HCOM to AAC Converter
Processing entirely on your device — large files may take a moment.
HCOM is the Sound Tools compressor format from the late 1980s Mac — FIR-decimated delta-modulation samples that almost nothing modern reads. AAC is the sweet spot when you want modern compression in an open, non-Apple container.
Because the whole conversion happens on your device, it is instant, unlimited and genuinely private — no accounts, no watermarks, no files on anyone's server. Multiple files are converted in one go.
How HCOM compares to AAC
| HCOM | AAC | |
|---|---|---|
| Compatibility | ffmpeg, archive tools | Streaming/broadcast standard |
| Best for | Rescuing legacy audio | Streaming and mobile audio |
How to convert HCOM to AAC
- 1
Select your files
Drag & drop your HCOM files onto the area above, or click to browse. You can add multiple files at once for batch conversion.
- 2
Convert instantly
Click "Convert to AAC". The conversion runs entirely inside your browser using WebAssembly — no upload, no queue, no waiting.
- 3
Download results
Download each converted AAC file individually, or grab everything at once as a ZIP archive.
About the HCOM format
HCOM is the Sound Tools compressor format from the late 1980s Mac — FIR-decimated delta-modulation samples that almost nothing modern reads.
ffmpeg decodes it natively inside your browser — the audio track is re-encoded to your chosen format with nothing ever uploaded.
+ Strengths
- ✓Decoded natively by ffmpeg
- ✓Runs entirely in your browser
- ✓Free, private, no watermarks
! Limitations
- −Legacy niche format
- −Modern tools rarely open it
- −Keep the original for archival round-trips
About the AAC format
AAC (Advanced Audio Coding) is MP3's official successor, standardized in MPEG-2 and MPEG-4 and refined over two decades. It is the audio track of YouTube, iPhone voice memos, digital radio and HE-AAC streaming — arguably the most-played codec in history. Files appear either raw (.aac, ADTS stream) or inside M4A/MP4 containers.
Its claim to fame is low-bitrate performance: HE-AAC v1/v2 keep speech and music listenable at 24–64 kbps, where MP3 collapses. Raw .aac streams carry weaker tagging than the M4A container, which is why music libraries prefer M4A even when the codec is identical.
+ Strengths
- ✓The standard of streaming, mobile and broadcast
- ✓Excellent low-bitrate behavior (HE-AAC)
- ✓Better than MP3 at equal bitrate
! Limitations
- −Raw .aac files tag poorly
- −Flavor fragmentation (LC/HE/xHE) confuses tooling
Why convert HCOM to AAC?
Converting makes sense where the strengths of AAC meet what HCOM cannot give you. The standard of streaming, mobile and broadcast Meanwhile Legacy niche format One pass through the converter above puts your file on the right side of that trade-off.
Frequently asked questions
Is this HCOM to AAC converter really free?
Yes — completely free, with no sign-up, no watermark and no daily conversion limits. The site is supported by advertising.
Are my files uploaded to a server?
No. The conversion runs entirely inside your browser using WebAssembly, so your files never leave your device — that is what makes it instant and private.
Does it work on Windows, Mac, iPhone and Android?
Yes. Anything with a modern browser works: Windows, macOS, Linux, Android and iOS. No software installation is required.
Is there a file size limit for HCOM to AAC?
The only limit is your device's memory, since nothing is uploaded. Files up to a few hundred megabytes work fine on a modern desktop browser; very large files simply take a little longer.
Are tags like title and artist preserved?
Tag handling varies between target formats and this conversion focuses on the audio itself. For archival copies where tags matter, keep the original file; the converted copy is for playback and sharing.
Will converting HCOM to AAC reduce audio quality?
If AAC is lossless, the output contains everything the HCOM file contains — no further loss is added. If AAC is lossy, one recompression pass is unavoidable; the quality slider controls how much. Loss that already happened in the source file can never be undone by converting.