How do you clear the Open Graph cache of an URL on Telegram?

问题

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?

Preview Example:

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:

回答1:

Use @webpagebot

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.

---

Second solution:

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

回答2:

Go to @webpagebot and send the link (up to 10) you want to update.

回答3:

I've solved this problem by using bitly.com and changing url.

回答4:

you must chat with @webpage both and tell him in chat

https://theurlyouwanttoupdate.com /updatepreview

来源：https://stackoverflow.com/questions/34707915/how-do-you-clear-the-open-graph-cache-of-an-url-on-telegram