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Your tools are ready — preview running in one terminal, AI assistant in the other. Now let’s create a real promotional video, step by step. We will build a 30-second personal brand intro — but the same workflow works for any type of video. You will generate voiceover audio, create a sound effect, build the video composition, and render the final MP4.
Voice or typing — both work. If you have Wispr Flow running, just start speaking your prompts. Otherwise, copy and paste them or type your own version. Your AI assistant understands natural language either way.

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The vibe coding loop

This is how you will work throughout this tutorial: Describe. Preview. Refine. Repeat until you love it — then render.
1

Generate your voiceover audio

Before building the video, let’s create the voiceover. You will tell your AI assistant to call the ElevenLabs API and generate an audio file from your script.
In your Gemini CLI terminal, say or type this prompt:
Say this or copy this prompt
I need you to generate a voiceover audio file using the ElevenLabs API.

My ElevenLabs API key is: [paste your API key here]

Please write a Node.js script that:
1. Sends this text to the ElevenLabs text-to-speech API:
   "Hi, I'm [Your Name]. I'm a creative problem-solver transitioning
   into tech, and I'm passionate about building tools that help people.
   Let's connect."
2. Uses the voice ID "21m00Tcm4TlvDq8ikWAM" (Rachel voice)
3. Saves the audio output as public/voiceover.mp3

Then run the script.
Replace [Your Name] with your actual name. Feel free to change the voiceover text to something that sounds like you — this is your personal brand intro.
Your AI assistant will write a small Node.js script, run it, and save the voiceover audio as public/voiceover.mp3.
The AI asks for permission? If your AI assistant asks to approve running a script or creating a file, type y and press Enter. This is normal — it is asking your permission before taking action.
Your AI assistant wrote a small Node.js script that:
  1. Sent your voiceover text to ElevenLabs’ text-to-speech API
  2. Received audio data back from ElevenLabs’ servers
  3. Saved it as an MP3 file in your project’s public/ folder
The entire process happens in a few seconds. You described what you wanted in plain English, and AI handled all the technical details.
The free tier includes these built-in voices. Replace the voice ID in your prompt:
VoiceIDStyle
Rachel21m00Tcm4TlvDq8ikWAMCalm, professional (default)
BellaEXAVITQu4vr4xnSDxMaLWarm, friendly
AntoniErXwobaYiN019PkySvjVConversational, male
ElliMF3mGyEYCl7XYWbV9V6OYoung, energetic
JoshTxGEqnHWrfWFTfGW9XjXDeep, authoritative
AdampNInz6obpgDQGcFmaJgBClear, neutral, male
SamyoZ06aMxZJJ28mfd3POQWarm, narrative
DomiAZnzlk1XvdvUeBnXmlldConfident, bold
Want more options? Browse all voices at elevenlabs.io/voice-library to hear previews. The built-in voices above work on the free API tier.
Common causes:
  • Invalid API key: Double-check that you copied the full key with no extra spaces.
  • Free tier limit reached: Check your usage at elevenlabs.io under Profile. The free tier is 10,000 characters per month.
  • Network error: Make sure you have an internet connection. Try again in a few seconds.
If the error message is confusing, paste it into your AI assistant and ask: “What does this error mean and how do I fix it?”
2

Generate a sound effect

Now let’s create a sound effect to use in your video transitions.
Say this or copy this prompt
Now generate a sound effect using the ElevenLabs sound effects API.
Use my same ElevenLabs API key.

Create a short, subtle whoosh transition sound — about 1.5 seconds long.
Save it as public/swoosh.mp3
ElevenLabs can create any sound from a text description. Try “gentle bell chime,” “keyboard typing sounds,” “crowd applause,” or “ocean waves.” Experiment with different descriptions — the more specific you are, the better the result.
Video TypeSound Effect Prompt
Personal brand”subtle whoosh transition, professional”
Event invitation”gentle bell chime notification”
Portfolio showcase”soft keyboard typing sounds”
Social media tip”upbeat pop notification sound”
Freelance pitch”confident drum hit accent”
Thank-you video”warm, soft chime”
You can generate multiple sound effects and use different ones at different points in your video.
3

Create your video composition

Now for the main event — describe your video and let AI build it. This is where everything comes together.
Say this or copy this prompt
Create a Remotion video composition for a 30-second personal brand intro.

