9:16 vs 4:5 video ads: choose the ratio by placement

9:16 (1080×1920) is the native format for full-screen placements: TikTok, Reels, Stories, Shorts. 4:5 (1080×1350) is the Facebook and Instagram feed format, where it takes up the maximum height allowed without going full screen. In advertising, the “9:16 vs 4:5 video” question has no single winner: you shoot a 9:16 master while protecting a central area that can be cropped to 4:5, then deliver both versions by placement. One shoot, two exports. What follows covers safe zones, the real cost of the second version and a protocol for testing the ratio without mixing up three variables. According to Médiamétrie’s L’Année Internet 2025, reported by CB News, mobile accounts for 80% of French people’s browsing time, up from 66% in 2020.

What are you really choosing when you choose a ratio?

You are not choosing an aesthetic, you are choosing ad inventory: 9:16 makes you eligible for full-screen placements, 4:5 makes you credible in the feed. And since each placement has its own cost of access, the ratio you deliver partly determines your campaign’s average CPM. It is a media-buying decision disguised as an editing question. According to Google’s internal data published in its Google Ads Help Centre (global data, 2024), adding a vertical video to a Demand Gen campaign leads to an increase of more than 35% in conversions on Shorts.

Before going further, we need to separate three things the market constantly confuses. They do not have the same cost or the same consequences.

• The shooting ratio: what the sensor sees. It can be wider or higher-resolution than what you will deliver, and that is often a good idea.
• The master ratio: the reference file, edited, colour-graded and subtitled. In principle, just one per creative.
• The delivery ratio: what the platform actually shows the user, after its own processing. You only control that one indirectly.

Confusing the three is the most expensive mistake we see in quotes. An advertiser who writes “deliverable: 1 video in 9:16” thinks they have bought a creative that can run everywhere. They have bought a master. If they then open the Feed placements, the platform crops it on its own, and nobody in the chain has approved what the crop looks like.

The link to media cost is direct. An asset limited to 9:16 does not compete in Feed inventory, which remains one of Meta’s deepest. Conversely, a 4:5-only asset cuts itself off from TikTok and Reels, where the CPMs we measure on our France campaigns in 2026 remain structurally lower than on classic social display. Restricting placements means restricting competition in the auctions, sometimes to your advantage, often not.

A ratio is not a matter of taste. It is a key to inventory, and every inventory has its price.

What is the 4:5 video format and how do you use it for marketing videos?

The 4:5 format is a vertical video whose width is 80% of its height, delivered at 1080×1350 pixels and designed to take up the maximum height allowed in the Facebook and Instagram feed. It is not a compromise between square and full screen: it is the native format of scrolling in a feed, where the interface refuses to go all the way to 9:16.

Why does Meta cap the feed at 4:5? Because a post has to leave the start of the next one visible, along with the account name, the caption and the interaction buttons. A 9:16 in a feed would push all of that off screen. 4:5 is the maximum surface an advertiser can take without breaking the reading experience.

The four cases where 4:5 beats 9:16

What we see on the accounts we manage, without turning it into a universal law:

• Audiences aged 45+ on Facebook. They consume far more feed than Reels. A budget that pushes 9:16 at this target ends up concentrated on an inventory they rarely visit.
• Wide product demos. A tabletop shot, a two-handed unboxing, a side-by-side before/after: 9:16 forces you to zoom in and cut useful information. 4:5 gives it room to breathe.
• Retargeting. Warm audiences are largely reached in the feed. Delivering 4:5 on these campaigns costs one reframe and unlocks immediate volume.
• Text-heavy creatives. Price comparison, benefits table, legal notices: 4:5 leaves more width per line, so fewer line breaks, so faster reading.

4:5 has also taken on new importance outside advertising. Since Adam Mosseri’s announcement in January 2025, the Instagram profile grid displays vertical thumbnails rather than square ones. The very concrete consequence for brands: a creative designed only for full screen has its thumbnail cropped in the grid, and a logo placed at the bottom of the image disappears. Check your last three posts before you keep reading. As RTBF reported on 21 January 2025, Instagram applied an automatic crop to photos and videos already published to move the grid from square to rectangular format.

Where is 9:16 mandatory, and what happens if you do not deliver it?

9:16 is the native format of all full-screen placements, TikTok In-Feed, Instagram and Facebook Reels, Stories, YouTube Shorts, and if you do not deliver it, the platform builds a degraded version of your creative itself. It does not reject the ad. It crops it, frames it or blurs it. And nobody tells you. Google spells this out on its help page on YouTube Shorts ad specifications: a horizontal video served in Shorts is displayed with blurred bars at the top and bottom of the vertical screen.

