How Viber select the image to display from HTML page
when I send some URL to someone via Viber the Viber load the URL and displays image representing the HTML page.
How to tell the HTML page what image it should be?
Answer
You should use Open Graph protocol. You can simply add this snippet to your page <head>:
<meta property="og:type" content="website">
<meta property="og:site_name" content="Название сайта">
<meta property="og:title" content="Заголовок">
<meta property="og:description" content="Описание.">
<meta property="og:url" content="http://example.com/page.html">
<meta property="og:locale" content="ru_RU">
<meta property="og:image" content="http://example.com/img.jpg">
<meta property="og:image:width" content="968">
<meta property="og:image:height" content="504">
<meta name="twitter:card" content="summary_large_image">
<meta name="twitter:title" content="Заголовок">
<meta name="twitter:description" content="Описание.">
<meta name="twitter:image:src" content="http://example.com/img.jpg">
<meta name="twitter:url" content="http://example.com/page.html">
<meta name="twitter:domain" content="example.com">
<meta name="twitter:site" content="@">
<meta name="twitter:creator" content="@...">
Image size should be 968x504px. Read more here
Cheers!