FileFix

Repair a corrupted M4A file that won't play.

Upload an M4A that won't open or play. We rebuild the file and let you hear a free preview clip. Pay only if it worked.

Drop a broken audio file here — the free preview shows what's recoverable before you pay.

Files up to 2 GB.

Free preview — pay only if you download ($8)

Your files auto-delete — delete them sooner anytime

No person looks at your file as part of repair

Uploading your file.

Keep this tab open while the file transfers. Large files can take a few minutes.

Starting upload...

Recovering what we can.

Analyzing your file...

Here's what we recovered.

Review the watermarked preview before checkout. It is 12 seconds sampled from the start, middle and end of your recording.

Your files auto-delete — delete them sooner anytime

No person looks at your file as part of repair

Repair your file

Choose a supported file to see what can be repaired before checkout.

You preview before you pay. If the download is materially worse than the preview you approved, we'll refund you.

Try another file

Good news — your file isn't damaged. No charge.

There's nothing to repair. If it still looks broken, the issue may be the player, codec, or viewer on your device rather than the file itself.

We couldn't recover this one.

The file is too damaged to rebuild, so there is nothing to preview and no charge.

Unrepaired files are kept encrypted for up to 30 days, then deleted.

FileFix can't fix that kind of file yet.

Right now we repair video, audio, document, and image files (MP4, MOV, M4V, MKV, AVI, TS, MTS, M2TS, MPG, MPEG, VOB, 3GP, WebM, FLV, M4A, WAV, MP3, AAC, FLAC, OGG, AIFF, XLSX, DOCX, PPTX, ODT, ZIP, PDF, AI, HEIC, and HEIF). We're adding support for more formats over time.

We store just your email and the file type — never the file itself. One message, when it's ready. No spam.

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Why M4A files won't play

M4A is what phones and laptops write for voice memos, recorded calls, and AAC music — an MP4 container wrapped around AAC audio. Most "corrupted M4A" problems are damage to that container: the moov atom that indexes where the audio is and how long it runs got damaged or was never written, which is exactly what an interrupted recording or a crashed app leaves behind.

Before any repair, check whether a cleaner copy of the recording already exists. An iPhone voice memo may still be in the Voice Memos app's Recently Deleted folder or synced to another device through iCloud; a recording shared over chat or email may be complete at the sender's end even if your copy was cut off in transfer. A clean original beats any rebuild, because repair can only work with the audio bytes that are actually in the file.

Trying a different player is also free and worth a minute: open the file in VLC or on another device to rule out a player-specific quirk. When every player refuses the same file, the container itself is damaged. What generally does not help is a format converter — an "M4A to MP3" tool has to read the file first, which is exactly the step that fails, so it stops with the same error the player showed.

When the container index is missing, a player can't find the audio and shows an error or plays nothing — even though the AAC audio inside is often intact. FileFix reads what's actually in the file, rebuilds the container index, and re-assembles a playable file. You hear a free watermarked preview clip and see how much we recovered before paying.

This works for many container and index problems in M4A files. It can't rebuild a file that never captured any audio.

What we can and can't fix

We can usually fix

  • M4A voice memos, recorded calls, and AAC music files that won't open or play after an interrupted save.

We can't fix

  • Genuinely empty files, deleted files, or DRM-protected tracks from a music store. More →

How it works

  1. Upload Drop a supported audio file in. It uploads over an encrypted connection. The repair runs automatically — no person listens to your file.
  2. Free Watermarked Preview You hear a free watermarked preview clip and see exactly how much we recovered.
  3. Pay & Download If it's right, you pay $8 once and download a clean, full-quality audio file.

About half of real-world corrupted files repair fully; you always preview first.

See what's recoverable.

Free preview · pay only if it worked · private & auto-deleted

Upload your audio file

Questions