yt-dlp External JavaScript Solver

0.8.0 · active · verified Sat Apr 11

yt-dlp-ejs is a specialized Python library that provides external JavaScript execution capabilities for yt-dlp, the popular video downloader. It solves YouTube's signature and n-parameter challenges by bundling JavaScript solvers that work across multiple runtimes such as Deno, Bun, Node.js, and QuickJS. Currently at version 0.8.0, it maintains a frequent release cadence to adapt to YouTube's player code changes.

Warnings

breaking yt-dlp is often pinned to a specific compatible version of yt-dlp-ejs. Using mismatched versions can lead to 'No suitable player found' or 'Signature/n-parameter decryption failed' errors, especially for YouTube videos.
Fix: Always install/update yt-dlp-ejs concurrently with yt-dlp, preferably by installing `yt-dlp[default]` or ensuring versions match the `yt-dlp`'s `pyproject.toml` definition. `pip install -U yt-dlp yt-dlp-ejs` is recommended.
gotcha yt-dlp-ejs *requires* an external JavaScript runtime (e.g., Deno, Node.js, Bun, or QuickJS) to be installed on your system. Without one, yt-dlp-ejs cannot function, and YouTube support in yt-dlp will be limited or broken.
Fix: Install a supported JavaScript runtime (Deno is highly recommended) and ensure it's accessible in your system's PATH. You can also specify the runtime path using yt-dlp's `--js-runtimes` option (e.g., `--js-runtimes deno:/path/to/deno`).
gotcha YouTube frequently updates its player code, which can break yt-dlp-ejs's decryption logic. This necessitates frequent updates to yt-dlp-ejs.
Fix: Regularly update `yt-dlp` and `yt-dlp-ejs` to their latest versions to ensure compatibility with YouTube's most recent player changes. `pip install -U yt-dlp yt-dlp-ejs`.
gotcha If building from source or performing advanced integrations, be aware that internal changes (like exposing `window` as `self` in 0.8.0 or making `window` a local in 0.2.0) might affect custom JavaScript code relying on these globals.
Fix: Review the `yt-dlp-ejs` changelog and ensure your custom JavaScript or integration code is compatible with the changes in global scope handling if directly calling the internal solver scripts.

Install

pip install yt-dlp-ejs Install yt-dlp-ejs
pip install "yt-dlp[default]" Install yt-dlp with EJS support

Imports

yt_dlp_ejs.yt.solver
```
import yt_dlp_ejs.yt.solver
```
Typically, end-users do not directly import this library; yt-dlp uses it automatically. This import is for advanced use cases like custom video extractors or direct interaction with solver APIs.

Quickstart

This quickstart demonstrates how yt-dlp-ejs is used implicitly by yt-dlp to decrypt YouTube video URLs. No explicit Python code is usually needed to interact with yt-dlp-ejs directly when using yt-dlp. It also includes a check for direct import for debugging purposes.

import os
from yt_dlp import YoutubeDL

# yt-dlp-ejs is automatically detected by yt-dlp if installed.
# Ensure a JS runtime (Deno, Node.js, Bun) is available in your PATH
# or specified via yt-dlp options (e.g., --js-runtimes deno:/path/to/deno)

# Example: Download a YouTube video that requires signature/n-parameter decryption
# For this to work, yt-dlp-ejs and a JS runtime must be correctly set up.

url = 'https://www.youtube.com/watch?v=dQw4w9WgXcQ' # Example URL

with YoutubeDL({'format': 'bestvideo[ext=mp4]+bestaudio[ext=m4a]/best[ext=mp4]/best'}) as ydl:
    info = ydl.extract_info(url, download=False)
    print(f"Title: {info.get('title')}")
    print(f"Uploader: {info.get('uploader')}")
    print(f"Duration: {info.get('duration_string')}")
    print("yt-dlp-ejs (and a JS runtime) was implicitly used for decryption.")

# To explicitly verify the presence of EJS solvers (for advanced debugging)
try:
    from yt_dlp_ejs.yt.solver import core, lib
    print("yt_dlp_ejs solvers (core, lib) are importable.")
    # Example of accessing a solver, though not typically done by end-users:
    # core_js = core()
    # print(f"Core solver JS size: {len(core_js)} bytes")
except ImportError:
    print("yt_dlp_ejs solvers are not directly importable or installed.")

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