LinkedIn video or Reels for a founder: what each platform's docs say

15 minutes is the ceiling for a LinkedIn video post and 20 minutes is the ceiling for a reel, per LinkedIn's Video sharing troubleshooting page and Instagram's Record a reel page, both read on 25 September 2026.

Neither number matters for a founder clip.

The limits that matter are the small ones, and I found most of them the hard way.

Here is what I wish I had read before we posted a founder's clip to both platforms from a phone, in month one of a VALORAE Media engagement.

The clip had captions burned into the bottom third. On Reels it looked fine.

On LinkedIn the text sat under the interface, and when I went to attach a caption file instead, the option was not on the phone.

So I did what most people do. I deleted the post, said nothing, and started reading help pages.

Step 1: What each platform says native video does

LinkedIn's Share a video on LinkedIn FAQ, read 25 September 2026, says three things that shape everything else.

One video per post. No animated GIFs. And you cannot post directly into the immersive vertical video feed, which selects from existing videos on its own.

That last line is the one founders miss.

The vertical feed on LinkedIn is a destination you earn, and the only lever is ordinary video posts that hold attention.

Instagram's Record a reel page, read the same day, says a reel can run to 20 minutes, but reels over 3 minutes will not be recommended to new audiences.

So the honest framing is this. LinkedIn treats a video as a post with a file attached, and Instagram treats a reel as the unit of distribution, with a stated length past which it stops helping you.

I did not know if the 3-minute line was real or folklore until I read it on Meta's own page. It is on the page.

Step 2: The comparison table (limits, captions, visibility, surfaces) from the docs

Every row below comes from a platform help page read on 25 September 2026, and the page is named in the last column.

Two rows in that table cost me the deleted post.

The LinkedIn caption file is desktop only, per the Add Closed Captions page. And the Reels cover cannot be changed after upload, per the Reel size page.

Both are one-way doors, and both closed on me from a phone.

Step 3: What is worth posting to both and what only fits one

Post to both: a clean master with no burned-in text, cut under 3 minutes, in 9:16 or 4:5. Both shapes sit inside both ratio ranges above.

The one video, five platforms post covers the export.

Then caption it per platform. On LinkedIn that means desktop, with an SRT or the auto caption toggle and review switched on before it publishes.

Only fits LinkedIn: anything that leans on the written post above the video. Reels has nowhere to put that text where anyone reads it.

Only fits Reels: anything that wants strangers.

Instagram's Who can see and share your reels page lists Feed, the Reels viewer, Explore, and audio, effect and hashtag pages for a public account. LinkedIn's FAQ lists your feed, Groups and Pages, and says the vertical feed picks for itself.

Burned-in captions are lazy.

They feel efficient because one export works everywhere, and they are the exact reason my clip went under the LinkedIn interface. LinkedIn's own FAQ says to keep the top, bottom and sides of the video free of key elements, text and logos. A sidecar caption file moves with the interface, and pixels do not.

Step 4: How to pick one if you can only run one channel

Pick by who has to see it, never by which app you enjoy.

If the buyer already knows your name, LinkedIn. Its FAQ says your 1st-degree connections automatically follow your posts, so the first audience is built in, and for a founder selling to peers it is the right one.

If the buyer has never heard of you, Reels.

The trial reels post on Instagram's creators blog, dated 10 December 2024 and read 25 September 2026, says a trial reel goes to non-followers first. Views, likes, comments and shares show about 24 hours later, per that same post, and it can auto-share to followers on views within the first 72 hours.

But there is a catch. The creators blog's Tips for improving your reach post, dated 31 May 2023, says Instagram is less likely to recommend reposts or content with noticeable watermarks. So the LinkedIn export with a logo in the corner is the wrong file to send.

At VALORAE Media, when a founder can only carry one channel, this is the fork we use.

I did not know if the connection-follow rule would matter in practice. It does, because the first viewers on LinkedIn can reply with a meeting, and the first viewers on Reels mostly cannot.

Step 5: The signal that tells you to drop one, from the platform's own analytics fields

Both platforms hand you the number that decides it.

LinkedIn's View analytics for your videos page defines a video view as more than 2 seconds watched, beside watch time, average watch time, impressions and members reached. Instagram's View insights on your reels page defines views, watch time, viewers, average watch time and follows.

The shared field is average watch time.

So divide it by the clip length, per platform, for the same clip, and write both numbers down every month.

Drop the platform where that number keeps falling while the other holds. A hook can buy views, and nothing buys watch time.

Two caveats from the docs. LinkedIn says video analytics are not available for posts shared only with connections or in Groups, so post publicly or you get nothing to compare. And Instagram says reel insights need a public account and stay available for up to two years.

I run this on my own accounts, linkedin.com/in/tgsidd and instagram.com/tgsiddh, before any VALORAE Media client is asked to.

The metrics post has the rest of the sheet, and if the clips come from a podcast, founder short-form content on the Arc blog covers the cutting side.

I did not know if a founder would tolerate a spreadsheet. Most do, once the column is one number.

The short version

• Export a clean master under 3 minutes with no burned-in text.
• Caption on LinkedIn from desktop, with an SRT or auto captions and review on.
• Pick the Reels cover before upload, because it is locked after.
• Post publicly on both or you get no analytics to compare.
• Divide average watch time by clip length, per platform, every month.
• Drop the platform where that number keeps falling.

This is what we do at valoraemedia.com.