# BUG: Audio files fail to play on AnkiMobile **URL:** \ **Category:** Help\ **Created:** [August 30, 2025, 1:46pm UTC](https://forums.ankiweb.net/t/bug-audio-files-fail-to-play-on-ankimobile/66190 "2025-08-30T13:46:24Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![swatson741](https://avatars.discourse-cdn.com/v4/letter/s/f4b2a3/32.png) [@swatson741](https://forums.ankiweb.net/u/swatson741)\ **Post date:** [August 30, 2025, 1:46pm UTC](https://forums.ankiweb.net/t/bug-audio-files-fail-to-play-on-ankimobile/66190/1 "2025-08-30T13:46:24Z")
Anki fails to play audio files from my flashcard set that work fine on the desktop app. The files come from my course notes, and they weren’t encoded by me. This is a file encoded by me, and works in AnkiMobile: ```bash swatson@Stevens-MBP ~ ❯ file -I /Users/swatson/Library/Application\ Support/Anki2/Steven/collection.media/unit_3.2_dovere_io_devo.m4a /Users/swatson/Library/Application Support/Anki2/Steven/collection.media/unit_3.2_dovere_io_devo.m4a: audio/x-m4a; charset=binary ``` `file` identifies a `audio/x-m4a; charset=binary` file. This file is _ **working** _ in AnkiMobile. ```bash swatson@Stevens-MBP ~ ❯ file -I /Users/swatson/Library/Application\ Support/Anki2/Steven/collection.media/unit_3.2_5.m4a /Users/swatson/Library/Application Support/Anki2/Steven/collection.media/unit_3.2_5.m4a: video/quicktime; charset=binary ``` `file` identifies a `video/quicktime; charset=binary` file. This file is _ **not working** _ in AnkiMobile. ---
**Author:** ![swatson741](https://avatars.discourse-cdn.com/v4/letter/s/f4b2a3/32.png) [@swatson741](https://forums.ankiweb.net/u/swatson741)\ **Post date:** [August 30, 2025, 7:06pm UTC](https://forums.ankiweb.net/t/bug-audio-files-fail-to-play-on-ankimobile/66190/2 "2025-08-30T19:06:13Z")
It’s worth noting that for now all the files can be made to work by running the following, ```bash for i in *.m4a; do afconvert -f m4af -d aac "$i" -o "$i"; done ``` in the directory containing the audio files on macintosh. ---
**Author:** ![BenJamesBen](https://avatars.discourse-cdn.com/v4/letter/b/13edae/32.png) [@BenJamesBen](https://forums.ankiweb.net/u/BenJamesBen)\ **Post date:** [August 30, 2025, 8:49pm UTC](https://forums.ankiweb.net/t/bug-audio-files-fail-to-play-on-ankimobile/66190/3 "2025-08-30T20:49:56Z")
From what you posted, it appears that the `unit_3.2_5.m4a` file might be a QuickTime video file improperly named with an `.m4a` extension? 1. I created a QuickTime video file named `test.mov`, then copied it to `test.m4a`. ```sh % file -I test.m4a test.m4a: video/quicktime; charset=binary ``` 1. I then added `test.mov` and `test.m4a` to an Anki note. 2. In Mac desktop Anki app, when browsing and previewing the note’s cards, both files autoplay. (A window appears, the video plays in the window, and then the window disappears. This happens for both files in sequence. Also, play buttons are seen on the card.) 3. In iPhone AnkiMobile app, when browsing and previewing the note’s cards, the `.mov` file appears and autoplays. (The video apppears on the card and autoplays. The video has media control buttons, including a play button.) However, the `.m4a` file does not play. (A play button appears on the card, but pressing the button results in an error dialog.) ```plaintext Error playing audio. This can be caused by a corrupt file, a file iOS does not support (eg. ogg), or an mp3 file incorrectly named .wav test.m4a: Error Domain=NSOSStatus-ErrorDomain Code=1954115647 "(null)" ``` I suggest that you try some testing: Rename your `unit_3.2_5.m4a` file to `unit_3.2_5.mov` and also change it on a corresponding Anki card. See if Anki behaves differently with the renamed file. (If the problem is a misnamed file, then I’m not sure if this would be considered a bug, strictly-speaking? I’m not sure if AnkiMobile has an obligation to handle misnamed media files even if desktop Anki is able to do so?) ---
**Author:** ![swatson741](https://avatars.discourse-cdn.com/v4/letter/s/f4b2a3/32.png) [@swatson741](https://forums.ankiweb.net/u/swatson741)\ **Post date:** [August 31, 2025, 2:13pm UTC](https://forums.ankiweb.net/t/bug-audio-files-fail-to-play-on-ankimobile/66190/4 "2025-08-31T14:13:37Z")
This is basically a bug. I believe the files are old, and they use an encoding scheme that existed before m4a which is to make an mp4 with no video data. It’s a valid encoding, and it basically works everywhere except for ios (and maybe android???). But, the fact is that this creates a parity error between these platforms. And, right now, Anki (the app) does nothing and gives you no option. It doesn’t warn you. It doesn’t make a suggestion. It doesn’t convert the files for you. It only gives a generic error toast when and if it fails. ---
**Author:** ![Danika\_Dakika](https://sea2.discourse-cdn.com/flex002/user_avatar/forums.ankiweb.net/danika_dakika/32/17815_2.png) [@Danika\_Dakika](https://forums.ankiweb.net/u/Danika_Dakika)\ **Post date:** [August 31, 2025, 11:55pm UTC](https://forums.ankiweb.net/t/bug-audio-files-fail-to-play-on-ankimobile/66190/5 "2025-08-31T23:55:53Z")
> [@swatson741](#): > > This is basically a bug. AnkiMobile relies on iOS functionality to play media. If iOS doesn’t support the filetype, then you won’t be able to use it in AnkiMobile. This can’t be fixed in the app – you’ll have to fix the files themselves. > [@Sound not playing on iOS](https://forums.ankiweb.net/t/sound-not-playing-on-ios/41132/15): > > It appears to be a common problem with the add-on: [Some mp3 audio files don't work in iOS Anki but work on macOS](https://forums.ankiweb.net/t/some-mp3-audio-files-dont-work-in-ios-anki-but-work-on-macos/36743) This app can tell you what format a file is in: [MediaInfo](https://mediaarea.net/en/MediaInfo/). But converting files can be somewhat complicated if you’re not so familiar with computers, so you may find it easier to add audio to your cards using some other method (a different add-on, the built-in [TTS support](https://faqs.ankiweb.net/text-to-speech-support.html), etc. ---
**Author:** ![system](https://us1.discourse-cdn.com/flex002/uploads/anki2/original/1X/8f1279ababc5879d54e4838989f606cfe55af8c7.jpeg) [@system](https://forums.ankiweb.net/u/system)\ **Post date:** [September 30, 2025, 11:56pm UTC](https://forums.ankiweb.net/t/bug-audio-files-fail-to-play-on-ankimobile/66190/6 "2025-09-30T23:56:42Z")
Closed on September 30, 2025, 11:56pm UTC This topic was automatically closed 30 days after the last reply. New replies are no longer allowed.