For the LinkedIn feed, export square at 1080x1080 or vertical 4:5 at 1080x1350, keep it under 30 seconds, and burn the captions in. Autoplay is muted, so an ad that needs sound to make its point makes no point at all. Those three decisions matter more than any other spec on the page, and the fourth thing to plan for is frequency, because B2B audiences are small enough that a modest budget produces consumer scale repetition within days.
The spec table for LinkedIn feed video
| Item | What to export | Why |
|---|---|---|
| Primary ratio | 1:1 at 1080x1080 | Safest single export. Renders predictably on desktop and mobile feed |
| Higher share of screen | 4:5 at 1080x1350 | Takes more vertical space on mobile, which is where most impressions land |
| Wide | 16:9 at 1920x1080 | Only if the asset is genuinely horizontal, such as a webinar clip or a wide screen capture |
| 9:16 full vertical | Avoid for feed | It is a Reels and TikTok ratio, not a LinkedIn feed ratio |
| Length | 15 to 30 seconds for prospecting | Enough for one claim and one next step, short enough to finish |
| Captions | Burned into the file | Muted autoplay. Platform auto captions are not reliable enough to bet the claim on |
| Frame rate and resolution | 1080p, 25 or 30fps, constant | Avoids the softness that comes from platform re-encoding of odd formats |
| Safe area | Keep text out of the bottom fifth | Interface chrome and the caption line sit there |
| Thumbnail | Set it deliberately | Some placements and slow connections show a still first |
LinkedIn publishes its own current file size, length and codec limits in its help pages, and they change, so check them before a big export batch rather than trusting a blog post from last year, this one included. The ratio and caption decisions above are the ones that will not change, because they follow from how the feed renders.
Every one of those ratios comes out of Genyad's LinkedIn video ad maker at 1080p with no watermark, one credit per variation. What we do not do is publish to LinkedIn for you: you export the file and upload it in Campaign Manager.
Captions are not optional
Muted autoplay means the caption is the ad. Treat the text as the primary channel and the audio as an enhancement for the minority who unmute.
What we do on every B2B video:
- Burn captions into the file rather than relying on the platform's auto captioning or an uploaded SRT. If the copy is a quantified claim, it cannot be at the mercy of a transcription error.
- Set them large. Two to three lines, high contrast, plain sans, centred or lower third but above the interface.
- Put the claim on screen as a static line in the first frame, independent of the spoken track. The viewer who reads one line and scrolls on should still have received the message.
- Keep the caption in the language of the audience, natively written rather than machine translated, because B2B copy translated word for word reads as foreign in a way a consumer voiceover does not.
Our captions and text overlays generate per variation, so a new script gets a new caption set rather than the previous one nudged around, and every language we support is written natively rather than translated.
How long should a LinkedIn video ad be?
Fifteen to thirty seconds for prospecting, and shorter than you think inside that band. The reasoning is not attention span, it is that a feed ad has one job: land one claim with a number in it, and offer one next step. Anything past 30 seconds is a landing page asset that ended up in a feed.
Where longer cuts do work:
- Retargeting a warm audience that has already had the claim: 45 to 90 seconds of demo or customer detail earns its length.
- Sponsored content aimed at a named account list where the viewer has some reason to care already.
- Webinar and conversation clips, where the interest is the substance rather than the pitch.
Structure for the 15 to 30 second version: name the role in the first three seconds so the wrong viewer scrolls and the right one stops, state one quantified outcome, show the thing that produces it, then one specific next step. One claim per ad. Committee buyers forward ads they can summarise in a sentence.
Frequency accumulates fast on small audiences
This is the part LinkedIn specs posts leave out, and it costs more money than any ratio decision.
Take a targeting definition that a B2B team would consider reasonably broad: 20,000 people. Now run a modest budget against it.
| Day | Spend at 150 per day | Impressions at a typical 40 CPM | Cumulative impressions | Frequency against 20,000 |
|---|---|---|---|---|
| 3 | 450 | 3,750 per day | 11,250 | 0.6 |
| 7 | 1,050 | 3,750 per day | 26,250 | 1.3 |
| 14 | 2,100 | 3,750 per day | 52,500 | 2.6 |
| 21 | 3,150 | 3,750 per day | 78,750 | 3.9 |
Those are audience wide averages, which understate the problem. Delivery is never even, so the responsive core of that audience, perhaps a third of it, is seeing the ad two to three times as often as the average row suggests. By day ten, your best segment has passed four exposures to the same creative, which our 2026 fatigue benchmark associates with a 45 percent CTR drop, and weekly frequency of 2.5 on Meta prospecting is where the decline begins at all.
The tension worth understanding: B2B SaaS is the slowest decaying vertical our benchmark report measures, at about 28 days to a 40 percent CTR decline, against 9 days for food and beverage. Per exposure, your creative lasts longer. But a 20,000 person audience delivers those exposures far faster than a consumer audience of millions does, so the calendar advantage disappears. Slow decay per exposure, fast accumulation of exposures.
What follows operationally:
- Plan three to four creative variations per campaign before launch, not after performance drops.
- Check frequency weekly, not CPA weekly. Frequency moves first.
- Rotate the opening rather than the whole asset. Same customer, three different opening claims, is the cheapest runway you can buy.
- Resist broadening the audience as the fix. A wider audience buys you a couple of weeks and dilutes the targeting that made the campaign work. More creative is the better lever.
Frequently asked questions
What size should a LinkedIn video ad be?
Square at 1080x1080 is the safest single export for the feed, and 4:5 at 1080x1350 takes more screen on mobile, which is where most impressions land. Use 16:9 at 1920x1080 only when the source is genuinely horizontal, and skip full 9:16 vertical, which belongs to Reels and TikTok rather than the LinkedIn feed.
Do LinkedIn video ads need captions?
Yes. Autoplay is muted, so the majority of your impressions are read rather than heard, and an uncaptioned ad delivers nothing to them. Burn the captions into the file instead of relying on automatic captioning, especially when the ad turns on a specific number.
How long can a LinkedIn video ad be?
The platform allows far longer than you should use, and 15 to 30 seconds is the working range for feed prospecting. Save 45 to 90 second cuts for retargeting warm audiences, where the viewer has already accepted the premise and wants the detail.
How many creative variations do I need for a LinkedIn campaign?
Three to four ready at launch for a normal audience, and more if you are targeting under 20,000 people. Small audiences accumulate frequency in days, so the constraint is your creative supply rather than your budget. Our benchmark report puts a typical active campaign at 8 to 20 live variations in rotation.