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Posting guide

Social media image sizes, specs, and posting best practices for 2026

Every image size, video spec, and character limit for LinkedIn, X, Facebook, Instagram, TikTok, YouTube, and Bluesky on one page, with the posting habits that get your posts found in search and quoted by AI assistants.

Last checked by Radi8. Platforms change these, so we re-check them.

Quick answer: the sizes that work everywhere

Feed image 1080 × 1350 px (4:5, portrait). It takes up the most room in the feed on LinkedIn, Facebook, Instagram, X, and Bluesky.
Square image 1080 × 1080 px (1:1). The one size that works everywhere without cropping.
Vertical video 1080 × 1920 px (9:16) for Reels, TikTok, YouTube Shorts, and Stories.
Landscape video 1920 × 1080 px (16:9) for YouTube and for LinkedIn video meant for desktop.
Link preview image 1200 × 630 px (1.91:1). Set it on your own site as the og:image.
Profile photo At least 400 × 400 px, square, with your face in the middle. Most platforms crop it to a circle.

Social media image sizes and limits, all platforms at a glance

Platform Feed image Vertical Link preview Post text Video length
LinkedIn 1080 × 1350 (4:5) 1080 × 1920 video (9:16) 1200 × 627 3,000 characters Up to 15 min (desktop)
X (Twitter) 1600 × 900 (16:9) or 1080 × 1350 (4:5) 1080 × 1920 video (9:16) 1200 × 630 280 characters (25,000 with Premium) 2 min 20 s (longer with Premium)
Facebook 1080 × 1350 (4:5) 1080 × 1920 (9:16) 1200 × 630 63,206 characters Reels; no fixed limit in the app
Instagram 1080 × 1350 (4:5) or 1080 × 1440 (3:4) 1080 × 1920 (9:16) No clickable links in posts 2,200 characters, 5 hashtags Reels: 3 min safe everywhere
TikTok 1080 × 1920 (9:16) 1080 × 1920 (9:16) No clickable links in posts 4,000 characters in the app 10 min in the app, 60 min uploaded
YouTube Thumbnail 1280 × 720 (16:9) Shorts 1080 × 1920 (9:16) Uses your thumbnail Title 100, description 5,000 15 min (12 hours verified); Shorts 3 min
Bluesky 1080 × 1350 (4:5) or 1080 × 1080 (1:1) Video up to 10 min (9:16 or 16:9) 1200 × 627 300 characters 10 min, 300 MB

Sizes are in pixels, width × height.

LinkedIn image sizes, specs, and best practices

Personal profiles and Company Pages

Post images at 1080 × 1350 (4:5) or 1080 × 1080 (1:1), keep the point of the post in its first two lines, and remember a post can run to 3,000 characters but most people only see the first 140 to 210 before "see more."

LinkedIn image sizes

FormatSize (px)Aspect ratio
Profile photo400 × 4001:1
Profile background1584 × 3964:1
Company Page cover1128 × 191About 6:1
Post image, portrait1080 × 13504:5
Post image, square1080 × 10801:1
Post image, landscape1200 × 6271.91:1
Link preview1200 × 6271.91:1
Document (carousel) page1080 × 1350 or 1080 × 10804:5 or 1:1

LinkedIn character limits

Post3,000 characters
Shown before "see more"About 210 characters on desktop, 140 on mobile
Comment1,250 characters
Headline220 characters

LinkedIn video specs

  • MP4, 3 seconds to 15 minutes from desktop (10 minutes from the mobile app), up to 5 GB.
  • Vertical (9:16 or 4:5) fills more of the mobile feed; landscape (16:9) suits desktop viewers.
  • Documents: upload a PDF of up to 300 pages and 100 MB, and it shows as a swipeable carousel.

Posting on LinkedIn: best practices

  • Say the point in the first line. Everything after "see more" is for the people already interested.
  • Write from your own work: a client problem, what you did, what happened. Specifics travel further than advice.
  • Use portrait images or a document carousel. Both take up more of the screen than a landscape photo.
  • Use a few specific hashtags or none. They help people browsing a topic, not the post itself.
  • Reply to comments. The conversation under a post is part of the post.

