AAC to OGG Converter

Generate the exact FFmpeg command to convert AAC audio to OGG Vorbis at any quality level, and estimate the output file size before you run it.

File Details

Enter your file name and duration to generate the FFmpeg command and estimate the output size.

Also accepts .m4a, .mp4, or any AAC-containing container.

hrs

min

sec

FFmpeg Command Generator 

ffmpeg -i "input.aac" -c:a libvorbis -q:a 4 -map_metadata 0 "input.ogg"

Install FFmpeg free at ffmpeg.org. Run this command in your terminal after replacing the file name.

Batch convert AAC files (Linux / macOS)

for f in *.aac; do ffmpeg -i "$f" -c:a libvorbis -q:a 4 -map_metadata 0 "${f%.aac}.ogg"; done

Batch convert M4A files (Linux / macOS)

for f in *.m4a; do ffmpeg -i "$f" -c:a libvorbis -q:a 4 -map_metadata 0 "${f%.m4a}.ogg"; done

GUI alternatives

  • fre:ac — free, open-source audio converter, Windows / macOS / Linux, supports OGG Vorbis output
  • Audacity — free multi-track editor; open AAC, export as OGG Vorbis natively
  • VLC — free media player with a built-in transcode / convert menu supporting OGG output
  • Handbrake — free video/audio transcoder; use the audio-only passthrough or re-encode to OGG
Output File Size Estimator

Based on the duration you entered above. OGG Vorbis is variable bitrate — estimates use typical average bitrate per quality level.

Q1 (~80 kbps)

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Q3 (~112 kbps)

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Q4 (~128 kbps)

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Q6 (~192 kbps)

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Q8 (~256 kbps)

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Q10 (~500 kbps)

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Duration: 3 min 30 sec (210 s)

Why No In-Browser Conversion?

Browsers expose the Web Audio API for decoding audio, but they do not include a libvorbis encoder. Encoding OGG Vorbis requires the libvorbis native library. FFmpeg bundles libvorbis and handles the full pipeline:

  1. 1 FFmpeg opens the AAC or M4A container and reads the compressed audio stream.
  2. 2 The AAC codec decodes the stream to raw PCM (uncompressed) audio in memory.
  3. 3 libvorbis re-encodes the PCM data to OGG Vorbis at the quality level you specify.
  4. 4 FFmpeg writes the final OGG file to disk with Vorbis comment metadata preserved.

Install FFmpeg at ffmpeg.org (free, open-source). Most Linux distributions offer it via their package manager: sudo apt install ffmpeg or brew install ffmpeg.

OGG Vorbis Quality Reference

Quality Avg. Bitrate Size / min Best For
Q1 ~80 kbps ~0.6 MB Voice, speech, podcasts
Q3 ~112 kbps ~0.8 MB Casual listening
Q4 ~128 kbps ~0.96 MB General music listening
Q6 ~192 kbps ~1.4 MB High quality music
Q8 ~256 kbps ~1.9 MB Audiophile, quality headphones
Q10 ~500 kbps ~3.75 MB Maximum quality, archival OGG

AAC vs. OGG Vorbis — At a Glance

AAC (Advanced Audio Coding)

  • Excellent quality at low bitrates; default for Apple and YouTube
  • Natively supported on iOS, macOS, Android, and most smart TVs
  • Proprietary codec; patent-encumbered in some jurisdictions
  • Not preferred for open-source or open-content platforms

OGG Vorbis

  • Open, royalty-free codec — no patent restrictions
  • Preferred for Linux, open-source games (Godot, Pygame), and Wikipedia
  • Not natively supported on iOS or some older hardware
  • Slightly lower compression efficiency than AAC at equivalent quality
Copied!

Summary

Generate the exact FFmpeg command to convert AAC audio to OGG Vorbis at any quality level, and estimate the output file size before you run it.

How it works

  1. Enter your AAC file name and its duration in the form below.
  2. Choose a target OGG Vorbis quality level — lower values produce smaller files, higher values retain more detail.
  3. Optionally enable the -map_metadata flag to carry ID3/Vorbis comment tags from the AAC source.
  4. Copy the generated FFmpeg command.
  5. Open a terminal, paste the command, and run it — FFmpeg decodes the AAC and re-encodes using the libvorbis encoder.
  6. Play the output OGG to verify quality before deleting your original AAC file.

Use cases

  • Convert Apple Music or iTunes AAC downloads to OGG Vorbis for Linux music players.
  • Prepare audio assets for open-source games or game engines such as Godot that prefer OGG.
  • Replace proprietary AAC tracks with royalty-free OGG files for web or open-content projects.
  • Reduce file sizes when distributing audio to platforms that support OGG natively.
  • Batch-convert an entire AAC music library to OGG using a shell loop.
  • Estimate the output OGG file size at different quality levels before committing to a large batch.
  • Generate a ready-to-paste FFmpeg command without memorizing its flags.
  • Provide OGG versions of podcast episodes for listeners using open-source players.

Frequently Asked Questions

Last updated: 2026-06-09 · Reviewed by Nham Vu