Quick answer
To transcribe audio to text, upload your audio or video file to an AI transcription tool, wait for the AI to process the speech, and download the resulting transcript. The process works for MP3, MP4, M4A, WAV, MOV, FLAC, WebM, OGG, and most other common audio and video formats.
This guide covers what each format means for transcription quality, which formats work best for different recording sources, and how to get the cleanest transcript from any type of audio file.
Why format matters for audio transcription
Not all audio files are equal. The format, bitrate, and recording conditions determine how much detail the AI has to work with.
A 320kbps MP3 from a professional microphone will transcribe more accurately than a compressed voice memo from a laptop’s built-in mic — even if both are labeled “MP3.” Understanding what creates a high-quality audio file helps you get better results before you upload.
Two things that matter most:
- Audio quality at recording time — the microphone, environment, and recording settings
- File encoding — the format and compression applied when saving the file
AI transcription like Atter AI achieves 98.7% accuracy on clean audio. As audio quality decreases, accuracy decreases with it — regardless of the format.
Supported audio formats
| Format | Type | Common source | Transcription quality |
|---|---|---|---|
| MP3 | Compressed audio | Podcasts, voice recorders, phone calls | Good at 128kbps+; lower bitrates reduce accuracy |
| MP4 | Video container | Zoom, Teams, Meet recordings | Excellent; AI extracts audio track automatically |
| M4A | Apple audio (AAC) | iPhone Voice Memos, Zoom audio-only export | Excellent; efficient compression with high quality |
| WAV | Uncompressed audio | Professional recorders, audio interfaces | Best possible quality; large file sizes |
| MOV | Apple video container | iPhone camera, QuickTime, Mac screen recording | Excellent; same as MP4 for transcription |
| FLAC | Lossless compressed | High-fidelity recorders, archival recordings | Best quality with smaller files than WAV |
| WebM | Web video format | Browser recordings, Google Meet older exports | Good at typical web quality settings |
| OGG | Open compressed audio | Open-source recording apps, Linux tools | Good; similar to MP3 at equivalent bitrate |
| AAC | Compressed audio | Apple devices, streaming platforms | Good; generally better than MP3 at same bitrate |
| AMR | Phone call audio | Android call recordings, older voice recorders | Acceptable; narrow frequency range reduces accuracy |
Format-specific workflow: how to get the best transcript
MP4 (Zoom, Teams, Meet recordings)
MP4 is the most common format for meeting recordings. All major video conferencing platforms export in MP4.
Best workflow:
- End the meeting and let the recording save or export
- Download the MP4 file to your computer
- Upload to Atter AI — the AI automatically extracts the audio track
- Set speaker labels using the participant names from the call
Quality tip: Record meetings in the highest quality your platform supports. Zoom’s cloud recording offers 1080p video with stereo audio; use these settings if available.
Common issue: Some platforms compress recordings aggressively for cloud storage. Download the original file rather than relying on in-app playback for transcription.
MP3 (Podcasts, voice recorders, phone call exports)
MP3 is the most universal audio format. Almost every recording device and software can export MP3.
Best workflow:
- Export from your recording app or device as MP3 at 128kbps or higher
- Upload directly to Atter AI
- If the recording contains background noise, expect 5–8% lower accuracy compared to clean audio
Quality tip: For podcast interviews and research conversations, record at 192kbps or higher. The file size increase is modest, and accuracy improves noticeably on voices with distinct accents.
Common issue: Voice memos exported as MP3 from older Android apps are sometimes saved at 32kbps, which produces poor transcription results. Check the export settings in your recording app.
M4A (iPhone Voice Memos, Zoom audio-only)
M4A (AAC inside an MPEG-4 container) is the default format for iPhone Voice Memos and Zoom’s audio-only recording option.
Best workflow:
- Open the Voice Memos app on iPhone
- Swipe left on the recording and tap Share
- Choose “Save to Files” and pick a location you can access from your computer
- Upload the M4A file to Atter AI
For AirPods recordings: iPhone Voice Memos with AirPods Pro or AirPods (3rd gen) includes noise cancellation during recording, which improves transcription accuracy noticeably.
Quality tip: M4A files from iPhone typically record at 44.1kHz stereo, which is excellent quality. No special settings needed — the default produces great results.
WAV and FLAC (Professional and archival recordings)
WAV (uncompressed) and FLAC (lossless compressed) are the highest-quality audio formats. WAV files can be very large — a one-hour stereo recording at 44.1kHz/16-bit is approximately 600MB.
Best workflow:
- Export or receive the WAV/FLAC file from your recording system
- Upload directly to Atter AI
- Processing time may be slightly longer due to file size, but transcription quality is highest with these formats
Quality tip: If storage and upload speed are concerns, FLAC offers the same audio quality as WAV at roughly 50–60% of the file size.
Common issue: WAV files from some field recorders include metadata that causes playback issues in certain apps. Atter AI handles WAV uploads regardless of metadata issues.
MOV (iPhone video, Mac screen recording, QuickTime)
MOV is Apple’s video container format, used by iPhone camera, Mac screen recording, and QuickTime.