X (Twitter) image sizes, specs, and best practices

Posts, threads, and profiles

Post images at 1600 × 900 (16:9) or 1080 × 1350 (4:5), up to four per post, and keep each post to one idea in 280 characters, or use a thread when it needs more.

X (Twitter) image sizes

FormatSize (px)Aspect ratio
Profile photo400 × 4001:1
Header1500 × 5003:1
Post image, landscape1600 × 90016:9
Post image, portrait1080 × 13504:5
Post image, square1080 × 10801:1
Link card1200 × 6301.91:1

X (Twitter) character limits

Post280 characters (up to 25,000 with Premium)
LinkCounts as 23 characters, however long it is
Bio160 characters
Display name50 characters

X (Twitter) video specs

  • MP4 or MOV, up to 2 minutes 20 seconds and 512 MB on a free account. Premium accounts can post longer video.
  • 1920 × 1080 (16:9), 1080 × 1920 (9:16), and 1080 × 1080 (1:1) all play natively.
  • Up to four images, or one video or GIF, per post.

Posting on X (Twitter): best practices

  • One idea per post. If it needs more room, write a thread and make the first post stand on its own.
  • Post more often here than on other networks. The feed moves fast, so a post has a short life.
  • Add alt text to every image. It helps people using screen readers and gives search something to read.
  • Reply to people in your field. On X, conversations do more for you than broadcasts.

Facebook image sizes, specs, and best practices

Pages, profiles, and groups

Post images at 1080 × 1350 (4:5) or 1080 × 1080 (1:1), video at 1080 × 1920 (9:16) since video posts now show as Reels, and keep the text short even though the limit is over 63,000 characters.

Facebook image sizes

FormatSize (px)Aspect ratio
Profile photo320 × 3201:1
Cover photo (Page or profile)851 × 3152.7:1
Group cover1640 × 8561.91:1
Post image, portrait1080 × 13504:5
Post image, square1080 × 10801:1
Post image, landscape1200 × 6301.91:1
Stories and Reels1080 × 19209:16
Link preview1200 × 6301.91:1

Facebook character limits

Post63,206 characters
Comment8,000 characters
Page description255 characters

Facebook video specs

  • Video posts show as Reels: upload 1080 × 1920 (9:16), MP4 or MOV, up to 4 GB.
  • Stories: 1080 × 1920 (9:16), up to 60 seconds each.
  • Keep the cover photo's key content in the middle. Mobile crops the sides.

Posting on Facebook: best practices

  • Keep it short. Long posts get cut off, and the first line decides whether anyone taps "See more."
  • Post photos and video natively instead of only sharing links.
  • Ask questions people actually want to answer, like a recommendation or an opinion, not "thoughts?"
  • Show up in the groups your customers are already in, especially local ones, as a person rather than an ad.

Instagram image sizes, specs, and best practices

Feed posts, carousels, Reels, and Stories

Post feed images at 1080 × 1350 (4:5), or 1080 × 1440 (3:4) to match the profile grid, Reels and Stories at 1080 × 1920 (9:16), and use up to five hashtags in a caption of up to 2,200 characters.

Instagram image sizes

FormatSize (px)Aspect ratio
Profile photo320 × 3201:1
Post image, portrait1080 × 13504:5
Post image, grid-matched1080 × 14403:4
Post image, square1080 × 10801:1
Post image, landscape1080 × 5661.91:1
CarouselUp to 20 slides, all cropped to the first slide's ratioAny of the above
Stories and Reels1080 × 19209:16
Reel cover1080 × 1920 (the grid shows the middle 3:4)9:16

Instagram character limits

Caption2,200 characters
Shown before "more"About 125 characters
HashtagsUp to 5 per post (since December 2025)
Bio150 characters
Username30 characters

Instagram video specs

  • Reels: 1080 × 1920 (9:16), MP4 or MOV. Up to 3 minutes works everywhere, including scheduling tools; the app accepts longer uploads.
  • Stories: 1080 × 1920 (9:16), up to 60 seconds per story.
  • Keep text and faces away from the top and bottom of vertical video, where the caption and buttons sit.

