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AI Video Generator for Social Media: Short Videos Guide

By PostMediaAI7 min read

An AI video generator creates short video clips from a text prompt, an image or a script. On social media it works well for short visual hooks, animated explainers, background footage and product concept visuals. It does not replace filming your real product, team or customers, and realistic AI video usually needs an AI label on major platforms.

The short version: decide what the video needs to show, write a prompt with subject, motion, style and format, generate a few options, add your own text and captions, check the platform’s labeling rules and schedule it with a caption written for each channel.

What AI video is good for

  • Short visual hooks at the start of a video, such as an animated title or scene.
  • Explainer visuals for ideas that are hard to film.
  • B-roll and background footage behind on-screen text.
  • Seasonal or themed clips for announcements.
  • Concept visuals for ideas, campaigns or moods.

What to film yourself instead

  • Your real product, service, location or team.
  • Customer stories and results.
  • Tutorials where viewers need to see the real steps.
  • Anything a viewer could mistake for a real event or person.

If you already have long recordings, such as webinars, podcasts or talks, cutting them into short clips is often more effective than generating new footage. See our guide to turning long videos into short clips.

Writing a video prompt

  1. Subject: who or what is on screen, specifically.
  2. Action and motion: what moves and how the camera moves.
  3. Style: realistic, animated, illustrated, stop-motion look.
  4. Setting, light and color: where it happens and how it looks.
  5. Length and format: a few seconds, vertical 9:16 for short-form feeds.

Example: "Animated illustration of a calendar page flipping from Monday to Friday, each day filling with small colorful post cards, soft pastel colors, slow camera push-in, vertical 9:16, no text."

Leave text out of the prompt and add titles and captions in an editor, where you can control spelling and timing.

Formats for each platform

  • YouTube Shorts: square or vertical videos up to three minutes are treated as Shorts (YouTube Help).
  • Instagram Reels: designed for vertical, full-screen viewing; check Instagram’s current size guidance (Instagram Help).
  • TikTok: a vertical, full-screen format; check TikTok’s upload requirements (TikTok Support).
  • Pinterest video Pins: a 9:16 ratio at 1,080 by 1,920 pixels is recommended for full-screen video (Pinterest Help).
  • LinkedIn and Facebook: vertical and square both work in feeds; landscape suits longer videos.

Making AI clips work as social posts

A generated clip is raw material, not a finished post. To turn it into something people watch:

  1. Put the hook in the first seconds, on screen and in words.
  2. Add captions so the video works for anyone watching with the sound off, and for accessibility.
  3. Add your own voiceover or narration if the clip explains something.
  4. Keep it short; cut anything that does not move the message forward.
  5. End with one clear next step, if the post needs one.
  6. Write a separate caption for each platform.

Labeling AI video

Platforms have specific rules for realistic AI video:

  • Meta says it requires people to use its disclosure tool when posting photorealistic video or realistic-sounding audio that was digitally created or altered (Meta).
  • TikTok requires creators to label AI-generated content with realistic images, audio or video (TikTok Support).
  • YouTube requires disclosure of realistic altered or synthetic content at upload, in YouTube Studio (YouTube Help).

Clearly animated or fantastical clips are generally treated differently from realistic ones, but check each platform’s current policy before posting.

Choosing between generating and filming

A simple way to decide which approach to use for each video idea:

  • If the video shows your real product, place, people or results, film it.
  • If the video explains an abstract idea, a process or a concept, AI-generated visuals can work well behind your narration.
  • If you already have long recordings, clip them first; you get real footage without new filming.
  • If you need a quick seasonal or themed visual, generate it and add your own text.

Many accounts mix all three: a filmed clip on Monday, a clipped moment from last month’s webinar on Wednesday and an animated explainer on Friday. The mix keeps the feed varied while keeping real footage at the center of anything that makes a promise.

A weekly AI video workflow

  1. Pick one or two ideas that need a visual.
  2. Write the script or on-screen text first.
  3. Generate clips that fit the script, in vertical format.
  4. Edit: add text, captions and audio.
  5. Check labeling rules for each platform.
  6. Schedule the same video to Reels, TikTok and Shorts with captions written for each.

For timing and batching, see the social media scheduling guide.

Creating video in PostMediaAI

PostMediaAI can generate images and short videos, cut long videos into clips and keep media in a shared library (PostMediaAI features). You can attach a video to a post, have AI draft the caption for each channel you choose, edit it, and schedule it to TikTok, Instagram, YouTube and other channels from one calendar. See pricing for what each plan includes.

FAQ

Is there a free AI video generator for social media?

Some AI video tools offer free tiers with limits on length, quality or watermarks. Check the terms for commercial use before posting generated videos for a business.

What is the best AI video generator for social media content?

It depends on what you need: realistic footage, animation or clips from existing recordings. If you want to generate, caption and schedule in one place, a tool that combines video with scheduling saves steps.

Can AI make videos for TikTok and Reels?

Yes. AI tools can generate short vertical clips you can edit and post. Add captions, a clear hook and your own voice or text, and label realistic AI content as the platforms require.

Do I have to label AI-generated videos?

On TikTok, Meta platforms and YouTube, realistic AI-generated or altered video generally needs to be disclosed. Check each platform’s current rules for your type of content.

Related guides: AI Social Media Post Generator: One Idea, Every Channel, AI Image Generator for Social Media: How to Use One Well and How to Keep Your Brand Voice When AI Writes Your Posts.

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