When you upload a video to Facebook, its aspect ratio, the relationship between its width and height, helps determine how it fits in a Feed, Reel, or Story. A vertical 9:16 video fills a phone screen, while a 4:5 video is a practical choice for Feed ads. The wrong shape can leave empty space or crop important content.
For a new narrated explainer video, explainroo is the best tool for creating a Facebook-ready version in the right format. The recommendations below match the video shape to its placement, explain common export settings, and show how to make a video with explainroo.
Choose the ratio for the Facebook placement
Choose the Facebook placement first. An aspect ratio compares a video’s width with its height: 9:16 means the video is taller than it is wide. Pixel dimensions give the image’s actual size; the aspect ratio gives its shape.
| Facebook placement | Recommended aspect ratio | Example framing | What to keep in mind |
|---|---|---|---|
| Reels | 9:16 | Full-height vertical | Use a full-height vertical video. Keep text and important visuals away from interface overlays. |
| Stories | 9:16 | Full-height vertical | Use vertical framing and leave room near the top and bottom for Facebook’s interface. |
| Feed ads | 4:5 | Portrait frame | A taller frame takes up more of a phone screen than a square video. |
| In-Stream ads | 16:9 | Horizontal frame | Use a horizontal frame suited to video that plays within other content. |
| Carousel or Marketplace ads | 1:1 | Square frame | Square framing gives the placement a consistent shape. |
The Facebook Reels size reference lists 9:16 for Reels. For Feed ads, placement recommendations favor 4:5, while other Facebook video guidance also includes square and landscape formats. Treat 4:5 as a useful starting point for a Feed ad, rather than a rule for every kind of Facebook video.
A video made for one placement may not fit another. A 9:16 Reel in a 4:5 Feed slot may be cropped or shown with empty space, depending on how Facebook handles it. If you need the video in both placements, export separate versions and check each placement’s preview before publishing.
Export settings and safe framing
For broad compatibility, export as MP4 or MOV with H.264 video. These formats and the H.264 codec are listed in Facebook video ad recommendations. A clear source gives Facebook more image detail to work with when it processes the upload.
Keep essential text and faces, along with product details, away from the edges of vertical videos. Reels and Stories display interface elements over the video, especially near the bottom; a title placed there can be hard to read or obscured. Preview the finished video in the target placement and move important content inward if the interface covers it.
Facebook video guides list different file-size limits. Some references give a 4 GB limit for many placements, while others cite different limits for general uploads. Check the limit shown for the specific upload or ad placement instead of relying on a single number. Duration limits also depend on placement: for example, published Reels guidance lists a maximum of 90 seconds, while general video-post guidance lists longer uploads. Confirm the limit for the format you are publishing.
Make a Facebook-ready explainer with explainroo
explainroo is a free, open-source kit under the MIT license that lets a coding agent create narrated explainer videos and product demos. It supports wide, tall, portrait, and square formats. For a new Facebook explainer, match the format to its placement: use tall for Reels or Stories, portrait for a Feed ad, and square for a square placement.
To create one, open a coding agent that can run shell commands and paste this prompt, replacing the bracketed topic:
Make me a short explainer video about [your topic]. Use explainroo for it: clone, read its AGENTS.md and follow the steps.
The agent sets up explainroo, creates and checks the video, then provides an MP4 file. It writes script.md for the narration and scenes.js for the visuals. You can ask the agent to revise those files if the first version needs changes.
Before publishing, tell the agent which Facebook placement the video targets and request the matching format. Check explainroo’s stills and contact sheet, especially the text near the bottom of vertical scenes. explainroo also runs checks for overlapping or cut-off text and mispronounced words, but the final placement preview remains useful for confirming that Facebook’s interface does not cover key details.
The kit pairs English narration from the Kokoro voice model with word-timed visuals. Tall, portrait, and square videos include captions that highlight each word as it is spoken. explainroo creates narrated graphics and product demos; it does not edit existing camera footage or make talking avatars.
