Supported Audio & Video Formats
Audio and video processing is available on Professional plans and above. Community-tier accounts can upload documents and images only.
Audio formats
| Format | Container | Notes |
|---|---|---|
| MP3 | MP3 | Most common; widely compatible |
| WAV | WAV | Uncompressed; preferred for preservation masters |
| M4A | MP4 | Apple's lossless / lossy container |
| FLAC | FLAC | Lossless compression; recommended over MP3 for archival |
| OGG | OGG | Open container; less common in archives |
| AAC | AAC / M4A | Lossy; common from mobile recorders |
File size limits (Professional / Team): 500 MB per file. Enterprise: unlimited.
Video formats
| Format | Container | Notes |
|---|---|---|
| MP4 | MP4 (H.264 / H.265) | Most common; recommended for upload |
| MOV | QuickTime | Common from broadcast and consumer cameras |
| WebM | WebM | Open web video format |
| AVI | AVI | Older container; supported for historical files |
| MKV | Matroska | Modern open container |
File size limits (Professional / Team): 2 GB per file. Enterprise: unlimited.
A video item counts as 3 items against your monthly quota — transcription, frame extraction, and content analysis run in parallel.
Preservation guidance
The Library of Congress maintains recommended formats for archival use. In summary:
| Use case | Preferred | Acceptable | At-risk |
|---|---|---|---|
| Audio master | WAV (uncompressed, 24-bit / 96 kHz) | FLAC | MP3 |
| Audio access copy | FLAC | MP3 320 kbps | M4A AAC |
| Video master | MP4 H.264 (high bitrate) or MOV ProRes | MKV | AVI, WMV |
| Video access copy | MP4 H.264 | WebM | older codecs |
The Archiver doesn't transcode your uploads — what you upload is what's stored and exported in BagIt / preservation packages. Upload the highest-quality version your plan allows.
Container vs codec
A format is the container; what's inside is the codec. The Archiver supports any audio or video codec that ffmpeg can decode (which is to say, effectively all of them). You shouldn't ever hit a "codec not supported" error unless the file is corrupt.
What about subtitles?
If you have an existing transcript or subtitle file (SRT, VTT), upload it alongside the media and the platform will use it instead of running its own transcription. The item still counts as the relevant item cost (1 for audio, 3 for video) because vision and content analysis still run — but transcription is skipped.
See also
- Playing audio & video — the inline player
- Transcription — automatic speech-to-text
- Uploading files — overall plan limits