Convert M4A to AAC

Choose your M4A file and get a AAC file in seconds. Nothing leaves your device.

Converter

  • FilesOne or many, images and videos mixed
  • FolderEvery matching file inside, subfolders included
  • ArchiveZIP, RAR, 7z or TAR: convert the contents or the archive itself

Drop files, folders or archives here

Unsupported files are skipped. Nothing is uploaded.

Everything runs in your browser. Files are not uploaded.

About this conversion

Only the audio encoding changes: the recording is decoded and encoded again in your browser.

Good to know

Recompressing a lossy file costs a little more quality.

Raw AAC files carry no tags and seek poorly; M4A is the better choice for music libraries.

How it works

The audio is converted by ffmpeg compiled to WebAssembly. It loads only when you choose a file and runs in a background thread.

Your browser can

  • Built-in image codecs
  • Hardware video (WebCodecs)
  • Multiple threads
  • Create AVIF natively

If something is missing, the conversion takes a little longer but still works.

About M4A (MPEG-4 Audio, usually AAC)

M4A is the MP4 container holding only audio, usually AAC, and the default format of iTunes and Apple Music.

  • iTunes and Apple Music libraries
  • Voice memos on iPhone
  • Audiobooks (as M4B)

M4A (MPEG-4 Audio, usually AAC) →

About AAC (Advanced Audio Coding, raw ADTS stream)

A .aac file is a raw AAC audio stream without a container, the codec behind M4A, YouTube and most streaming services.

  • Efficient codec with good quality at low bitrates
  • Widely supported by hardware decoders
  • Simple stream, easy to cut

AAC (Advanced Audio Coding, raw ADTS stream) →

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Frequently asked questions

Are my files uploaded to a server?

No. The conversion runs entirely in your browser with local code. Your files never leave your device, and there is no upload.

Is there a file size limit?

There is no limit on our side, but your browser memory is. Images work for very large files; for videos, files above a few hundred megabytes can fail on devices with little memory.

Will the quality suffer?

That depends on the target format and settings. Use the quality option to balance size and detail; lossless targets keep everything the source contained.

Which browsers are supported?

Current versions of Chrome, Edge, Firefox and Safari. Fast hardware paths are used where available, with a compatible fallback otherwise.