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Last updated: 2026/5/29

Postable content

Supported Social Platforms
X (Twitter)InstagramThreadsFacebook
Supported Plans
FreePersonalProfessionalBusinessEnterprise

This document explains the types of content that can be posted on each social media platform, along with image and video file formats and size limitations.

Posts in formats other than those specified may result in errors. Even if images and videos are created in the specified formats and sizes, the social media platform may convert or compress them, which could lead to a reduction in quality.

All Social Media Platforms​

Text​

  • Emojis are supported.

X (Twitter)​

Text​

  • Posts up to 140 characters
  • Long-form posts over 140 characters
    • Japanese: Up to 12,500 characters
    • English: Up to 25,000 characters
    • Available only to X Premium (formerly Twitter Blue) subscribers.

Images​

  • Format: JPG, PNG, GIF, WebP, BMP
    • If a WebP image larger than 5MB is uploaded, it will be converted to JPEG format when compressed by SocialDog.
    • BMP images will be converted to JPEG format.
  • Size: Up to 5MB (per image)
    • If the browser supports image compression, images exceeding this size will be automatically compressed to a postable size.
  • Up to 4 images

Animated GIFs​

  • Format: GIF
  • Size: Up to 15MB
  • Resolution: 1280x1080 or less
  • Frame count: 350 or less
  • Pixels (product of height, width, and frame count): Up to 300 million

Videos​

  • Size: Up to 512MB

The recommended video formats published by X (Twitter) are as follows:

Recommendations​

  • Recommended Video Codec: H264 High Profile
  • Recommended Frame Rate: 30FPS, 60FPS
  • Recommended Video Resolution: 1280x720 (landscape), 720x1280 (portrait), 720x720 (square)
  • Recommended Minimum Video Bitrate: 5,000kbps
  • Recommended Minimum Audio Bitrate: 128kbps
  • Recommended Audio Codec: AAC LC
  • Recommended Aspect Ratio: 16:9 (landscape or portrait), 1:1 (square)

Advanced Processing​

  • Frame Rate: 60FPS or less
  • Size: 32x32 to 1280x1024
  • File Size: 512MB or less
  • Playback Duration: 0.5 seconds to 140 seconds
  • Aspect Ratio: 1:3 to 3:1
  • Pixel Aspect Ratio must be 1:1
  • Supports YUV 4:2:0 pixel format only
  • Audio
  • Do not include Open GOP.
  • Always use progressive scan.

Threads (Tree Format)​

Polls (Surveys)​

Poll duration can also be set.

Accounts that can Reply​

The following settings are available:

  • Everyone
  • Accounts you follow
  • Verified accounts
  • Accounts you @-posted

Daily Post Limit​

  • Verified Accounts (X Premium subscribers): 2,400 posts
  • Unverified Accounts: 50 standard posts / 200 replies

Unsupported Content​

  • Bold/Italic text
  • Post-submission editing

Instagram​

On Instagram, the formats for images and videos that can be posted differ between Feed/Reels posts and Stories posts.

Feed & Reels​

If one video is attached, it will be posted as a Reel.

Text​

  • Up to 2,200 characters
    • For Reels: Up to 733 characters for Japanese.

Images​

  • Format: JPEG, PNG, WebP, BMP
    • If an image in a format other than JPEG is uploaded, it will be converted to JPEG format.
  • Size: Up to 8MB
    • Images exceeding this size cannot be uploaded.
    • SocialDog does not compress images intended for Instagram posts.
  • Aspect Ratio: Ranging from 4:5 to 1.91:1
  • Up to 10 images

Videos​

  • Format: MP4, MOV, QuickTime
  • Size: Up to 300MB
  • Video Length:
    • Feed: 3 to 90 seconds
    • Reels: 3 seconds to 15 minutes
  • Aspect Ratio: 4:5 to 16:9
  • Audio: 1 or 2 channels (mono or stereo)

Stories​

Mentions​

Images​

  • Format: JPEG, PNG
    • If an image in a format other than JPEG is uploaded, it will be converted to JPEG format.
  • Size: Up to 8MB
    • Images exceeding this size cannot be uploaded.
    • SocialDog does not compress images intended for Instagram posts.
  • Aspect Ratio: 9:16 (recommended)
    • If media with an aspect ratio different from the recommended 9:16 is posted, Instagram may add padding or crop portions of the media.

Videos​

  • Format: MP4, MOV
  • Size: Up to 100MB
  • Video Length: 3 to 60 seconds
  • Aspect Ratio: 9:16 (recommended)
    • If media with an aspect ratio different from the recommended 9:16 is posted, Instagram may add padding or crop portions of the media.
  • Audio: AAC, up to 2 channels

Unsupported Content​

  • Stories/Reels
    • Adding music
    • Adding text
    • Adding stickers (Polls, Questions, Emojis, Links, Hashtags, Mentions, Location)
    • Simultaneous posting to multiple SNS accounts
  • Reels
    • Specifying cover (thumbnail)

Daily Post Limit​

100 posts

Facebook​

Text​

  • Up to 60,000 characters

Images​

  • Format: JPEG, PNG, WebP, BMP, TIFF
    • WebP images will be converted to JPEG format.
    • If a BMP image larger than 4MB is uploaded, it will be converted to JPEG format when compressed by SocialDog.
  • Size: Up to 4MB (PNG up to 1MB)
    • If the browser supports image compression, images exceeding this size will be automatically compressed to a postable size. However, TIFF images cannot be compressed.
  • Up to 10 images

Videos​

  • Size: Up to 100MB
  • Format: MP4, MOV, GIF
  • Aspect Ratio: Ranging from 9:16 to 16:9

Threads​

Text​

  • Posts up to 500 characters are possible.

Images​

  • Format: JPEG, PNG
  • Size: Up to 8MB (per image)
  • Number of images that can be attached per post: Up to 20 images
  • Aspect Ratio: Ranging from 0.01:1 to 10:1
  • Color space: sRGB (If the image uses another color space, it will be converted to sRGB.)

Videos​

  • Format: MOV or MP4
  • Size: Up to 1GB
  • Length: Up to 300 seconds
  • Audio: AAC, maximum sample rate 48 kHz, 1 or 2 channels (mono or stereo)
  • Video Codec: HEVC or H264

Daily Post Limit​

250 posts