Aspect ratio, codec, safe zone, completion rate: the terms platforms and ad managers use, explained plainly, so your next export looks the way you intended.
This guide is general information for creators and businesses in the U.S., not legal advice. Copyright, licensing and drone rules depend on the facts and change over time; check the Copyright Office, the FAA or a lawyer for your situation.
Quick notes
- 1080×1920 at 9:16 in an MP4 with H.264 video and AAC audio covers Reels, TikTok and YouTube Shorts for organic posts.
- Keep text and logos inside each platform’s safe zone; on a 1080×1920 canvas the comfortable area is roughly 840 pixels wide.
- Between 24 and 30 fps is typical for social video, and Facebook’s export advice recommends staying at or below 30 fps.
- Platforms re-encode every upload, so a clean source file with the right specs is what protects sharpness after compression.
Most business owners meet social video specs the first time an upload comes back cropped, blurry or missing its caption. Platforms use a small set of technical terms over and over, and once you know what they mean, export settings stop feeling like guesswork. This glossary explains the terms you will see in help pages, editing apps and ad managers, in plain language. The numbers do change, so confirm the current requirements in each platform’s help center before an important launch.
Aspect ratio and resolution
Aspect ratio. The shape of your video, written as width to height. 16:9 is horizontal widescreen, 9:16 is vertical, and a 1:1 square sits comfortably in most feeds.
9:16. The vertical format used by Reels, TikTok, YouTube Shorts and Stories. On the YouTube mobile app, a vertical video appears larger than a horizontal one and covers about 75% of the screen, with feed content below; tap fullscreen with the phone held upright and it takes the whole screen.
16:9. The standard horizontal shape, usually exported at 1920×1080 for YouTube. The YouTube player adjusts automatically to any ratio between 16:9 and 9:16 without stretching or cutting off the picture, so near-misses are not a disaster there.
Resolution. How many pixels make up the frame, which drives how sharp the video looks. 1080p (1920×1080) is the standard for most social platforms. Ad systems accept a wide range, from 240×144 up to 4096×2160 for LinkedIn video ads, but extra resolution mostly gives the platform more detail to work with after it compresses the file.
Frame rate and why motion looks choppy
Frame rate (fps). The number of still images shown each second; between 24 and 30 fps is typical for social video. Facebook’s export advice recommends staying at or below 30 fps, with H.264 video, AAC audio and stereo sound at a 44,100 Hz sample rate.
Dropped frames. Frames that never make it into the finished file, usually because the computer was overloaded during recording or export. Playback stutters in a way that looks like a bad connection even when the source footage was fine, and no export setting repairs footage that was recorded badly.
Codec, bitrate and compression
Codec. The method used to squeeze video and audio into a file. H.264 for video paired with AAC for audio is the combination every major platform accepts.
MP4 and MOV. The two container formats that hold the encoded video and audio. Both are accepted nearly everywhere; our guide to MP4 or MOV covers when each format makes sense, especially for client work.
Bitrate. How much data each second of video carries. Set it too low and flat surfaces break into blocks, especially during motion.
Compression and transcoding. What the platform does to your upload: it re-encodes the file into several versions so it plays smoothly on different connections. Each pass throws away detail, which is why a clean source file with the right specs matters more than fancy settings.
File size limit. The maximum weight an upload can carry. TikTok, for instance, caps uploads at 500 MB. Oversized files get rejected at the upload screen rather than quietly compressed.
Safe zones and where platform UI covers your video
Safe zone. The part of the frame guaranteed to stay visible across placements. Google publishes safe zone templates for horizontal, vertical and square video ads, with a marked area for logos, products and text overlays so nothing important gets covered.
UI overlay. The buttons, captions, usernames and icons a platform draws on top of your video. They sit over your pixels, not inside them, so anything placed behind them is effectively invisible.
Platform margins. The safe areas differ by app on a 1080×1920 canvas. Guides place the comfortable center area at about 840×1350 pixels for Instagram and 840×1280 for TikTok, and roughly 960×1160 for YouTube Shorts, slightly left of center.
Studio tip: For Instagram Stories, leave roughly 14% of the frame, about 250 pixels at the top and bottom, free of text and logos, so the profile icon and call-to-action buttons do not cover them.
Hook, retention and watch time
Hook. The first second or two of a vertical video, when a viewer decides to keep watching or keep scrolling. Text on screen and a clear subject inside the safe zone both help.
Watch time. The total time viewers spend on your video. Platforms weigh it heavily when deciding how widely to distribute a clip.
Retention. How much of the video the average viewer actually watches. A steep early drop-off usually points to a weak opening rather than weak footage.
Completion rate. The percentage of viewers who watched to the end. Short videos make this number easier to raise, which is one reason short clips get pushed harder.
Thumbnails, covers and first frames
Thumbnail or cover. The still image shown before someone presses play, and the image that represents the video in grids and feeds. If you never set one, most platforms show the first frame by default, which is why choosing a cover yourself avoids an unflattering mid-blink freeze.
Letterboxing and cropping
Letterboxing and pillarboxing. Black bars added to fit a picture into a differently shaped space, above and below for letterboxing, at the sides for pillarboxing. YouTube adds pillarboxing automatically to 4:3 uploads so they fit a 16:9 player.
Cropping. What happens when a platform trims your edges instead of adding bars. Facebook Stories adds colored bars above and below vertical videos narrower than 9:16 rather than stretching them, so very tall text layouts can end up framed like a banner.
When the specs actually matter (and when they don’t)
For organic posts, one export covers almost everything: 1080×1920, 9:16, MP4 with H.264 video and AAC audio. That file posts cleanly to Reels, TikTok and YouTube Shorts. For horizontal YouTube uploads, 1920×1080 at 16:9 does the same job. If you also run ads, the stakes rise, because rejected or badly cropped creatives cost money, and some ad formats carry extra rules, such as a five-second minimum duration for Demand Gen video assets.
Specs stop mattering the moment they become an excuse not to post. A slightly soft phone clip with a clear message beats a perfectly specced video you never finish, and an audience watching on a phone screen forgives a great deal.
One decision does need thought before you shoot: which shape to build for. Our guide to horizontal or vertical video for social media walks through that choice, and if an upload comes out soft or blocky anyway, why video looks blurry after upload explains what the platform did to your file and how to export around it.
FAQs
What aspect ratio should I use for social media video?
For short-form vertical placements like Reels, TikTok and Shorts, export at 9:16 (1080×1920). For horizontal YouTube uploads, 16:9 at 1920×1080. The YouTube player also adjusts automatically to ratios anywhere between 16:9 and 9:16.
Why does my video get cropped or covered by buttons after upload?
Each platform draws its own interface on top of the video and trims edges when the shape does not match the placement. Keeping text and logos inside the platform’s safe zone prevents both problems.
What file format works on every platform?
An MP4 with H.264 video and AAC audio is accepted by every major social platform. Stay under each platform’s size limit; TikTok, for example, caps uploads at 500 MB.
Do specs matter for ordinary posts, not just ads?
Less, but they still help. A matching file keeps quality high after compression, while paid placements face stricter checks, and some ad formats add rules such as a five-second minimum duration.