Best workflow:
- For iPhone video: transfer via AirDrop, USB, or iCloud to your computer
- For Mac screen recording: find the file in ~/Desktop or ~/Movies by default
- Upload the MOV file to Atter AI — audio is extracted automatically
Quality tip: If you are recording a presentation or tutorial for transcription, use the Mac’s built-in screen recorder (Shift+Command+5) with “Microphone” enabled for clear voice capture.
Common issue: Very long iPhone videos (2+ hours) can be several gigabytes. If upload is slow, use QuickTime to export an audio-only M4A version, which will upload and process faster.
WebM and OGG (Browser and open-source tools)
WebM is produced by browser-based recorders and some web meeting tools. OGG is common in Linux environments and open-source recording software.
Best workflow:
- Download the WebM or OGG file from wherever it was saved
- Upload to Atter AI — both formats are fully supported
- Review the transcript for accuracy, as these formats sometimes use variable bitrate encoding that can affect quality at low bitrate settings
Quality tip: If your recording tool gives you a quality or bitrate setting, use at least “medium” or “standard” rather than the lowest setting. Higher quality settings add minimal file size for speech recordings.
Phone call recordings (AMR, MP3, AAC)
Phone call recordings often have lower audio quality than video call recordings because phone networks compress voice audio heavily.
Expected accuracy: 93–96% for typical phone call audio (versus 98.7% for clean studio-quality audio). This is still far better than manual transcription.
Best workflow:
- Export the recording from your call recording app
- Check the format — most Android call recorders export as MP3 or AMR; most iPhone call recording apps export as M4A
- Upload to Atter AI
- Spend slightly more time on the review step for proper nouns and numbers
Quality tip: If you have a choice of recording format in your call app, choose MP3 or AAC over AMR. AMR was designed for voice calls with heavy compression, while MP3/AAC preserves more of the frequency range relevant to speech clarity.
The full audio-to-text workflow from file to final output
No matter the format, the complete workflow follows these five stages:
Stage 1: Prepare the file
- Check the file opens and plays correctly
- Note the approximate duration
- Identify how many speakers are in the recording
Stage 2: Upload to Atter AI
- Open Atter AI (app or web)
- Tap New Recording → Upload File
- Select your file and wait for the upload to complete
Stage 3: Let AI process
- Processing takes roughly 1 minute per 10 minutes of audio
- A 1-hour recording: ~5–7 minutes
- A 3-hour recording: ~15–20 minutes
Stage 4: Review the transcript Focus your review on:
- Speaker name accuracy (rename “Speaker 1” to real names)
- Numbers, dates, and deadlines
- Proper nouns: names, company names, product names
- Technical vocabulary in specialized fields (legal, medical, engineering)
Stage 5: Export and use Choose the output format that fits your workflow:
- Word (.docx) — for editing, sharing in document systems
- PDF — for formal records, client deliverables
- Plain text — for copying into other tools
- Shareable link — for teammates who want to search the transcript online
Atter AI: languages and pricing
Atter AI supports 90+ languages for audio transcription, including English, Mandarin, Cantonese, Japanese, Korean, Spanish, French, German, Portuguese, Arabic, Hindi, and more. There are no time limits on individual recordings or monthly usage.
Pricing:
- $129.99 one-time (lifetime plan)
- $49.99 per year (annual plan)
- $6.99 per week (weekly plan)
- 3-day free trial available
FAQ
What is the best audio format for AI transcription?
WAV and FLAC produce the highest-quality transcripts because they are lossless formats. For everyday use, M4A and high-bitrate MP3 (128kbps+) produce excellent results with much smaller file sizes. MP4 video files work equally well since the AI extracts the audio track automatically.
Can I transcribe a video file (MP4, MOV) without extracting audio first?
Yes. Atter AI accepts MP4, MOV, and other video formats directly. You do not need to extract audio before uploading — the AI does this automatically.
How large can the audio file be for transcription?
Atter AI accepts files of any size. Very large files (2GB+) may take longer to upload depending on your internet connection. For very long recordings, there is no processing time limit.
Does audio format affect transcription accuracy?
The format itself matters less than the audio quality within the file. A clean 128kbps MP3 will transcribe more accurately than a noisy WAV file. Format affects accuracy mainly when the bitrate is very low (below 64kbps for speech), which causes audio degradation that the AI cannot compensate for.
Can I transcribe a YouTube video or a URL directly?
Yes. Atter AI supports URL-based imports for YouTube videos and other supported online sources. Use the “Import from URL” option instead of uploading a file.
What languages can be transcribed?
Atter AI supports 90+ languages, including all major European languages, Asian languages (Mandarin, Cantonese, Japanese, Korean), Middle Eastern languages (Arabic, Hebrew), and South Asian languages (Hindi, Tamil, Bengali). Multilingual recordings with mixed languages are also supported.
How accurate is AI audio transcription?
Atter AI achieves 98.7% accuracy on clean audio. For phone call quality audio, expect 93–96%. For noisy or overlapping speech, expect 88–93%. Review important transcripts before using them for formal records.