Web Messaging SDK file upload size limit validation

Trying to enforce file size limits on the client side before sending via the Web Messaging SDK. The docs are vague on the exact max bytes for images, so I added a check in the upload handler.

if (file.size > 5 * 1024 * 1024) {
 // reject
}

Is 5MB the hard limit? We’re seeing uploads fail silently after this check passes.