How to Add Attachments in a LinkedIn Post: Complete Guide

LinkedIn supports a wider range of attachment types than most people realize — documents, images, videos, polls, carousels, and native articles. Each format has different algorithm treatment, different audience engagement patterns, and different best practices for maximizing reach. Posts with optimized attachments consistently outperform text-only posts in both engagement and reach.

This guide covers every attachment type LinkedIn supports, step-by-step instructions for adding each one, format-specific best practices, and which formats work best for AI agency owners building thought leadership and generating leads.

Types of Attachments You Can Add to LinkedIn Posts

LinkedIn currently supports six types of media attachments for posts: images (single or up to nine), videos (native upload), documents (PDFs uploaded as carousel-style document posts), polls, events, and LinkedIn articles (long-form native content). Each type has different engagement characteristics and serves different strategic purposes.

For AI agency owners specifically, the three highest-value attachment formats are documents (carousel posts of frameworks, guides, and case studies), images (data visualizations, before/after comparisons, and branded graphics), and videos (screen recordings of AI demos, tutorial walkthroughs, and client result presentations). Understanding the nuances of each format before you start creating content saves significant time and produces consistently better results.

How to Add Images to a LinkedIn Post

To add an image to a LinkedIn post: click the "Start a post" button, write your post text, then click the image icon (a landscape photo icon) in the media bar at the bottom of the post editor. Select your image file — LinkedIn accepts JPG, PNG, GIF, and WEBP formats, with a maximum file size of 8MB per image. You can add up to nine images to a single post by clicking "Add more photos" after uploading the first one.

For best results, use images with a 1:1 (square) or 4:5 (portrait) aspect ratio — these take up more feed space on mobile, which is where the majority of LinkedIn traffic comes from. Images with text overlays perform well for frameworks, steps, and data points — the text gives viewers a reason to stop scrolling even if the image itself is not visually striking. Always include alt text when uploading images — it improves accessibility and may contribute to LinkedIn's content indexing.

How to Add a Document (Carousel) to a LinkedIn Post

Document posts are LinkedIn's carousel format — a PDF uploaded as a document that viewers can swipe through slide by slide. These are among the highest-performing post formats for AI agency owners because they allow you to present a multi-step framework, a case study with data, or a how-to guide in a visually engaging format that keeps viewers on the post longer.

To add a document: click "Start a post," write your post text, click the document icon in the media bar (it looks like a document page), and upload your PDF. LinkedIn converts the PDF into a swipeable carousel automatically. Maximum file size is 100MB, and LinkedIn supports PDFs up to 300 pages — though documents of three to ten slides perform best for engagement.

Design your document slides with large text and minimal content per slide — they are viewed on mobile screens at small sizes. Use consistent branding (your color scheme and logo) across all slides. Make the first slide compelling enough to earn a swipe — the first slide is what appears in the feed, and it needs to communicate enough value to make viewers want to continue. Strong first slides typically state the framework name, the number of steps, and the outcome the viewer will learn.

How to Add Video to a LinkedIn Post

To add native video: click "Start a post," write your post text, click the video camera icon in the media bar, and upload your video file. LinkedIn accepts MP4, MOV, and ASF video formats with a maximum file size of 5GB and a maximum duration of ten minutes. For most content, videos under three minutes significantly outperform longer videos on LinkedIn.

Native video — uploaded directly to LinkedIn rather than linked from YouTube — receives dramatically better algorithm treatment. LinkedIn wants users to stay on the platform, so native uploads get more distribution than external links. If you have a YouTube tutorial or demo video, upload a two to three minute highlight directly to LinkedIn rather than linking to the full YouTube video. Include captions — approximately 80% of LinkedIn video is watched without sound, so captions are not optional, they are required for the content to be understood.

How to Add a Poll to a LinkedIn Post

Polls are one of the most underused formats for AI agency lead generation. A well-crafted poll generates comments, reveals prospect pain points, and creates a natural conversation opener for follow-up outreach. To add a poll: click "Start a post," click the poll icon in the media bar, enter your question and up to four answer options, and set the poll duration (one day to two weeks).

For AI agency owners, the best poll questions are ones that reveal pain points and qualification signals in your target audience. Examples: "What is the biggest bottleneck in your lead follow-up process?" with options like response speed, qualification, scheduling, and tracking. Or "How many hours per week does your team spend on manual data entry?" with ranges as options. People who vote are signaling a pain point — follow up with those who vote for the most relevant options with a personalized outreach message.

Strategic Use of Attachments for AI Agency Owners

The most effective LinkedIn strategy for AI agency owners combines three attachment formats at different stages of the content funnel. Document carousels serve as awareness and authority content — a five-slide framework on "How we automate missed call follow-up for HVAC companies" reaches a broad audience and demonstrates expertise. Videos serve as consideration content — a two-minute demo showing an actual AI workflow in action converts curious viewers into warm prospects better than any text description. Polls serve as engagement and research content — they generate interaction from your target audience and give you qualified leads to follow up with based on their votes.

The key mistake most LinkedIn users make with attachments is treating them as visual decoration for their text post rather than as the primary content. The best attachment-heavy posts lead with the attachment — the text introduces it, provides context, and creates a reason to engage, but the attachment delivers the core value. Think of the text as the headline and the attachment as the article.

For creating document carousels efficiently, design a master template in Canva, Figma, or Google Slides with your branding, then duplicate and customize it for each post. Consistency in visual identity across your carousel posts builds recognition — after a few months of posting, your audience will instantly recognize your content style in the feed before they read the title. This brand recognition is one of the compounding benefits of consistent LinkedIn posting that most creators underestimate. For more on building a compelling LinkedIn content strategy, see our LinkedIn content pillar guide for AI agencies.