This is the blind spot of every format guide. They list the accepted ratios, never what the platform does with your file when it is not in the right ratio. Here is what we find when we open the placement previews, one by one, on every campaign:

• A 4:5 sent to Reels is displayed centred, with empty space or a generated background at the top and bottom. The creative loses about a third of the screen area.
• A 9:16 sent to Feed is cropped or shrunk. A hook placed at the top of the frame gets cut off, and that is precisely the zone where retention is decided in the first three seconds.
• On TikTok, the interface places the description, account name, CTA and column of buttons over your image. It is not a crop, it is an overlay, and it always eats the same zones.

Safe zones, in pixels and not in good intentions

On a 1080×1920 master, these are the margins we apply systematically in production, aligned with the safe zones published by TikTok Ads Manager and by Meta’s ads guide: about 130 px at the top, 480 to 500 px at the bottom, 150 px on the right edge, 60 px on the left. Every piece of information, whether text, price, logo or legal notice, stays inside the remaining rectangle. These values change two to three times a year: we re-check them against the official docs before every new project, and you should demand the same of your supplier. An agency still working with 2023 safe zones will deliver creatives that are half illegible.

The bottom margin is the harshest. Almost 500 px out of 1920, a quarter of the image. That is where 80% of non-specialist editors place the subtitles, out of horizontal-editing reflex. In vertical, they end up under the caption.

Which video format for social media, placement by placement?

Two masters cover 95% of social advertising needs: a 9:16 at 1080×1920 for full-screen placements, a 4:5 at 1080×1350 for feeds. 16:9 survives only on in-stream and long-form YouTube. Square no longer has a placement where it wins.

The table below is not a spec inventory. The column that matters is the fourth: what the platform does with your file when it is not in the right ratio.

Two remarks the table does not make. The first: the “ideal” durations published by the platforms do not match what we measure. On the e-commerce campaigns we produce, the paid creatives that hold up best in 9:16 run between 15 and 30 seconds, whereas the same messages in Feed only hold up at 8 to 20 seconds. The second: 16:9 remains useful organically on YouTube and LinkedIn, and declaring it dead is a LinkedIn posture, precisely.

How much does the second ratio really cost on a quote?

A supervised 4:5 reframe from a 9:16 master is billed at 10 to 20% of the master’s price; a re-edit genuinely adapted to the placement goes up to 40-70%. Between the two, it all depends on what you put back in play: the framing alone, or the framing plus the hook. These ranges come from our internal 2026 rate cards for vertical paid creative, not from published industry data.

The three billing models, and the trap of the third

First model: adaptations are included in the price of the creative, with a capped number written in black and white (“1 master + 2 ratios”). This is the most readable. Second model: a flat fee per adaptation, billed individually. Honest too, provided the unit price appears on the quote and not in an email. Third model: “unlimited adaptations”. Be wary. In most of the cases we audit, “unlimited” means unsupervised automatic export, in other words the line worth 0% in the table above, sold as a commercial advantage.

This detail completely changes how you compare two proposals. A quote at €420 per creative with two supervised ratios and a quote at €350 per creative with “all formats” do not cover the same deliverable. We have detailed the mechanics in the Reels quote, line by line, and the method for putting two offers on the same basis in comparing two video production quotes. The rule is simple to remember: two quotes that do not include the same number of supervised ratios are not comparable, full stop.

Always ask: “is the 4:5 version cropped by an editor or by a preset?” The answer tells you everything about the rest of the quote.

How do you shoot once to deliver 9:16 and 4:5 without sacrificing either?

You frame in 9:16 with a protected 4:5 area in the centre: everything that carries information, face, product, text, price, lives inside the centred 1080×1350 rectangle, and the rest of the frame is only set dressing. This discipline is decided on set, with the guides displayed on the monitor, not three weeks later in front of the timeline.

The maths is trivial, which is what makes the method robust: in a 1080×1920 master, extracting a 1080×1350 means cutting 570 px of height, without touching the width and with no loss of definition. The subject does not move horizontally. Everything comes down to vertical placement.

The 8-point shoot checklist

• The talent’s eye line sits in the upper third of the 4:5 rectangle, never within the top 130 px of the 9:16.
• Product held at chest height, horizontally centred. A product held out at arm’s length overhead falls outside the 4:5.
• Subtitles anchored at the vertical centre, not 100 px from the bottom. It is counter-intuitive for an editor from TV, and it is non-negotiable.
• On-screen text at a minimum of 48 px capital height on a 1080-wide frame. Below that, it is illegible on a 6-inch screen at 30 cm.
• Logo at top left, never at the bottom or on the right: that is where TikTok’s button column and the Meta caption sit.
• A 150 px margin kept on the right in every shot where a graphic element appears.
• Interesting set dressing in the top and bottom bands of the 9:16: they will disappear in 4:5, so they must enrich the shot without carrying information.
• Systematic validation of the hook in both crops before striking the set.

