X AAC Encoder 1.2

X AAC Encoder is a free Windows front end for FAAC, the open-source AAC encoder, built for the jobs that are tedious from a command line.

Version 1.2 moves it onto FAAC 2.2 and adds HE-AAC, which makes a real difference to voice and podcasts at low bitrates.

It costs nothing, shows no ads, needs no account and has no installer - you unzip it and run it.

What Changed in 1.2

• FAAC 2.2 inside. The retuned encoder is faster than the one earlier versions shipped, and sharper on transients such as drum hits and plucked strings.
• HE-AAC v1 encoding. Much better sound at 16 to 64 kbps, which is the range where voice recordings, podcasts and internet radio streams live.
• CBR and a peak cap. A true constant-bitrate mode for streaming servers that insist on one, plus a ceiling on how high any single frame can go.
• Mixed joint stereo. A new stereo mode joins the existing Joint, Mid/Side and Intensity options.
• Retuned presets. New HE-AAC presets for voice and podcasts, and the VBR presets recalibrated for FAAC 2.2.
• It remembers you. Your settings survive a restart, and the app detects which FAAC version it has been pointed at.

Which Download to Pick

There are two files, and most people want the first one.

• The portable package. The app plus FAAC 2.2 and FFmpeg, ready to run from any folder or a USB stick.
• The app on its own. Just X-AAC-Encoder.exe, for people who already keep FAAC 2.2 and FFmpeg elsewhere and want to point it at their own copies.

Version 1.2 needs 64-bit Windows 10 or 11. Earlier versions also ran on Windows 7 and on 32-bit systems, but FAAC 2.2 is only built for 64-bit Windows, so that support ended here.

What You Can Do With It

• Batch encode whole folders. Drop in a file, a selection or a folder tree, and each file gets its own progress bar - cancelling leaves no half-encoded files behind.
• Feed it almost anything. FAAC itself only reads WAV, so the bundled FFmpeg decodes MP3, FLAC, OGG, Opus, WMA, APE, WavPack, AIFF and the audio inside MP4, MKV, AVI, MOV, WebM and TS files on the fly.
• Tag as you go. Title, artist, album, track and disc numbers, genre and cover art go straight into the M4A file - and with "Copy tags from source" on, a tagged FLAC library keeps its tags and artwork automatically.
• Choose VBR, ABR or CBR. VBR quality runs from 10 to 1000, and ABR or CBR from 16 to 320 kbps.
• Let it name the files. Filename templates accept {artist}, {album}, {title} and {stem}, and name clashes are skipped, overwritten or auto-numbered.
• See the exact command. A live preview shows the faac.exe command with every flag filled in - handy for learning the options, or for pasting into a script later.

Picking a Profile and a Bitrate

For music at 128 kbps and above, plain AAC-LC is the right choice and needs no further thought. Below about 64 kbps, switch to HE-AAC, which stores the high frequencies as a compact description and rebuilds them on playback, so voice and podcasts stay clear at a fraction of the size.

FAAC 2.2 writes HE-AAC v1 but not v2, the variant that also squeezes the stereo image for the very lowest bitrates. For that, the FDK AAC Codec is the tool, and our guide to AAC vs AAC-LC vs AAC-HE explains the differences.

Save as .m4a unless something specifically asks for raw AAC. M4A carries tags and cover art and plays on phones, in iTunes and in virtually every player, while a raw .aac stream carries no tags at all.

Where It Fits Among the Other Audio Tools

It does one job, AAC and M4A, and it does it without iTunes. Apple's encoder through qaac needs Apple's audio libraries installed, and Nero AAC Codec has not been developed for years.

If AAC is not actually what you need, pick by the job instead.

• MP3 files. LAME MP3 Encoder is the reference encoder, and LameXP wraps it with several others in one batch converter.
• A step-by-step wizard. winLAME walks you through MP3, Ogg Vorbis, Opus and FLAC one screen at a time.
• MP3 with a simpler window. X Audio Converter is the lighter sibling from the same family.
• Voice at the lowest bitrates. Opus Audio Codec beats AAC below 96 kbps, as long as the device that plays the file supports it.
• A one-off file with nothing installed. Our browser-based Audio Converter handles a single conversion on the spot.

For playing AAC back rather than making it, the FAAD2 half of the FAAD2 and FAAC bundle is the open-source reference decoder. The AAC ACM Codec wraps it for older programs such as VirtualDub.

To confirm what actually ended up in a finished file, Codec Finder reads the codec and profile straight from it.

Who Should Look Elsewhere

• Your PC runs Windows 7, 8 or a 32-bit edition. Version 1.2 will not start - Settings, System, About shows the system type if you are not sure.
• You need HE-AAC v2 for very low-bitrate stereo. FAAC does not write it, so take FDK AAC instead.
• You already script faac.exe and never touch tags. The command line does everything the encoder can, and a window adds nothing for you.

Quick questions

The full feature list and screenshots are on the X AAC Encoder page at xcodecpack.com.

Download X AAC Encoder 1.2 and see how it handles your library, or tell us how you got on if you have used it before.