Meta

In-stream Video Ad Specs 2026

Design at 16:9 (1920 x 1080). Below is the full spec, the practical rules for getting it right, and a free validator to check your own files.

Specs last verified July 2026

In-stream Video ad specifications
PlatformMeta
Recommended aspect ratio16:9
Accepted ratios16:9, 1:1
Recommended resolution1920 x 1080
Minimum resolution600 x 336
File typesMP4, MOV
Max file size4 GB video
Video length5 sec – 10 min (5–15 sec recommended)
FormatsVideo
Primary text125 recommended
Headline27 recommended (up to 40 shown)

The one remaining placement where landscape 16:9 is the right call — it plays before/inside other videos. Front-load the message; the first seconds are often non-skippable but short.

How to get In-stream Video right

Design it right

In-stream video is the one Meta placement where landscape 16:9 at 1920 x 1080 is still the right choice - the ad plays before or inside other video content, which is horizontal. A 1:1 square is accepted and travels better across placements, but for a purpose-built in-stream creative, 16:9 fills the player. Vertical files pillarbox badly here, so a 9:16 Reels master is the wrong file for this slot.

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The common mistake

The practical constraint is length and attention: in-stream ads often play in a short, partly non-skippable window, so front-load the message and brand in the first few seconds. Meta's own guidance leans toward 5 to 15 seconds for these placements even though the technical ceiling is much higher. This is video-only - no static image, no carousel. Because most teams build 4:5 and 9:16 first, in-stream is frequently the placement with no matching file; adding a 16:9 or at least a 1:1 cut keeps it from being padded.

Check your creative against In-stream Video

Drop your files into the free creative validator - it reads each file's dimensions in your browser, tells you which placements it covers, and flags the aspect ratio your set is missing. For a single file, the aspect ratio checker gives a per-placement verdict.

In-stream Video FAQ

What is the aspect ratio for in-stream video ads?
16:9 landscape at 1920 x 1080 is the native fit, since in-stream ads play inside other horizontal video. 1:1 is also accepted and travels better across placements.
How long should an in-stream video ad be?
Meta leans toward 5 to 15 seconds for in-stream, even though longer is technically allowed. The window is short and often partly non-skippable, so front-load the message and brand in the first few seconds.
Can I use a vertical video for in-stream?
It runs but pillarboxes badly - a 9:16 file leaves large empty bars on the sides of a horizontal player. Use a 16:9 or 1:1 cut for in-stream instead of a Reels master.
Is in-stream video image or video only?
Video only. There is no static image or carousel option for in-stream. Supply a 16:9 (or 1:1) MP4 or MOV up to 4 GB.

Other placement specs

One concept, every ratio, one ad

Once each concept has its 4:5 and 9:16 cuts, uplads reads the placement in every filename and merges them into a single multi-placement ad - the right cut in each surface - across a whole bulk launch.