This last point deserves a pause. A hook that relies on a sweeping gesture, full-screen text or an entrance from the top of the frame does not survive the switch to 4:5: the promise arrives cut off, and the creative loses its retention at second 1. We have formalised how to measure that moment in this article on the video ad hook. Keep the short version: a hook that is illegible after cropping is no longer a hook, it is a cutaway.

Should you shoot in 1080p or 4K?

The answer depends on what you want to be able to do in the edit, and it is less clear-cut than people say.

In every case, we deliver in 1080. Platforms re-encode aggressively on playback, and a 300 MB 4K export adds nothing visible for the end user; it just slows down your approval round trips.

How do you test 9:16 against 4:5 without kidding yourself?

A ratio test is only valid if both versions run on the same placement, with the same targeting, the same budget and the same hook: otherwise you are not testing the ratio, you are testing the inventory. It is the mistake we see in nine test readings out of ten.

The typical scenario: the advertiser pushes 9:16 on Reels and 4:5 on Feed, compares the CPAs, and concludes that “9:16 works better”. They have just compared two audiences, two auction mechanics and two contexts of attention. The ratio is only one variable of three, and not the heaviest.

The minimum protocol

• Only one placement activated per test. Instagram Feed alone, or Reels alone. No Advantage+ placements during the reading phase.
• Two twin ad sets, same audience, same daily budget, same attribution window.
• Same hook, word for word, same edit. Only the framing changes.
• Learning phase exited before any conclusion. Below that, you are reading noise.
• Metrics read in this order: hold rate at 3 seconds, completion rate, and only then CPA. CTR alone says nothing about framing.

The misconception to abandon

You regularly read that “the algorithm penalises 4:5 in Reels”. No platform documentation describes such a penalty, and we have never managed to isolate one in our own tests. What is measurable is something else: a 4:5 in Reels takes up less screen area, lets the surrounding interface show, and visually signals “recycled ad”. Attention drops, engagement signals drop, distribution follows. The mechanism is behavioural, not algorithmic. The practical consequence is the same, but the explanation matters: it tells you what to fix, the framing, not a hidden setting.

What we don’t know, and need to own up to: the performance gap between a native 9:16 and a reframed 4:5 varies enormously depending on the type of creative. On UGC talking heads, we see small gaps, sometimes within the margin of error. On creatives with a strong graphic component or dense text, the gap becomes clear. Nobody can give you a single figure valid for every brand, so be wary of anyone who does. For e-commerce-specific issues, we have gathered formats and figures in this guide to e-commerce vertical video.

The real trade-off is not 9:16 vs 4:5

When a brand asks us to settle between 9:16 and 4:5 video for advertising, the question behind it is almost always about budget: “how many creatives can I produce with what I have?” Our answer comes down to one trade-off: at a constant budget, we favour the volume of concepts: ten concepts in 9:16 with a supervised 4:5 reframe deliver better results on our campaigns than five multi-format concepts. The volume of concepts tested weighs more than the formatted perfection of each asset. Once the framing discipline is in place, the ratio stops being a topic and becomes a box to tick in the delivery process. And that is exactly where it belongs.

Frequently asked questions

Should you shoot in 1080p or 4K to deliver both ratios?

Shoot in 4K if you want to be able to reposition or zoom in the edit: that is what makes the double export comfortable. A 1080×1920 master already lets you extract a 4:5 at 1080×1350 without loss, since you are only cutting height. Deliver in 1080 in every case; platforms re-encode.

What is the most common video format today?

Two answers depending on what you count. In volume of existing files, 16:9 still largely dominates, a legacy of twenty years of web and TV video. In mobile ad impressions, 9:16 has been the majority since the explosion of TikTok, Reels and Shorts. For paid social in 2026, the working reference is 9:16.

What exactly is the 9:16 format in pixels?

1080 pixels wide by 1920 high, a ratio of 0.5625. It is the standard delivery resolution requested by TikTok, Instagram Reels, Facebook Reels, Stories and YouTube Shorts. You can deliver larger (2160×3840), but platforms re-encode on playback and the visible gain is nil.

Is the 1:1 format dead in advertising?

For paid social, yes. Square no longer wins any placement: it loses height in the feed against 4:5 and loses the whole screen against full-screen 9:16. It remains marginally useful for product thumbnails or certain partner integrations, never as the main advertising master.

Can you send a single asset and let automatic placements handle it?

Technically yes, the campaign will run. But the platform crops blindly: text cut off, gaze off-centre, CTA hidden by the interface. It is the leading cause of a creative that “doesn’t perform” when the creative is not the problem. Always open the per-placement preview before launching.

How many ratios should you deliver per creative in a monthly subscription?

Two are enough in the vast majority of cases: a 9:16 master and a supervised 4:5 reframe. Add a 16:9 only if you activate in-stream or long-form YouTube. Insist that the number of supervised ratios be stated explicitly in the contract: “unlimited formats” almost always means uncontrolled automatic export.