LinkedIn video specs in 2026: length, file size, captions and who can post

LinkedIn takes MP4 videos between 3 seconds and 30 minutes long and between 75 KB and 500 MB in size when they are posted through its API. It doesn't restrict the aspect ratio, so the same vertical 1080×1920 file you use for Reels works; a square or landscape version often reads better in a desktop feed.

LinkedIn video requirements

One detail in LinkedIn's documentation can confuse developers: the specification section says 500 MB, while the upload request field accepts files up to 5 GB. The larger number covers other video uses such as ads; for an organic feed post, plan on 500 MB.

Which aspect ratio works best on LinkedIn

LinkedIn plays whatever you upload, so the choice is about the viewer, not the API. Most LinkedIn reading happens in a feed where a vertical video takes up a lot of space on a phone and is shown smaller on a desktop. Two practical options:

• Reuse the vertical master (1080×1920) when the same clip goes to Reels, TikTok and Shorts. It's the least work and plays correctly.

• Export a square (1080×1080) or 4:5 version when LinkedIn is a main channel and your audience is mostly on desktop.

Either way, keep the file in MP4 — LinkedIn's API accepts no other container. The export settings that fit every network are in our social media video specs overview.

Captions and thumbnails

LinkedIn lets you attach one caption file to a video, and only English captions are supported. For a feed post the video is still published if caption processing fails; for an ad, the caption must process successfully. If you post in another language, burn the subtitles into the video instead — many people watch the feed with the sound off.

A custom thumbnail is optional. Without one, LinkedIn may generate its own from the video, so the same rule as on Instagram applies: if your first seconds are a fade or a logo animation, upload a thumbnail.

Profile or company page: who can post

LinkedIn separates posting as a person from posting as an organization:

The two are separate permissions on LinkedIn's side, and not every scheduling tool has the organization one. Check before you plan a page calendar around a tool. Uplonic currently connects personal LinkedIn profiles.

Post text

LinkedIn's Posts API doesn't publish a maximum length for the post text in its documentation; a text that is too long is rejected with a "field length too long" error. Hashtags written as #keyword in the text are recognised, and mentions of people or companies need the exact name to link. Keep the first two lines strong — that is what shows before "see more". How the limits compare across networks is in social media character limits.

For developers: LinkedIn's API versions expire

Every call to LinkedIn's REST API carries a version header (for example Linkedin-Version: 202609). LinkedIn supports each monthly version for at least a year; after that, calls with the old header return an error. An integration that worked last year can stop posting without any change on your side. Updating the header to a current version is LinkedIn's documented migration path — and worth a yearly calendar reminder.

Before you schedule a LinkedIn video

• MP4, between 3 seconds and 30 minutes, under 500 MB.

• Vertical master, or a square/4:5 version for desktop-heavy audiences.

• Subtitles burned in if you don't post in English.

• A thumbnail if the video starts with a fade or logo.

• The right account: profile or company page.

Our video spec checker tests length, size and format in your browser.