WhatsApp and the other channels refuse a file that is too big, and every send of that file fails. Mampu AI checks the size the moment you add a file, so a file that is too big never reaches your customers’ messages. You see a message such as This image is 5.52 MB. The limit is 5 MB, so please upload a smaller file. and the file is not saved.
The limits
Files your AI agent or a Flow Agent can send on any channel must fit every channel you might use:
| File | Largest size |
|---|---|
| Image (JPEG, PNG and other pictures) | 5 MB |
| Video | 16 MB |
| Audio | 16 MB |
| Document (PDF and other files) | 25 MB |
These limits apply to:
- media in AI Knowledge answers, FAQs, promos and product photos
- attachments on a Flow Agent’s Send message step
- media in Settings → Message Sequences steps
The picture, video or document at the top of a WhatsApp template is only ever sent on WhatsApp, so it follows WhatsApp’s own limits: 5 MB for an image, 16 MB for a video and 100 MB for a document. This applies in Settings → WhatsApp Templates, when you create a template on an inbox, and when you pick a file for a template in a reply or a blast.
A template whose file is already too big
A template may still hold a file that was uploaded before sizes were checked. When you pick that template in a conversation reply, a new conversation or a WhatsApp blast, its file shows in red with the reason, and Send message or Create stays off until you replace it:
- Click the × on the file.
- Upload a smaller file, or paste a link to one.
- Send or create the blast as usual.
To fix the template for every future send, edit it in Settings → WhatsApp Templates and upload a smaller example under Header. WhatsApp reviews the change like any other edit. A message sequence step that uses the template shows the same reason under its media link, and the sequence cannot be saved until the file fits.
Making a file smaller
- Pictures: save as JPEG instead of PNG, or reduce the width to around 1600 pixels. A photo that size is usually well under 1 MB and still looks sharp on a phone.
- Videos: export at 720p, or trim the clip.
- Documents: use your PDF app’s Reduce file size or Optimise option, or split a long document.
A file you upload in the Playground to play the customer’s side of a test chat is not limited in the same way, because it stands in for what a customer sends you.