Video dimensions: Minimum 360x360px, maximum 4096x4096px

  • Frame rate: 23 FPS or higher

Pinterest

  • Media count: 1 image or 1 video

  • Caption/text limit: 500 characters

  • Supported formats: JPG, PNG, JPEG, MP4, QT, M4V, MOV, WEBP

  • Video duration: 1 second to 5 minutes

  • Minimum video dimensions: 100x100px

  • Video pins: A thumbnail is required for video pins.

Bluesky

  • Media count: 4 images or 1 video

  • Caption/text limit: 300 characters

  • Supported formats: JPG, PNG, GIF, JPEG, WEBP, MP4, M4V, MOV, QT, AVI

  • Video duration: 1 to 180 seconds

  • Minimum video dimensions: 32x32px

  • Alt text: Media alt text can be up to 2,000 characters.

  • Thread replies: Up to 10 threaded replies can be added.

Threads

  • Media count: 10 images or 1 video

  • Caption/text limit: 500 characters

  • Supported formats: JPG, PNG, JPEG, MP4, M4V, MOV, QT, AVI, WEBP

  • Video duration: 1 second to 5 minutes

  • Minimum video dimensions: 32x32px

  • Thread replies: Up to 10 threaded replies can be added.

Need Help?

If you have questions about a rejected file, unsupported format, or media upload issue, contact us at support@socialbu.com. Our support team will be happy to help.