---
title: "What file formats and size limits does ScribeSTT support?"
description: "The 12 supported audio and video extensions, the 1 GB per-file and 20-file-per-upload limits, and how video files are handled"
canonical_url: "https://docs.ardge.com/en/knowledge/scribestt/formats-and-limits"
---
# What file formats and size limits does ScribeSTT support?

> The 12 supported audio and video extensions, the 1 GB per-file and 20-file-per-upload limits, and how video files are handled

## Short answer

ScribeSTT supports 12 audio and video extensions, with a 1 GB cap per file and up to 20 files per upload in the web interface. There is no limit on audio length.

## Details

### Supported extensions

<table>
<thead>
  <tr>
    <th>
      Type
    </th>
    
    <th>
      Extensions
    </th>
  </tr>
</thead>

<tbody>
  <tr>
    <td>
      Audio
    </td>
    
    <td>
      <code>
        mp3
      </code>
      
      , <code>
        wav
      </code>
      
      , <code>
        ogg
      </code>
      
      , <code>
        flac
      </code>
      
      , <code>
        wma
      </code>
      
      , <code>
        opus
      </code>
    </td>
  </tr>
  
  <tr>
    <td>
      Video
    </td>
    
    <td>
      <code>
        mp4
      </code>
      
      , <code>
        webm
      </code>
      
      , <code>
        avi
      </code>
      
      , <code>
        flv
      </code>
      
      , <code>
        wmv
      </code>
      
      , <code>
        3gp
      </code>
    </td>
  </tr>
</tbody>
</table>

This list is the system's only criterion, and it applies in three places: web uploads, CLI uploads, and the filter a batch task uses when scanning a source folder. A file outside the list is reported as "Unsupported file format" on upload; during a batch scan it's simply skipped, with no record created.

### Size and count limits

<table>
<thead>
  <tr>
    <th>
      Limit
    </th>
    
    <th>
      Value
    </th>
    
    <th>
      Where it applies
    </th>
  </tr>
</thead>

<tbody>
  <tr>
    <td>
      Per-file size
    </td>
    
    <td>
      1 GB
    </td>
    
    <td>
      Web and CLI uploads
    </td>
  </tr>
  
  <tr>
    <td>
      Files per submission
    </td>
    
    <td>
      20
    </td>
    
    <td>
      The <strong>
        Create new transcription
      </strong>
      
       dialog in the web interface
    </td>
  </tr>
  
  <tr>
    <td>
      Audio length
    </td>
    
    <td>
      No limit
    </td>
    
    <td>
      Everywhere
    </td>
  </tr>
</tbody>
</table>

The 20-file limit is the web interface's per-upload cap, not a batch task's. How many files a batch task handles in one go depends on the source folder's contents and the task's **Scan depth** setting.

### How video files are handled

Only a video file's audio track is transcribed — nothing in the picture is recognized. A video file without an audio track therefore can't be transcribed: the record fails with "This file has no transcribable audio". When the file itself is damaged, it shows "The audio file couldn't be decoded — it may be corrupt".

## How to check

The web interface validates before you submit, so you don't have to upload and wait for a result:

1. Go to the **Transcriptions** page and click **New**
2. Select or drag files in the **Create new transcription** dialog

Files that don't qualify stay in the list outlined in red, showing "Unsupported file format. Accepted: …" or "File too large (1 GB maximum)" below them. Qualifying files show only their name and size.

## Related articles

- [Upload an audio or video file and get a transcript](https://docs.ardge.com/en/knowledge/scribestt/upload-and-transcribe)
- [What to do when a transcription fails](https://docs.ardge.com/en/knowledge/scribestt/transcription-failures)


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