The official Facebook limitation for sending attachments in Messenger is 25 MB.
However, due to the encoding that ensures file compatibility, the size of the file might change when sent in Messenger.
The official limit in ManyChat is 23,8 MB, though we strongly recommend using files of a smaller size (preferably 10 MB or less) because the files can become much bigger after encoding on Facebook's side.
Please keep in mind that the same limitations apply to all files sent in Messenger, including the ones uploaded through the User Input feature.
If a file in your Flow is not sent as expected, it might be too big for Messenger.
Here are some things you could do to fix it:
- Downsample your video to standard web sizes (no HD)
- Compress video and change file type from .mp4 to .mov
- Change dimensions of the video down to a smaller size (the perfect dimensions would be 270x480)
- Use MP3s instead of AAC or WAV
- Use optimized JPEGs instead of RAW or PNG24
- Keep your animated GIF files to less than 10 seconds in duration.
Hope this helps!