LinkedIn Ad Sizes, Formats and Specs

Most LinkedIn ad size guides publish one number per format and stop. That's the recommended size, not the accepted range, and the gap between the two is where campaigns actually break. LinkedIn accepts a single image anywhere from 640 x 360 up to 7680 x 4320 pixels. The 1200 x 628 everyone quotes is a recommendation sitting inside a range roughly 144 times wider.

This guide gives you the full verified specification for each format, then the four constraints that cause most rejected or badly rendered LinkedIn ads. Every number below comes from LinkedIn's own documentation, checked on 4 August 2026.

Key takeaways

• Recommended sizes and accepted ranges are different things. LinkedIn recommends 1200 x 1200 for a square single-image ad but accepts 360 x 360 through 4320 x 4320.
• Vertical single-image ads are mobile-only. A 4:5 image won't serve on desktop, which is the most common cause of unexplained delivery gaps.
• Carousel ads don't support video, and each card headline is capped at 45 characters. That's the tightest text limit on the platform.
• The 5 MB image cap bites harder than the 500 MB video cap. A high-resolution export hits the image limit long before a 30-second video hits the video one.
• Video headlines have two numbers: 70 characters recommended, 200 maximum. The first is the truncation point, not the hard cap.

The complete LinkedIn ad size reference

Four formats carry most campaign creative. Here's what each one accepts.

Single image ads

File types are JPG, PNG, or GIF, capped at 5 MB. Text fields run to 70 characters for the headline, 150 for introductory text, and 70 for the description, which appears on the LinkedIn Audience Network only. The ad name is optional and holds 255 characters. Destination URLs accept up to 2000 characters.

Video ads

Video runs from 3 seconds to 30 minutes. Files must be MP4, between 75 KB and 500 MB, with a recommended frame rate of 30 fps. Audio needs to be AAC or MPEG4 at under 64 KHz. Headlines are 70 characters recommended and 200 maximum; introductory text is 150 recommended and 600 maximum.

Carousel ads

Carousels take 2 to 10 cards, each square at a minimum of 1080 x 1080, as JPG or PNG, with a 10 MB cap across the carousel. Card headlines hold 45 characters. Introductory text holds 255. LinkedIn's documentation is explicit that carousel ads do not support video.

Document ads

Document ads accept PDF, DOC, DOCX, PPT, and PPTX up to 100 MB. The technical maximum is 300 pages or one million words, but LinkedIn recommends staying under 10 pages. Headlines hold 70 characters and introductory text 150. Two production requirements catch people out: layered documents have to be flattened before upload, and a document whose pages aren't all the same size has to be standardized first.

Four constraints that break more campaigns than dimensions do

Dimensions are the easy part. These four rules are the ones that cause a format to serve badly, serve narrowly, or not serve at all.

Vertical single-image ads are mobile-only

LinkedIn labels every vertical single-image ratio "mobile only." If your campaign creative is 4:5 and desktop impressions look strangely thin, this is why. Square is the safest single canvas precisely because it serves everywhere without a placement caveat, which is a better reason to default to 1200 x 1200 than the usual advice about feed real estate.

Carousel headlines are capped at 45 characters

Forty-five characters is roughly six or seven words. Every other format on the platform gives you 70. Teams routinely write a carousel deck against the 70-character habit, then discover at upload that every card headline truncates. Write carousel headlines to 45 from the start and the sequence survives review intact.

The image cap is tighter than the video cap

Images cap at 5 MB. Video caps at 500 MB. That 100x difference is counterintuitive enough that it catches experienced teams: a 4320 x 4320 square PNG export will blow through 5 MB easily, while a 30-second 1080p MP4 sits comfortably under 500 MB. If a high-resolution image upload fails, compress before you resize. The dimensions are almost certainly fine.

Recommended text limits are truncation points, not caps

Video headlines list 70 characters as recommended and 200 as the maximum. Both numbers are real. The recommended figure is where LinkedIn expects the text to display cleanly; the maximum is what the field will physically accept. Writing to 200 gets your copy stored and then visually cut. Treat the recommended number as the design constraint and the maximum as an emergency ceiling.

