Merge video clips, voiceover, and captions into an MP4 with Apify

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Last update

Last update 18 days ago

Quick overview

Assemble 1–10 supplied clips, optional narration and timed SRT captions into an MP4, up to 60 seconds, from n8n Cloud. Try the cached demo first. Real renders cost $0.20 per successfully assembled video. Failed renders incur no video-assembly charge.

How it works

Starts when you run the workflow manually.
Builds a video job payload that includes a list of clip URLs plus optional voiceover and SRT captions, along with orientation, fit mode, and a maximum duration.
Sends the job to the Apify Short Video Assembler API to scale/crop or pad clips, concatenate them, add the voiceover, and burn in captions into a single MP4.
Returns the resulting public MP4 URL along with the render duration and job status.

Setup

Create an Apify account and copy your Apify API token from Apify Console.
In the HTTP request to Apify, add an HTTP Header Auth credential with Authorization: Bearer <YOUR_APIFY_TOKEN>.
First run with clips: [] for the cached demo. When ready to pay $0.20 for successful assembly, replace the entire JSON in Set video job with the sample below or your own public media URLs, then execute manually.

Requirements

Apify account (free tier works) and its API token
Video clips and audio at public http(s) URLs
Pay per use: $0.20 per finished video on Apify, no subscription

Customization

Set orientation to vertical (1080x1920), horizontal or square, and fit to crop or pad
Limit length with max_seconds (1-60)
Swap the manual trigger for a schedule, form or webhook, and send the video URL to YouTube, Google Drive or Slack

Additional info

Watch the narrated setup guide

From free demo to your own MP4 (1:47). Covers credentials, the cached demo, supplied media, billing and saving your result. Synthetic narration; the Actor itself does not generate voices or caption timings.

Free demo versus real video

Empty clips returns the cached 12-second demo. In the Assemble video on Apify node output, demo=true and charged=false identify a demo. For your own media, demo=false; charged reports the actual charge result. The final Return video URL node currently selects only URL, duration and status.

Optional first real render — $0.20 on successful assembly

Copy this JSON into Set video job only when ready for a paid run. This eight-second silent example uses a NASA public-domain clip from our showcase, with supplied caption timing. NASA does not endorse this tool. External media availability can change.

{
  "clips": [
    "https://upload.wikimedia.org/wikipedia/commons/f/f1/SDO_Video_Toolkit_%28SVS14126_-_Canyon_of_Fire_New-Slow%29.webm"
  ],
  "voiceover_url": null,
  "captions_srt": "1\n00:00:00,000 --&gt; 00:00:04,000\nMy first assembled video\n\n2\n00:00:04,000 --&gt; 00:00:08,000\nFootage: NASA (public domain)\n",
  "orientation": "vertical",
  "fit": "pad",
  "max_seconds": 8
}

Limits and billing

You supply the clips, narration and caption timing. No generated media, automatic caption timing or per-clip trimming. Original clip audio is discarded; add your own voiceover_url for narration. Up to 10 clips, 60 seconds output, 200 MB per file and 600 MB total downloads. Save the finished MP4 to your own storage promptly: the link is not permanent.

Failed renders incur no video-assembly charge. Demo runs have no video-assembly charge; compute is still incurred by the operator. If a request times out, check Apify Runs before retrying: the original render may still be running.

Disclosure: I built and operate this paid Apify Actor.