Solving PyTube HTTP 400 Bad Request Error

Problem Statement

Users encounter the HTTP Error 400: Bad Request when downloading long YouTube videos (approximately 100+ minutes) with PyTube. This error occurs despite the code working perfectly for shorter videos and previously functioning correctly. The core issue arises from YouTube's API changes that invalidate older PyTube authentication requests, particularly affecting videos with certain characteristics like length or region restrictions.

Symptoms include:

• HTTP Error 400: Bad Request tracebacks originating from urllib
• Failures only on long-duration videos (~100 minutes)
• Successful downloads of shorter videos with identical code
• Sudden appearance of errors without code changes

Recommended Solutions

1. Switch to pytubefix (Recommended Approach)

pytubefix is an actively maintained fork that addresses PyTube's API compatibility issues.

# Install the fixed library
pip install pytubefix

# Modified code using pytubefix
from pytubefix import YouTube

youtubeObject = YouTube('https://www.youtube.com/watch?v=DASMWPUFFP4')
youtubeObject = youtubeObject.streams.get_highest_resolution()
youtubeObject.download('D:\\Utakmice')

Key advantages:

• Drop-in replacement for PyTube (minimal code changes)
• Actively maintained with YouTube API updates
• Resolves the HTTP 400 error for long videos
• Preserves all PyTube functionality

Maintenance Note

This fork has addressed 15+ PyTube issues in 2024 alone. Check pytubefix on PyPI for updates.

2. Patch Original PyTube

Manually modify PyTube's innertube.py client configuration (temporary fix until update):

1. Locate innertube.py in your PyTube installation (typically in site-packages/pytube)
2. Find the following line:

def __init__(self, client='ANDROID', use_oauth=False, allow_cache=True):

3. Change to:

def __init__(self, client='WEB', use_oauth=False, allow_cache=True):

Pros/Cons:
✓ Quick fix without library change
✘ Requires re-patching after PyTube updates
✘ May break with future YouTube API changes

Version Warning

This fix applies to PyTube versions up to 15.0.0. Check GitHub Issue #1894 for latest patches.

3. Use yt-dlp Alternative

For future-proof downloading, consider yt-dlp—an actively maintained YouTube downloader:

# Installation
pip install yt-dlp

# Download implementation
import yt_dlp

def download_video(url):
    ydl_opts = {
        'outtmpl': 'D:/Utakmice/%(title)s.%(ext)s',  # Custom output path
        'format': 'bestvideo+bestaudio/best'         # Best resolution
    }
    with yt_dlp.YoutubeDL(ydl_opts) as ydl:
        ydl.download([url])

# Usage
download_video('https://www.youtube.com/watch?v=DASMWPUFFP4')

Benefits:

• Actively maintained (fixes within hours of YouTube changes)
• Supports advanced features (formats, metadata, error recovery)
• 300+ site integrations beyond YouTube
• More reliable for long/live videos

Problem Explanation

The HTTP 400 error occurs due to PyTube's outdated API request headers when interacting with YouTube's InnerTube API. YouTube periodically changes validation requirements, causing older clients like PyTube's default ANDROID credentials to be rejected. Long videos trigger additional validation checks that expose these outdated configurations.

Key technical details:

• PyTube sends requests with deprecated client parameters (client="ANDROID")
• YouTube returns 400 Bad Request for authentication mismatches
• Fixes involve updating client parameters (client="WEB") or library internals
• Alternative libraries like yt-dlp implement auto-updating client logic

Best Practices

1. Avoid modifying library source files
   Prefer maintained forks like pytubefix over manual patches for future stability

2. Add error recovery
   Implement retry logic for temporary network issues:

# Retry example
from pytubefix import YouTube
from urllib.error import HTTPError
import time

try:
    YouTube(url).streams.first().download()
except HTTPError as e:
    if e.code == 400:
        print("Retrying after API error...")
        time.sleep(5)
        # Add fallback logic here

3. Regularly update dependencies
   Monitor library update channels for compatibility fixes:

# Check for updates weekly
pip list --outdated

4. Verify video availability
   Test with multiple videos to rule out content-specific restrictions

Final Recommendation:
Migrate to pytubefix for minimal code changes combined with active maintenance. For new projects, consider yt-dlp for its robust feature set and faster issue resolution cycle. Monitor PyTube's GitHub issues for future core library updates.