You pick a video in WhatsApp and get "The file format is not supported", or the video sends but won't play on the other end, or it arrives without sound. The video itself is usually fine. What's going on is that WhatsApp handles videos in two very different ways, and only one of them is fussy.
#Two ways to send a video
Sending as media vs sending as a document
- Plays right in the chat
- WhatsApp compresses it
- Up to 16 MB
- Fussy about formats - MP4 is safest
- Arrives as a file to open
- No compression - original quality
- Up to 2 GB
- Any file type at all
When you send a video the normal way - from the gallery or camera - WhatsApp processes it: it compresses it so it loads quickly, gives it a preview, and plays it inside the chat. That processing is built around MP4 video, and it's what refuses files it doesn't understand. When you send the same video as a document, WhatsApp just passes the file along untouched, like an email attachment.
#Why WhatsApp refuses a video
- The file type. MP4 is what WhatsApp's video processing expects. MKV, AVI, WebM, WMV and FLV files are often refused or fail to process.
- The format inside. A file can end in .mp4 and still contain video or audio WhatsApp can't handle - old DivX-era video, AV1, or Dolby (AC-3) audio that many phones can't play. Checking with VLC (Tools → Codec Information) shows what's inside.
- The size. Videos sent as media are limited to 16 MB. Over that, WhatsApp asks you to trim the video or won't send it.
- A damaged or incomplete file. A video that was still downloading or copying when you tried to send it can be unreadable.
#Fix 1: convert it to MP4
An MP4 with H.264 video and AAC audio is the format WhatsApp handles most reliably on every phone. Wave converts MKV, AVI, WebM, WMV, MOV and most other video types to that in your browser, without uploading the file - start with MKV to MP4 or the full list. When only the audio is the problem, Wave copies the video untouched and converts just the sound to AAC, so it's quick. Then move the MP4 to your phone and send it normally.
#Fix 2: send it as a document
If you want the video to arrive at full quality, or it's in a format you'd rather not convert, send it as a document: in the chat, tap the attach button, choose Document, and pick the video file. It goes through untouched, up to 2 GB. The trade-off is that it doesn't play inside the chat - the other person downloads it and opens it with their own video player, so for unusual formats they may need an app like VLC.
#Fix 3: make it smaller
If the problem is the 16 MB limit, you can trim the video in WhatsApp's editor before sending, compress it yourself, or send it as a document instead. Compressing it to a target size, rather than letting WhatsApp do it, usually looks better. Compress video for WhatsApp has the maths for hitting 16 MB at different lengths.
#Better quality when sending as media
When you send a video normally, WhatsApp shows a quality option in the editor before you send: choose HD rather than standard. It's still compressed, but much less. For anything where quality really matters - a video for printing stills from, editing, or keeping - send it as a document instead.
#When you've received a video that won't play
If a video someone sent you shows only a black picture, or plays without sound, the cause is usually a format your phone can't decode rather than WhatsApp itself. Video plays sound but no picture and MP4 has no sound explain the fixes. The simplest one is often asking the sender to share it as an ordinary MP4, or opening it in VLC.
#The short version
- Sending as media is fussy (MP4, up to 16 MB); sending as a document takes any file up to 2 GB, uncompressed.
- "Format not supported" usually means MKV, AVI, WebM or an unusual codec. Convert to MP4 with H.264 and AAC.
- Too big: trim, compress to a target size, or send as a document.
- For better quality as media, choose HD before sending.