How to build one concept across the sizes you need

The workflow that survives contact with a real campaign isn't "design once, resize everything." It's design one system, then recompose per frame.

1. Decide the message hierarchy first. One primary idea, one supporting proof, one next action. Anything beyond that won't survive the smallest frame you plan to ship.
2. Build the square master at 1200 x 1200. It serves on every placement, adapts into carousel cards without re-cropping, and gives you the most forgiving starting geometry.
3. Compose landscape separately. Move elements to use the width. A square design scaled down inside a 1200 x 628 frame reads as a mistake, because it is one.
4. Reframe video per ratio, don't letterbox. Keep captions and key objects away from the outer edges, where interface chrome and platform crops compete with them.
5. Write copy to the tightest limit in the set. If the campaign includes a carousel, 45 characters is your headline budget everywhere. Consistency across formats is worth more than four characters of extra nuance in one of them.
6. Check the live spec before final export. LinkedIn's Ads Guide is the authority for the exact placement you selected, and it changes.

Formats beyond the main four

LinkedIn's current guide lists a wider set than most size articles cover. Under Sponsored Content there are single image, video, carousel, event, document, thought leader, Connected TV, article and newsletter, and job ads. Sponsored Messaging covers conversation and message ads. Text and Dynamic Ads cover spotlight and follower ads, and Lead Gen Forms sit alongside all of them.

Two are worth knowing about specifically. Thought leader ads promote content posted by an executive, subject matter expert, or employee rather than by the company page, so the creative constraint is a real person's existing post rather than a designed asset. Connected TV ads extend a campaign into streaming inventory, which is a different production job with different specs entirely.

Preflight checklist

• The chosen ratio is supported by the placement you actually selected, and vertical single-image creative isn't expected to serve on desktop.
• Image files are under 5 MB and documents under 100 MB.
• Headlines fit the tightest limit in the campaign, which is 45 characters if a carousel is included.
• Video is MP4, at least 3 seconds, with AAC or MPEG4 audio under 64 KHz.
• Document pages are flattened and uniformly sized.
• Captions are legible in every ratio and clear of the frame edges.
• Carousel cards work individually, since nobody is guaranteed to start at card one.
• The landing page confirms whatever the ad promised.

Frequently asked questions

What is the best LinkedIn ad size?

1200 x 1200 square, for a specific reason: it's the only single-image geometry with no placement caveat attached. Landscape at 1200 x 628 works well when the source visual is genuinely wide. Vertical gives more mobile presence but won't serve on desktop.

Can LinkedIn carousel ads use video?

No. LinkedIn's carousel specification states that carousel ads do not support video. A sequence that needs motion has to run as a video ad instead.

How long can a LinkedIn video ad be?

Between 3 seconds and 30 minutes. The technical ceiling is far beyond what feed creative should use, but it makes LinkedIn viable for longer-form demo and webinar content that other platforms cut off.

What resolution should I export at?

Export at the recommended size unless you have a reason not to. Higher resolution is accepted well past the recommendation, but the 5 MB file cap arrives quickly, and LinkedIn compresses on delivery regardless.

Do LinkedIn ad specs change?

Yes, regularly. Formats get added and limits get revised. Anything you read in a guide, including this one, is a snapshot. Verify against the live spec pages before a launch that matters.

Sources and verification

Every specification above was checked against LinkedIn's public documentation on 4 August 2026. LinkedIn's live campaign setup is the final authority for the placement you select.

• LinkedIn Ads Guide
• Single image ad specifications
• Video ad specifications
• Carousel ad specifications
• Document ad specifications

Producing the set

Once the spec is settled, the work becomes volume: the same idea composed for square, landscape, and vertical, with copy rewritten to each field limit. Advibly generates creative from a website, storefront, or product asset and keeps that context available across formats, so the square and landscape versions come from one source rather than one flattened export. Every version still needs checking against the live LinkedIn spec and the placement preview.

For placements beyond LinkedIn, see the display ad size guide. For deciding what goes inside the frame, see social media content ideas, or start from the LinkedIn headline generator when the 45-character limit is the problem.