When I send a new link on Telegram, it automatically reads Open Graph data of the URL and generates a preview of the page.
When the Open Graph data of the same page changes, though, Telegram doesn't update its preview: it has cached the old Open Graph data!
How do you clear the Open Graph cache?
For the URL https://asp.net/
Telegram is reading the following tags:
<meta property="og:site_name" content="Microsoft">
<meta property="og:title" content="ASP.NET | Open-source web framework for .NET">
<meta name="twitter:image" content="https://dotnet.microsoft.com/images/redesign/social/large.png">
<meta property="og:description" content="ASP.NET is a free web framework for building great Web sites and Web applications using HTML, CSS and JavaScript." />
And is generating the following preview:
You can send the link [up to 10] you want to update to this Bot
and it will scan your site and generate the new image thumbnail
, site name
and description
.
Note: You may need to restart your Telegram client to see the updates
Images are cached too. Update them the same way. Be sure they're specified using Open Graph but note you do not need to use the prefix
attribute on your html
tag to define the OG namespace.
Use a pattern like the following pattern for your web address:
http://{webpage address}?v={number}
Then replace previous number
with a new one to force telegram update og
data.
For example use this:
http://www.example.com/mypage?v=3
Instead of:
http://www.example.com/mypage