Overview yt-dlp can convert downloaded media to different formats using ffmpeg. This includes remuxing (changing container without re-encoding) and transcoding (re-encoding to a different codec).
Remuxing is faster and maintains quality, while transcoding allows codec changes but may reduce quality.
Remuxing Videos Remux changes the container format without re-encoding the video/audio streams:
# Remux to MP4 if needed yt-dlp --remux-video mp4 URL # Remux to MKV yt-dlp --remux-video mkv URL # Remux to WebM yt-dlp --remux-video webm URL
Video : mp4, mkv, webm, flv, avi, mov, gifAudio : m4a, aac, mp3, opus, ogg, flac, wav, alac, mka, aiff
Conditional Remuxing Use rules to remux specific formats:
Single Rule
Multiple Rules
Chain Rules
# Remux AAC files to M4A yt-dlp --remux-video "aac>m4a" URL
Re-encoding Videos Re-encoding reduces quality and takes much longer than remuxing. Use only when necessary.
Transcode videos to different codecs:
# Re-encode to MP4 (if necessary) yt-dlp --recode-video mp4 URL # Re-encode to WebM yt-dlp --recode-video webm URL # Conditional re-encoding with same syntax as remux yt-dlp --recode-video "avi>mp4/flv>mp4/mp4" URL
Extract and convert audio
Basic extraction
# Extract audio in best format yt-dlp -x URL
Convert to specific format
# Convert to MP3 yt-dlp -x --audio-format mp3 URL # Convert to AAC yt-dlp -x --audio-format aac URL # Convert to FLAC (lossless) yt-dlp -x --audio-format flac URL
Set audio quality
# VBR quality (0=best, 10=worst) yt-dlp -x --audio-format mp3 --audio-quality 0 URL # Specific bitrate yt-dlp -x --audio-format mp3 --audio-quality 320K URL
Conditional audio conversion # Convert opus to mp3, keep others as best yt-dlp -x --audio-format "opus>mp3/best" URL
Combine format selection with conversion for precise control:
Best Quality MP4
Specific Codecs
With Remux
# Download best video+audio and merge to MP4 yt-dlp -f "bv*+ba" --merge-output-format mp4 URL
yt-dlp includes useful presets:
MP4 Preset # Equivalent to: # --merge-output-format mp4 --remux-video mp4 # -S vcodec:h264,lang,quality,res,fps,hdr:12,acodec:aac yt-dlp -t mp4 URL
This preset:
Sets output to MP4 container
Prefers H.264 video codec
Prefers AAC audio codec
Optimizes for compatibility
MKV Preset # Equivalent to: # --merge-output-format mkv --remux-video mkv yt-dlp -t mkv URL
Converting Existing Files Convert already downloaded videos:
Download metadata
# First download with metadata yt-dlp --write-info-json URL
Re-process the file
# Process using saved info.json yt-dlp --load-info-json video.info.json \ --remux-video mp4
Convert subtitle formats:
# Convert subtitles to SRT yt-dlp --write-subs --convert-subs srt URL # Convert to VTT yt-dlp --write-subs --convert-subs vtt URL # Convert to ASS yt-dlp --write-subs --convert-subs ass URL # Disable conversion (keep original) yt-dlp --write-subs --convert-subs none URL
Convert thumbnail images:
# Convert thumbnails to JPG yt-dlp --write-thumbnail --convert-thumbnails jpg URL # Convert to PNG yt-dlp --write-thumbnail --convert-thumbnails png URL # Convert to WebP yt-dlp --write-thumbnail --convert-thumbnails webp URL # Multiple rules (similar to remux-video) yt-dlp --write-thumbnail --convert-thumbnails "webp>jpg/png" URL
Advanced Conversion Scenarios Encode for specific devices Apple Devices
Android Devices
Web Streaming
# H.264 + AAC in MP4 (maximum compatibility) yt-dlp -f "bv*[vcodec^=avc]+ba[acodec^=mp4a]" \ --merge-output-format mp4 \ --ppa "ffmpeg:-c:v libx264 -c:a aac" \ URL
Compress video Re-encoding will reduce quality. Always keep original files when compressing.
# Download and compress yt-dlp URL \ --recode-video mp4 \ --ppa "ffmpeg:-c:v libx264 -crf 23 -c:a aac -b:a 128k"
Convert with custom ffmpeg options # Custom video encoding yt-dlp URL \ --recode-video mp4 \ --ppa "ffmpeg:-c:v libx264 -preset slow -crf 18" # Custom audio encoding yt-dlp -x --audio-format mp3 \ --ppa "ffmpeg:-q:a 0" \ URL
Merge Multiple Streams Merge video and audio while converting:
# Download best video and audio, merge to MP4 yt-dlp -f "bv+ba" \ --merge-output-format mp4 \ URL # Merge specific formats yt-dlp -f "137+140" \ --merge-output-format mp4 \ URL
Merge with multiple audio tracks # Enable audio multistreams and merge yt-dlp -f "bv*+ba+ba.2" \ --audio-multistreams \ --merge-output-format mkv \ URL
Fixup Options Automatically fix common format issues:
# Auto-detect and fix file issues yt-dlp --fixup detect_or_warn URL # Force fixing yt-dlp --fixup force URL # Never fix yt-dlp --fixup never URL
Common Conversion Workflows Maximum compatibility # MP4 with H.264 and AAC (plays everywhere) yt-dlp -t mp4 -S "vcodec:h264,acodec:aac" URL
Archival quality # Best quality in MKV container yt-dlp -f "bv*+ba" --merge-output-format mkv \ --embed-metadata --embed-subs --embed-thumbnail \ URL
Space-efficient # Good quality, smaller file size yt-dlp --recode-video mp4 \ --ppa "ffmpeg:-c:v libx264 -crf 23 -c:a aac -b:a 128k" \ URL
Audio for music players # High quality M4A with metadata yt-dlp -x --audio-format m4a --audio-quality 256K \ --embed-metadata --embed-thumbnail \ URL
Troubleshooting Conversion fails # Check ffmpeg version ffmpeg -version # Try remuxing instead of re-encoding yt-dlp --remux-video mp4 URL # Check if format supports the codec yt-dlp --list-formats URL
Container doesn’t support codec # Use compatible container (MKV supports almost everything) yt-dlp --merge-output-format mkv URL # Or re-encode to compatible codec yt-dlp --recode-video mp4 URL
Quality loss Always prefer remuxing over re-encoding when you only need to change the container format.
# Use remux instead of recode yt-dlp --remux-video mp4 URL # Good yt-dlp --recode-video mp4 URL # Avoid if possible
Next Steps
Post-Processing Learn about all post-processing options
Audio Extraction Detailed audio extraction guide
Format Selection Advanced format selection reference
Post-Processor Arguments ffmpeg and post-processor arguments