Which number applies to what

LinkedIn video specs, and which of them apply to an organic post

Most LinkedIn video specs you will find are advertising specifications. The widely quoted set — three seconds to thirty minutes, 75 KB to 500 MB — comes from a block that introduces itself as sizing for non-connected-television video and refers the reader on to LinkedIn's Video Ads Advertising Specifications, where the same figures appear. This page separates what LinkedIn publishes for the upload itself, what it prints only in help pages that carry no version, and the one figure it does not publish at all.

What are the LinkedIn video specs for an organic post?

Start with why the usual answer is wrong, because it is wrong in a way that is easy to verify and easy to repeat.

The Videos API documentation carries a block headed “Video File Size Specifications”. It gives three seconds to thirty minutes, 75 KB to 500 MB, and MP4. Those are the numbers almost every LinkedIn video guide repeats.

The upload maximum LinkedIn does state for the API sits further down, on the required file-size field of the upload request itself. How the LinkedIn API is shaped covers where each of LinkedIn’s four video sources comes from and what each is scoped to.

What LinkedIn publishes, and what Postdom does with it

One of these is enforced. The rest are recorded with their evidence and their date, which is a different promise and is labelled as one.

Each fact with its classification, source and verification date
Fact	Value	What it means	Checked
Container format	video/mp4Enforced by Postdom	The only LinkedIn video fact Postdom enforces, and the narrowing is Postdom's own. LinkedIn's Pages page lists around fifteen accepted formats and withdraws three, saying “We no longer support AVI, QuickTime, or MOV files.” Postdom sends MP4 alone — narrower than LinkedIn requires, which can only reduce what reaches it, and that is why it is safe to enforce where a maximum from the same prose would not be.	Source · 2026-09-02
Maximum file size for the upload	5 GBRecorded, not enforced	Stated on the upload request's own required field, which makes it the strongest LinkedIn video fact available: it is the only one from a versioned source. Recorded as a recommendation rather than a gate because Postdom's own ceiling is lower and rejects first, so a check here could never fire.	Source · 2026-09-02
Maximum duration	Not publishedNot published	LinkedIn publishes no duration ceiling for organic posting through the API. Three figures circulate and each is scoped to something else. Adopting one would turn a scoped number into a general rule, which is the failure this whole page exists to describe.	Source · 2026-09-02
Smallest frame	256x144Recorded, not enforced	By longest and shortest side, not by width and height. The source bounds the frame, so a portrait video with those numbers reversed is inside the range rather than over a height limit.	Source · 2026-09-02
Largest frame	4096x2304Recorded, not enforced	From a help page titled “Video sharing troubleshooting” that carries no version and only a relative “last updated” label. Real, recorded, and not something Postdom rejects on: that provenance cannot carry a rejection.	Source · 2026-09-02
Aspect ratio range	1:2.4 to 2.4:1Recorded, not enforced	From the same unversioned page. The advertising specification uses a different model entirely, which is a second reason not to enforce this one.	Source · 2026-09-02

The file-size figure is recorded rather than enforced for a concrete reason: Postdom’s own upload ceiling is 500 MB, an order of magnitude below LinkedIn’s, so nothing Postdom accepts could ever reach it. A check there would never fire, and a guard that cannot fire is not protection.

The one LinkedIn does not publish

There is no maximum video duration for organic posting through LinkedIn’s API. Not a long one, not an unknown one — LinkedIn does not state it. What exists instead is three real figures, each belonging to something else, which is why you have probably met a confident answer already.

Three circulating figures, and what each is actually scoped to
Figure	Belongs to	Why it is repeated as general
Ten minutes	LinkedIn Pages and Career Pages	The company-page specification, not the member-profile one — which is the opposite of how it is usually repeated.
Fifteen minutes	Video sharing, split by client	From the troubleshooting page, which divides its figures by desktop and mobile rather than by surface.
Thirty minutes	Advertising	From the file-size block on the Videos API page, which introduces itself as sizing for non-connected-television video and links out to the advertising specifications, where the same figures appear.

The minimum has the same problem in miniature: the sharing page splits it by client rather than by surface, giving three seconds on desktop and two on mobile. A page that reports one number for the minimum has already chosen a device without saying so.

So Postdom records the ceiling as unpublished and does not check duration for LinkedIn. That is the honest position and it is also the useful one: a limit invented from the wrong scope would reject video LinkedIn accepts.

The Pages and ads documents themselves — file-size ranges, format withdrawal, codec, named ratios, in-stream length — are listed on LinkedIn video requirements, kept as three documents rather than folded into this organic-API table.

Why a portrait video is not over the limit

LinkedIn states its resolution range as a pair — smallest frame to largest frame. It bounds the frame, not width and height separately.

Read as a width cap and a height cap, the larger of those numbers looks like a ceiling on height, and every portrait video appears to breach it. Read as the source states it, a portrait video with those dimensions reversed is inside the range. Postdom records the pair by longest and shortest side for exactly this reason, so the stored fact cannot be misread as an axis limit later.

Both the frame range and the aspect-ratio range come from a help page titled “Video sharing troubleshooting” that carries no version and only a relative “last updated” label. They are recorded because they are real and first-party; they are not enforced because that provenance cannot carry a rejection. A stale maximum rejects video the platform would accept, and being wrong in that direction costs a customer a post.

Questions about LinkedIn video specifications

What are the LinkedIn video specs for an organic post?

LinkedIn publishes fewer of them than the internet suggests. The upload request states a maximum file size; the container format is settled by Postdom rather than by LinkedIn, which accepts around fifteen; the frame and ratio ranges exist only in an unversioned help page; and the maximum duration is not published for organic API posting at all.

Why do LinkedIn's own pages show 500MB and 5GB?

They are scoped to different things. The 500MB figure sits in a block that introduces itself as non-connected-television ads sizing and refers the reader to Video Ads Advertising Specifications. The 5GB figure is stated on the upload request's required file-size field. Neither is presented by LinkedIn as the organic feed limit, and the ads block appears higher up the page, so a reader checking the citation meets it first.

How long can a LinkedIn video be?

LinkedIn does not publish an answer for organic posting through its API. Ten minutes is the Pages specification, fifteen comes from a sharing troubleshooting page that splits its figures by desktop and mobile, and thirty is the advertising figure. Each is real and each is scoped to something other than the member-profile organic case, so this page names them rather than picking one.

Is a portrait video outside LinkedIn's resolution range?

Not by itself. The published range bounds the frame rather than width and height separately, so a portrait video whose dimensions are the reverse of the stated maximum is inside it. Reading the pair as a width cap and a height cap is what makes portrait video look non-compliant when it is not.

Which of these does Postdom actually check?

The container format, and nothing else on this page. Postdom rejects a LinkedIn video that is not the supported format before handing it over. The file-size figure is recorded rather than enforced because Postdom's own ceiling is lower and rejects first, and the frame and ratio figures are recorded with their dates because unversioned help prose cannot carry a rejection.