Scrape YouTube video transcript with JavaScript

Preview

The API is in early access. Ask for a key; the examples use api.socialscrape.io.

Set up

You need Node 18 or newer. It has fetch built in, so there is nothing to install.

export SOCIALSCRAPE_API_KEY=ss_live_...

The script

Save as scrape.mjs and run node scrape.mjs. It calls GET /v1/youtube/video/transcript.

scrape.mjs

import { writeFileSync } from "node:fs";

const BASE = "https://api.socialscrape.io/v1/youtube/video/transcript";
const KEY = process.env.SOCIALSCRAPE_API_KEY;
const PARAMS = {
  id: "dQw4w9WgXcQ",
  language: "de",
};

// Follow a path through nested objects; undefined if any step is missing or null.
const pick = (obj, ...path) => path.reduce((o, k) => (o == null ? undefined : o[k]), obj);
const sleep = (ms) => new Promise((resolve) => setTimeout(resolve, ms));

// One request. Failures cost nothing; retry the ones the API marks retryable.
async function get(params) {
  for (let attempt = 0; attempt < 3; attempt++) {
    const url = new URL(BASE);
    url.search = new URLSearchParams(params).toString();
    const body = await (await fetch(url, { headers: { "x-api-key": KEY } })).json();
    if (body.ok) return body;
    const { code, message, retryable } = body.error;
    if (!retryable || attempt === 2) throw new Error(`${code}: ${message}`);
    await sleep(2 ** attempt * 1000);
  }
}

const body = await get(PARAMS);
const data = body.data;

writeFileSync("out.json", JSON.stringify(data, null, 2));
console.log("text:", String(pick(data, "text")).slice(0, 200));
console.log(`saved out.json, credits left: ${body.credits_remaining}`);

How it works

get() sends one request and retries the failures the API marks retryable. A failed request costs nothing.
The result is one object in data.
pick() reads nested fields and gives undefined instead of crashing when the platform returned null.
The whole object goes to out.json and a few fields are printed.

What you get back

These fields come from a recorded sample. The full field list is on the endpoint page.

Fields in the scriptSample

{
  "text": "Uns beiden ist die Liebe nicht fremd Du kennst die Regeln genau wie ich Für mich zählst nur du Das kriegst du sonst von keinem hier Ich will dir sagen, wie i..."
}

The short version

Without paging, saving or retries, the request is this.

const url = new URL("https://api.socialscrape.io/v1/youtube/video/transcript");
url.search = new URLSearchParams({
  id: "dQw4w9WgXcQ",
  language: "de",
}).toString();
const res = await fetch(url, {
  headers: { "x-api-key": process.env.SOCIALSCRAPE_API_KEY },
});
const body = await res.json();

if (body.ok) {
  console.log(body.data);
} else {
  console.error(body.error.code, body.error.message);
}

With the SDK

The JavaScript client does the retries for you. It is in preview and not published yet.

import { SocialScrape } from "socialscrape";

const client = new SocialScrape(); // reads SOCIALSCRAPE_API_KEY

const res = await client.youtube.videoTranscript({ id: "dQw4w9WgXcQ", language: "de" });
console.log(res.data);
console.log(res.credits_charged, res.credits_remaining);

What it costs

1 credit for captions; AI transcription 1 up to 2 minutes, then 1 per started minute. A failed request costs nothing. Add max_age_days to reuse a cached result for 0 credits. Results are kept 30 days.

The same request in nine languages.
YouTube video transcript API: sample response and every parameter.
The Python version.
All YouTube endpoints.

How to scrape YouTube video transcript with JavaScript