YouTube to MP3 Converter

This tool provides a domain-appropriate solution for extracting audio from YouTube videos and encoding it as MP3 or other audio formats. It targets educators, content creators, researchers, language learners, and casual listeners who need a portable audio track without video. Assumed intent is offline listening and library integration, not a replacement for licensed distribution.
Core Logic & Features include URL validation, video accessibility check, audio extraction from permitted streams, encoding to MP3 by default with bitrate options (128/192/320 kbps), optional AAC/M4A support, metadata embedding, and sanitized output naming. Optional/advanced features include batch processing, queue management, and metadata templates.
Inputs & Outputs cover video_url (required), format (default mp3), bitrate_kbps (128/192/320; default 192), output_filename (optional), embed_metadata (default true); outputs include audio_url, duration_seconds, size_mb_estimate.
Algorithms & Calculations apply size_estimate: size_mb ≈ duration_seconds * bitrate_kbps / 8 / 1024; duration from video metadata; encoding overhead considered.
Error & Edge Cases address invalid URLs, regional or age restrictions, content rights issues, encoding failures, and network problems with descriptive error codes.
Industry/Region & Localization uses kbps and MB; supports Unicode metadata; conforms to standard audio formats and YouTube access norms.
Assumptions & Exclusions assume rights to source content; excludes DRM bypass; batch processing may be tiered; audio-only outputs; no UI guidance included.