Subtitle & Captions API

Render trending subtitles. For ecommerce, agencies, and AI video platforms.

No credit card required

Trusted by leading creators and businesses worldwide

API workflow

Upload a clip, fire a task, get a webhook. We handle transcription, styling, and rendering — you get the MP4 when it's ready.

1
Upload your video
POST the file to /videos. We stream it to storage and hand you back a videoId.
POSTPOST /videos
2
Create the captioning task
One POST starts transcription, styling and rendering with your chosen template. Add a notification webhook to skip polling.
POSTPOST /videos/:id/task
3
Receive the webhook
We POST status updates to your endpoint as the render moves through queued → processing → completed.
HOOKPOST → your URL
4
Download the rendered MP4
Burned-in subtitles, served from a global CDN. No watermark. MP4 ready for any social platform.
GETGET downloadUrl

Step 1 / 4·~2s

1import { readFileSync } from "node:fs";

3const form = new FormData();

4form.append(

5 "file",

6 new Blob([readFileSync("clip.mp4")]),

7 "clip.mp4",

8);

10const { id: videoId } = await fetch(

11 "https://api.zapcap.ai/videos",

12 {

13 method: "POST",

14 headers: { "x-api-key": process.env.ZAPCAP_KEY! },

15 body: form,

16 },

17).then(r => r.json());

POST /videos·Upload your video

Boost views, engagement, and retention of your videos in seconds.

🌎 90+ Languages
Make your content globally accessible by reaching audiences worldwide with our 90+ language subtitle options.
🎥 Magic B-Rolls & Transitions
🏷️ Auto Descriptions & #Hashtags
🔊 Sound Effects & Background Music
💯 Auto Accurate Captions
🥳 Trendy Templates & Emojis