LinkedIn Guide: Formats, Documents and Best Practices
Text, images, PDF documents, video, polls and the 2026 feed overhaul: how to post on LinkedIn, with numbers verified in the official Help Center.
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LinkedIn is where a B2B brand, a firm, a school or a founder builds credibility. People don't come to be entertained; they come to learn, hire and keep up with their industry. In 2026 LinkedIn rebuilt how its feed works and said plainly what it wants to see: useful ideas, not posts engineered to farm engagement. This guide covers formats and limits verified in LinkedIn's Help Center and developer documentation, what LinkedIn says about ranking, and a practical approach for Pages and personal profiles.
Formats and limits
Text
A LinkedIn post can run up to 3,000 characters, per the Help Center. An article, LinkedIn's long-form format, can go up to 125,000 characters. In the feed, only the first lines show before "see more," so the hook does all the work.
Images
According to LinkedIn's help page on photos and videos, a post can include up to 20 photos, each up to 5 MB, with an aspect ratio between 3:1 and 4:5. Multi-photo posts display at 4:5 at most. One important detail: you can't share a link and an image in the same post. It's one or the other.
LinkedIn doesn't publish pixel dimensions for organic images. Its single image ad specs are a useful reference: 1,200 × 628 pixels horizontal (1.91:1), 1,200 × 1,200 square, and 720 × 900 for 4:5 vertical on mobile.
Documents: LinkedIn's "carousel"
On LinkedIn, what people call a carousel is really a document post: a PDF (or a PowerPoint or Word file) readers swipe through page by page. Per LinkedIn's Help Center, the file can't exceed 100 MB or 300 pages. Once published, the document can't be swapped out; only the description can be edited. Video or animation inside a document displays as a still image.
For publishing tools, the LinkedIn API documentation states that organic image carousels aren't supported. The two options are a document post or a multi-image post (2 to 20 images).
Video
Official sources differ by account type. LinkedIn's help page for Pages lists a maximum length of 10 minutes, a minimum of 3 seconds, up to 5 GB, and an aspect ratio between 1:2.4 and 2.4:1. It also says AVI, QuickTime and MOV files are no longer supported. The help page for members says 15 minutes. For a Page, plan on 10 minutes in MP4. LinkedIn also has a video feed: per its Help Center, any video you post may appear there based on relevance and performance.
Polls
Per the poll documentation, the question can be up to 140 characters and each option up to 30, with 2 to 4 options and a duration of one day, three days, one week or two weeks. A poll can't be edited once it's live.
| Format | Verified limit |
|---|---|
| Post text | 3,000 characters |
| Article | 125,000 characters |
| Images per post | Up to 20, 5 MB each, ratio 3:1 to 4:5 |
| Document (PDF, PPT, DOC) | 100 MB and 300 pages max |
| Video from a Page | 3 s to 10 min, 5 GB max, MP4 |
| Poll | 140-character question, 2 to 4 options of 30 characters |
| Link + image | Not possible in the same post |
Newsletters
A Page can run a LinkedIn newsletter. According to LinkedIn's Help Center, Pages with more than 150 followers are eligible to be evaluated for access, provided they have a history of original content and are in good standing. When the first edition goes out, the Page's followers are invited to subscribe.
What the LinkedIn feed rewards
LinkedIn's help page on feed ranking says it relies on hundreds of signals, including a post's context (helpful insights, job opportunities, career milestones), plus profile, network and activity signals. It also states that it doesn't use demographic information such as age or gender as a signal.
In March 2026 LinkedIn announced an overhaul of its feed, with ranking now driven by generative recommendation models. The announcement also covers action against comment automation, engagement pods and unauthorized third-party tools, and a reduction in repetitive, low-substance posts and engagement bait, such as "comment to agree" prompts or videos that don't match the text. On the flip side, the feed favors genuine insight, actionable ideas and thoughtful perspectives.
LinkedIn's engineering blog adds that the system now matches posts to members based on meaning, not just keywords, and weighs likes, comments, time spent on a post, and the posts people scroll past without stopping.
Bottom line: a post that holds attention because it teaches the reader something gets better treatment than one that begs for comments.
Page or profile: what goes where
- The company Page carries announcements, case studies, educational documents, job posts and the newsletter.
- Founder and team profiles carry points of view, lessons learned and behind the scenes. They extend the Page; they don't replace it.
Formats that work well for a brand: a 5- to 10-page educational document that sums up a method, a lessons-learned post built on your own data, a short video from an expert on the team, and a text post that takes a clear position on an industry topic.
Hashtags and links
LinkedIn doesn't publish official guidance on how many hashtags to use. A few specific ones at the end of a post are plenty. What matters more is that the topic is clear in the text itself, since the feed now matches posts by meaning. As for links, remember a post can't carry both a link and an image. Choose based on your goal, and put the substance in the text so the post has value even without a click.
Anatomy of a strong LinkedIn post
An effective LinkedIn post tends to follow the same shape. A first line that states the idea or result with no preamble, since that's what shows before "see more." A few short paragraphs that bring the proof: a number from your own business, a concrete example, a step in a method. A closing line that sums up the lesson in one sentence. And, where it fits, a question that invites readers to share their own experience, without asking them to "comment" for anything in return.
How often to post
LinkedIn doesn't set a recommended frequency. For a Page, a steady weekly presence tied to your news and areas of expertise beats a daily post with nothing in it, which is exactly the kind of content the 2026 overhaul aims to reduce. Replying to comments is part of publishing.
Common mistakes
- Engagement bait. "Comment YES to get the guide": LinkedIn has said explicitly that it's reducing this kind of post.
- A video that has nothing to do with the text. Also targeted by the feed overhaul.
- A 40-page document. The cap is 300 pages, but readers drop off long before that. Keep it short and dense.
- Trying to post a link and an image together. It's not possible. Pick one.
- Uploading MOV video from a Page. The format is no longer supported. Export to MP4.
- A hook buried after three lines of context. Nobody will get to it.
- Comment automation tools. LinkedIn says it's acting against them.
Pre-publish checklist
- A clear hook in the first two lines.
- Text under 3,000 characters, broken into short paragraphs.
- Image between 3:1 and 4:5, 5 MB max, or a document under 100 MB.
- MP4 video, 10 minutes max for a Page.
- A link or an image, not both.
- A useful idea, a lesson or a clear position, not a request for engagement.
- Time blocked to reply to comments.
LinkedIn without losing your evenings
LinkedIn rewards substance, and substance takes prep time. With Oposto, you describe your brand once: it learns your voice, products and audience from your website, prepares posts, design carousels and short videos suited to LinkedIn, plans them in a calendar and publishes them at the scheduled time. Then it measures real performance and reuses what works.
To see next month's LinkedIn posts ready for review, try Oposto: describe your brand once, it prepares a month of content in the right format for each network, and you approve.