The video should have:
- A dark gradient background (dark purple to dark blue)
- My name "[Your Name]" appearing with a smooth fade-in animation at 1 second
- Below it, my tagline "Transitioning into Tech" sliding in from the left at 2 seconds
- Three bullet points appearing one by one at 3, 4, and 5 seconds:
  • Creative problem-solver
  • Quick learner
  • Passionate about helping people
- A "Let's connect" call-to-action fading in at 7 seconds
- Use the voiceover audio from public/voiceover.mp3 starting at 0.5 seconds
- Play the swoosh sound from public/swoosh.mp3 on each text transition
- Use TailwindCSS for all styling
- Make it 1080x1920 (vertical, for social media)
- The video should be 15 seconds long at 30fps

Create this as a new composition in the Remotion project and
register it in src/Root.tsx.
Check the preview! After the AI finishes creating files, switch to your browser at http://localhost:3000. You should see your video playing with the animations and audio. If the preview is not updating, try refreshing the browser.
Replace [Your Name] with your actual name. Feel free to change the tagline, bullet points, and colours to match your personal brand.
Your AI assistant created several files in the src/ folder:
  • A React component (.tsx file) that defines the video’s visual layout — text, colours, animations
  • Uses Remotion’s <Audio> component to include your voiceover and sound effects
  • Uses Remotion’s animation utilities (useCurrentFrame, interpolate, spring) for smooth transitions
  • Registered the new composition in src/Root.tsx so Remotion knows about it
You never need to understand or edit these files. The AI reads and writes them for you.
4

Review and refine

Watch the preview in your browser. It probably will not be perfect on the first try — that is expected and part of the process. Here are some refinement prompts to try:Adjust sizing and layout:
Say this or copy this prompt
The text is too small on mobile. Make the name 80px and the tagline 48px.
Also add a subtle glow effect behind the name text. Keep everything else the same.
Change the colour scheme:
Say this or copy this prompt
Change the background gradient from purple-blue to dark teal to navy blue.
Make the text white with a slight drop shadow for better readability.
Fix audio timing:
Say this or copy this prompt
The voiceover timing is off — the speech starts before the name appears.
Move the voiceover start to 1.5 seconds so it plays after the name fades in.
Add visual flair:
Say this or copy this prompt
Add a subtle animated particle effect in the background — small dots slowly
floating upward, very low opacity. Keep it elegant, not distracting.
The vibe coding loop: Describe → Preview → Refine. Each time you give a prompt, the AI updates the code and the preview refreshes. Keep refining until you love the result. There is no limit on how many times you can iterate.
Be specific in your feedback. Instead of “make it look better,” try “make the name text larger, change the background to dark blue, and slow down the fade-in animation.” The more specific you are, the better the AI can help.
5

Render your final video

Happy with the preview? Let’s render the final MP4 file.
Say this or copy this prompt
Render this video composition to an MP4 file. Use the Remotion render
command and output it as out/my-promo-video.mp4
Rendering takes 1 to 3 minutes depending on your computer and the video length. You will see a progress bar in the terminal. The final MP4 file will be saved in the out/ folder inside your project.
6

Watch your video

Open the rendered video and see the final result:
Open File Explorer and navigate to your project’s out/ folder, then double-click my-promo-video.mp4. Or run:
Copy this command
start out/my-promo-video.mp4
You should see your finished promotional video — with animated text, professional voiceover, and sound effects.

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What just happened?

Let’s recap what you did:
  1. Generated a voiceover — AI called the ElevenLabs API to turn your script into professional audio
  2. Created a sound effect — AI generated a custom swoosh transition from a text description
  3. Built a video composition — AI created animated text, backgrounds, and integrated your audio files
  4. Refined the design — You described changes and AI updated the video in real time
  5. Rendered to MP4 — AI ran the render command and produced a video file you can share anywhere
The key insight: you described everything in plain English. You never opened video editing software, never wrote code, never touched a timeline. AI handled all the technical work — your job was to be the creative director.

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Troubleshooting

The AI may have created a file with a syntax error. Ask your AI assistant:
The preview is showing an error. Can you check the console output and fix any issues?
You can also try refreshing the browser. If the issue persists, check that Terminal 1 (the preview server) is still running.
Remotion’s preview may not autoplay audio. Try clicking the play button in the Remotion preview controls. Also verify that the audio files exist:
Check if public/voiceover.mp3 and public/swoosh.mp3 exist and are valid audio files.
Common causes:
  • Invalid API key: Double-check your key — no extra spaces or missing characters.
  • Free tier limit: You may have used your monthly quota. Check usage at elevenlabs.io.
  • Rate limit: Wait a few seconds and try again.
Paste the error message into your AI assistant and ask it to explain and fix the issue.
Ask your AI assistant:
The render command failed. Can you check what went wrong and try again?
Common causes: missing audio files, composition not registered in Root.tsx, or a code error. The AI will usually identify and fix the issue.
Tell your AI assistant the exact duration you want:
Change the video duration to exactly 20 seconds at 30fps. Adjust the animation
timing so everything fits within 20 seconds.
Wispr Flow may occasionally mishear technical terms. You can review and correct the text before pressing Enter. If voice input is causing too many errors, switch to copying and pasting the prompts instead.
Congratulations — you created a real promotional video using only natural language! Head to Keep going for more video ideas, advanced techniques, and ready-to-use prompts.