Posting on Instagram: best practices

  • Make the first line of the caption the hook. Only about 125 characters show before "more."
  • Use carousels to teach: one point per slide, and a first slide that says what the reader gets.
  • Pick up to five specific hashtags that describe the post. Broad ones bury it.
  • Add captions to video. Most people watch with the sound off.
  • Write alt text for images. Instagram fills it in automatically, but yours will be better.

TikTok image sizes, specs, and best practices

Videos and photo carousels

Post video and photos at 1080 × 1920 (9:16), up to 10 minutes recorded in the app or 60 minutes uploaded, and put the words people search for in your caption, on screen, and out loud.

TikTok image sizes

FormatSize (px)Aspect ratio
Profile photo200 × 200 minimum (upload larger)1:1
Video1080 × 19209:16
Photo carousel1080 × 1920, or 1080 × 1350; up to 35 photos9:16 or 4:5

TikTok character limits

Caption4,000 characters in the app (often 2,200 through scheduling tools)
Bio80 characters

TikTok video specs

  • MP4 or MOV, 1080 × 1920 (9:16).
  • Up to 10 minutes recorded in the app, up to 60 minutes uploaded.
  • Keep text out of the bottom fifth and the right edge, where the caption and buttons sit.

Posting on TikTok: best practices

  • Earn the first two seconds. Start with the result, the question, or the problem, not a greeting.
  • Talk to the camera. A person explaining something they know beats a polished montage.
  • Use the words people search for in the caption, on screen, and out loud. People search TikTok like a search engine.
  • Add on-screen captions. They help people watching on mute and tell TikTok what the video is about.

YouTube image sizes, specs, and best practices

Videos, Shorts, and channels

Upload long-form video at 1920 × 1080 (16:9) with a 1280 × 720 thumbnail, Shorts at 1080 × 1920 (9:16) up to three minutes, and write a title that says what the video answers in under 70 characters.

YouTube image sizes

FormatSize (px)Aspect ratio
Profile photo800 × 8001:1
Channel banner2560 × 1440 (keep text in the middle 1546 × 423)16:9
Video thumbnail1280 × 720, under 2 MB16:9
Video1920 × 1080 (up to 3840 × 2160 for 4K)16:9
Shorts1080 × 19209:16

YouTube character limits

Title100 characters (about 70 show in search)
Description5,000 characters (the first 150 or so show above the fold)
Tags500 characters in total

YouTube video specs

  • MP4 (H.264 video, AAC audio) at 1920 × 1080 or higher.
  • Up to 15 minutes until you verify your account, then up to 12 hours or 256 GB.
  • Shorts: up to 3 minutes, vertical (9:16) or square.

Posting on YouTube: best practices

  • Title the video with the question it answers, in the words a viewer would type.
  • Add chapters (timestamps) in the description. They show in search and let people jump to the part they need.
  • Upload or correct the captions. They make the video searchable and quotable.
  • Use Shorts to get found and long videos to go deep, and link from one to the other.

Bluesky image sizes, specs, and best practices

Posts and profiles

Post up to four images per post (up to 2 MB each) or one video up to 10 minutes, keep posts to 300 characters, and use your website's domain as your handle.

Bluesky image sizes

FormatSize (px)Aspect ratio
Avatar400 × 400 (up to 1 MB)1:1
Banner1500 × 500 (up to 1 MB)3:1
Post imageAny size up to 2 MB; 1080 × 1350 or 1080 × 1080 work wellShown at its own ratio
Link card1200 × 6271.91:1

Bluesky character limits

Post300 characters
Alt text2,000 characters
Bio256 characters
Display name64 characters

Bluesky video specs

  • One video per post, up to 10 minutes and 300 MB, MP4.
  • A post holds up to four images or one video, not both.
  • Accounts hosted by Bluesky verify their email before the first video upload.

