A simple Youtube player js (base.js) minifier to extract required functions to solve url query transformation challenge, based on youtubei.js.

A proper js runtime¹ is needed to perform the extraction, but a lightweight js engine (such as quickjs or dukpy) is enough to run the extracted js code.

Clone the repository and install the required packages.

git clone https://github.com/alive4ever/yt-js-extractor
cd yt-js-extractor
# Use npm with nodejs to install dependencies
npm install
# Use the main js executable for deno and bun
# deno install
# bun install

An optional argument player_id can be used to instruct extraction for specific player_id. If not specified, the player_id will be determined by youtube.js.

# For node 22 or later
PLAYER_ID="ef5f17ca"
node yt_js_extractor.ts "$PLAYER_ID" | jq -r .output > js_sigfuncs_${PLAYER_ID}.js
# For node 20 (untested)
npx --yes tsx yt_js_extractor.ts "$PLAYER_ID" | jq -r .output > js_sigfuncs_${PLAYER_ID}.js
# node and bun can execute the ts file directly

Thanks @LuanRT for youtubei.js project.

MIT License