Guide to Social Media Best Practices

Social Media Image Sizes & Character Limits - Handles, Profile Names, Bios

Your social media presence is more than just posting pretty pictures! The difference between a crisp, engaging visual and one that’s poorly cropped or pixelated can affect everything from user trust to engagement rates. And while every social platform is different, there's one rule that holds across the board: details matter. 

From character counts to image dimensions, these updated social media best practices are your complete resource for designing content that performs across Facebook, Instagram, X, LinkedIn, YouTube, TikTok, and Bluesky.

These social media best practices will help you make sure every visual element and every line of text looks exactly the way it should.

Facebook

Despite being one of the oldest social platforms, Facebook continues to be essential for brands, especially for community-building, advertising, and event marketing. The platform’s structure allows for rich, social media content like images, links, and longform posts. But it also demands precision in how these assets are presented. Your graphics and posts must scale seamlessly between mobile and desktop, while still reflecting a consistent, professional image.

Image Guidelines

Profile Picture
Your profile image is one of the first impressions users get, so make it count. Upload a square image at 320x320 pixels, even though it’s displayed as a circle. This helps ensure that no important elements get cut off. PNGs are ideal here, especially for logos or text-based graphics.

Displays at:

• 176x176 px on desktop
• 196x196 px on smartphones
• 36x36 px on older phones

Cover Image
Whether it's your personal page, business page, event, or group, Facebook has specific dimensions for each. Use the right one to avoid awkward cropping or compression:

• Profiles & Pages: 851x315 px
• Groups: 1640x856 px
• Events: 1920x1005 px

Keep your design centered and avoid placing vital elements on the left-hand side, which will be partially obscured by your profile picture on desktop. File types should be PNG or JPG (PNG preferred).

Post Images
For consistent quality across posts:

• Square: 1080x1080 px
• Vertical: 1080x1350 px
• Max file size: 8MB

Link Previews

• Image Size: 1200x630 px

Character Limits

While Facebook allows enormous amounts of text, you’re typically competing for attention in the first few seconds of scroll. The key is to balance your freedom with user habits: short, engaging hooks followed by expandable content work best.

• Username: 5–50 characters (letters, numbers, and periods only)
• Page Description: 255 characters
• Posts: Up to 63,206 characters
• Comments: Up to 8,000 characters

Facebook usernames can’t include domain extensions (like .com), so keep them brand-specific and clean.

Instagram & Threads

With over 1.6 million active users, Instagram is still the go-to social platform for visual storytelling, and its new sibling, Threads, offers a space to stretch your brand’s voice. With shared infrastructure, these platforms offer a seamless experience across images and profiles. What sets them apart is their demand for high-quality visuals and concise, compelling copy. Consistency here isn’t just about aesthetics but credibility.

Image Guidelines

Profile Picture
Upload a square image at 320x320 pixels, optimized for circular display. For best results, keep logos or important details away from the edges.

Displays at:

• 110x110 px on mobile
• 180x180 px on desktop

Carousel Posts

• Standard Size: 1080x1350 px (4:5 ratio)
• Grid View: 1012x1350 px (3:4 ratio)
• Pro Tip: Keep focal content centered (edges often get cropped in grid views).

Reels

• Dimensions: 1080x1920 px (9:16 ratio)
• Grid Preview: 1080x1440 px (3:4)
• Centered visuals, like text, may be cut off near the edges in previews.

Stories

• Image size: 1080x1920 px
• Safe area: 1080x1610 px
• Any branding or CTAs should stay within the vertical center for mobile clarity.

Character Limits

Instagram and Threads keep things short and sharp. While there’s room to elaborate in captions, the real goal is to frontload value and invite engagement.

• Username: 1–30 characters (letters, numbers, underscores, and periods)
• Profile Name: 64 characters
• Bio: 150 characters
• Captions: 2,200 characters

Since Threads shares your Instagram handle, keeping it brand-aligned ensures continuity across your social footprint.

X (FKA Twitter)

X continues to change from short thoughts to long threads, rich visuals to expanded subscriptions. If you’re using it to build brand tone or provide fast support, staying within its media guidelines ensures that your content appears polished and professional at every scroll.

Image Guidelines

Profile Picture
Set this to 400x400 pixels to ensure it looks great at all sizes. Regular users will see it as a circle, while Verified Organizations (gold badge) use a square format. PNG is ideal here for logos and clean visuals.

Header Image

• Size: 1500x500 px
• Recommended file type: PNG or JPG

Post Images

• Vertical: 1080x1350 px
• Horizontal: 1600x900 px

Link Previews

• Image Size: 1200x630 px

Character Limits

X now offers extended text features, but that doesn’t mean all users want to read a novel. Structure matters. Break up long content, use line breaks, and include links, mentions, or CTAs early on. Get tweeting, today!

• Username: 4–15 characters (letters, numbers, underscores only)
• Display Name: Up to 50 characters
• Bio: 160 characters
• Post Length:
  • Free accounts: 280 characters
  • Premium+: Up to 25,000 characters

LinkedIn

LinkedIn social media marketing has developed far beyond a digital resume - it’s now a platform for thought leadership, B2B marketing, brand storytelling, and talent acquisition. Because it’s a professional space, every element of your presence, from your profile image to your company’s banner, needs to communicate clarity and credibility. Misaligned visuals or text-heavy images can undercut even the most compelling brand message.