Posting on Bluesky: best practices

  • Use your domain as your handle (you.com instead of you.bsky.social). It ties your posts to your website.
  • Write alt text. Bluesky readers expect it, and it gives search something to read.
  • Be conversational. On Bluesky, replies and threads get further than announcements.
  • Share links to your own writing. A post with a link and a sentence on why it matters fits right in.

Posting best practices for every platform

The specs get your post to look right. These habits get it found, by the people scrolling and by the search engines and AI assistants they ask.

  1. Write one idea for each channel, not one post for all of them

    The same idea can work everywhere, but a LinkedIn post, a Reel, and a Bluesky post are different things. Change the length, the opening, and the format for each one instead of pasting the same text five times.

  2. Lead with the answer

    Put the point in the first line. Feeds cut everything else off, and search engines and AI assistants pull the sentence that answers the question, so make sure there is one.

  3. Use the words your customers use

    Name the problem, the role, and the place the way a customer would type them. Public posts on LinkedIn, X, YouTube, TikTok, and other networks can show up in search, and they can only match the words that are in them.

  4. Add alt text and captions

    Alt text describes an image, captions transcribe a video. Both make your posts accessible, and both turn pictures and speech into text that search and AI can read.

  5. Keep the same name, photo, and bio everywhere

    Use one name and one photo, and say what you do the same way on every profile, linking to your website. It helps people, search engines, and AI assistants tell that all of these profiles are the same expert.

  6. Link back to a page you own

    Posts get attention; your website keeps it. Point the posts that matter at an article or page on your site, so the depth lives somewhere you control and that can be cited.

  7. Post at a pace you can keep

    Consistency beats volume. Two good posts a week, every week, build more than a burst of ten and then a month of nothing. If you keep falling off, fix the system, not your willpower.

Questions about social media sizes and posting

What is the best image size for social media in 2026?

1080 × 1350 pixels (4:5, portrait) for feed posts. It takes up the most room in the feed on LinkedIn, Facebook, Instagram, X, and Bluesky. If you need one image for every platform, use 1080 × 1080 (1:1), which no platform crops.

What size should social media video be?

1080 × 1920 pixels (9:16, vertical) for Instagram Reels, TikTok, YouTube Shorts, Facebook Reels, and Stories. Use 1920 × 1080 (16:9, landscape) for long-form YouTube video and for LinkedIn video meant for desktop.

What are the character limits on each platform?

LinkedIn posts allow 3,000 characters, X allows 280 (25,000 with Premium), Facebook 63,206, Instagram captions 2,200, TikTok captions 4,000 in the app, YouTube titles 100 and descriptions 5,000, and Bluesky 300. On most platforms only the first 125 to 210 characters show before the post is cut off.

How many hashtags should I use?

A few specific ones, or none. Instagram allows up to 5 per post as of December 2025. On LinkedIn, X, and Bluesky, two or three that describe the post are plenty. Broad hashtags put your post in a pile; specific ones put it in front of people looking for that topic.

What happens if I upload an image at the wrong size?

The platform crops it, adds bars around it, or compresses it. Text near the edges gets cut off and small text turns blurry. Upload at the recommended size and keep important text and faces away from the edges.

Do social media posts help SEO and show up in AI answers?

They can. Public posts and videos on LinkedIn, X, YouTube, TikTok, and other networks can show up in search results, and AI assistants draw on what they can find. Posting consistently on a clear subject, under the same name everywhere, with links back to your own site, gives them more to find and connect to you.

How often do these specs change?

A few times a year. Platforms add formats, change limits, and adjust how images are cropped. We checked every number on this page in November 2026 and update it when the platforms change.

One idea, the right version for every channel.

Radi8 takes one idea and writes a version for each channel you use, in your voice and at the right length, records video vertical or landscape with the teleprompter, and schedules it all. Free for 30 days with 100,000 AI credits, no credit card.

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