Image Guidelines

Profile Picture
Your headshot or logo should be sharp and clean. A 400x400 pixel image works best. This displays as a circle, so center your focal point and avoid tight cropping.

• Max file size:
  • Personal: 8MB
  • Company Pages: 3MB
• Supported file types: JPG or PNG

Cover Image
Think of this as your brand’s elevator pitch in visual form. Use it to promote values, products, or a key campaign.

• Personal: 1584x396 px
• Company Page: 1128x191 px
• Aspect Ratio: 4:1

Post Images

• Vertical: 1080x1350 px
• Horizontal: 1080x360 px
• Max file size: 5MB

Images with a 3:1 to 4:5 ratio are safest. Anything outside of that range may be auto-cropped by LinkedIn.

Link Previews

• Image Size: 1200x627 px

Character Limits

LinkedIn gives you more space than most platforms, but that doesn’t mean you should use it all at once. Concise, clear language that delivers immediate value performs best, especially in headlines and intros.

• Company Page Name: 100 characters
• Custom URL: 3–100 characters (no special symbols or the word “LinkedIn”)
• Tagline: 120 characters
• About/Summary: 2,000 characters
• Post Captions: 3,000 characters

This is one of the few platforms where longer-form content like case studies and thought leadership can thrive; just make sure it’s skimmable and strategically formatted.

YouTube

YouTube is more than a video hosting site - it’s a brand experience platform! From someone landing on your channel from a video recommendation or a direct search, your visuals play a huge role in establishing trust and encouraging subscriptions. Your profile picture, channel banner, and video thumbnails all contribute to how people perceive your brand’s polish and professionalism.

Image Guidelines

Profile Picture
Upload a square 800x800 pixel image. YouTube will crop it into a circle, so leave generous padding around logos or faces.

• Displayed at: 98x98 px
• Max file size: 15MB
• File format: JPG, PNG

Channel Banner

• Recommended Size: 2560x1440 px (16:9 ratio)
• Safe Area (where text/logos won’t get cut off): 1546x423 px
• Max file size: 6MB

Because the banner displays differently on TVs, tablets, desktops, and phones, keep your core branding centered in that safe zone.

Video Thumbnails

• Size: 1280x720 px
• Max file size: 2MB
• Ratio: 16:9

Thumbnails are one of the most important factors in video performance. Use bold titles, contrasting colors, and focused imagery to stand out.

Character Limits

From channel metadata to video descriptions, YouTube provides plenty of space, but clarity is still king. Write for humans first, search algorithms second.

• Handle: 3–30 characters (alphanumeric, hyphens, underscores, periods)
• Video Title: Up to 100 characters
• Video Description: 5,000 characters
• Channel Description: 1,000 characters
• Comments: 10,000 characters

Optimizing these areas with keywords helps with discoverability, but user engagement often hinges on clear, useful, and compelling text.

TikTok

TikTok's rise shows no signs of slowing, and for brands, it’s a social platform where authenticity, creativity, and vertical-friendly content rule. What makes content thrive here isn't just trend participation but clean visuals that work within TikTok’s format boundaries and mobile-first design.

Image Guidelines

Profile Picture

• Recommended: 200x200 px
• Minimum: 20x20 px

Your profile image is displayed small, so focus on bold, simple imagery. Detailed logos or small type may not be legible on mobile.

Carousel Images

• Vertical (9:16): 1080x1920 px
• Vertical (4:5): 1080x1350 px

Stories & Video Thumbnails

• Image Size: 1080x1920 px

Use the 9:16 format across the board for consistency across reels, lives, and stories.

Character Limits

TikTok balances short-form spontaneity with extended caption space for context or keywords. If you’re promoting content, it’s important to maximize the first few lines before the "...more" cut-off.

• Username: 1–24 characters
• Bio: 80 characters
• Captions: Up to 4,000 characters
• Comments: 150 characters

Keep captions clear and compelling; the right line can hook users as effectively as the visual itself.

Bluesky

Bluesky is still growing its audience, but it’s gaining traction among tech-savvy and privacy-conscious users. While it mirrors a Twitter-like experience, it has its own design considerations, especially when it comes to visuals and post structure.

Image Guidelines

Profile Picture

• Recommended: 400x400 px (square, displayed as a circle)
• Max file size: 2MB

Cover Photo

• Size: 1500x500 px (3:1 ratio)
• Max file size: 2MB

Post Images

• Square: 1080x1080 px
• Landscape: 1200x627 px
• Portrait: 627x1200 px

Link Previews

• Image Size: 1200x630 px

These images should be high-res but not overly complex, since Bluesky’s minimalist design calls for clarity over flair.

Character Limits

With a focus on shorter posts, Bluesky is a platform built for quick takes and straightforward content, perfect for sparking conversation without overloading users.

• Handles: Up to 18 characters
• Profile Name: 64 characters
• Post Text: 300 characters

Given its brevity and formatting, Bluesky content benefits from clarity, wit, or bold opinion, perfect for repurposing concise ideas from longer content on other platforms.

Let ZGM Optimize Your Social Media Efforts

Trying to stay ahead of every platform’s specs, design rules, and changing algorithms? That’s a full-time job, and it's exactly the kind of challenge Zero Gravity Marketing is built for.

From high-converting visuals to strategic copywriting, ZGM helps brands grow across every major social channel. Our team stays up-to-date on the latest changes, tests what works, and turns insights into action—so you can focus on your business while we focus on performance.

Ready to get more from your social media efforts? Contact us at ZGM to start optimizing your digital presence across every channel.