MARKDOWN format - how to indicate Image Size ?




  • Official comment

    Hi Patrice,


    The only tags supported are ( as described:

    Interaction with Rainbow clients

    At this time of writting, Rainbow clients manage Message language and are able to display messages using a Markdown content type. This feature is not officially supported but if your Node.JS application interacts with a Rainbow official client, this can help.

    Here is the list of Markdown tags supported by the Rainbow official Web application (Rainbow Web client and Rainbow Desktop client):
    • Headers: #H1 to ######H6
    • Emphasis: *italics* and **bold**
    • Lists: -, + or `* ``
    • Links: [a link](
    • Images ![alt text](
    • Code: Inline code has back-ticks around it.
    • Blockquotes: > a Blockquote.
    Note: Other Markdown tags can be used specifically if you have provided your own end-user application but will not be rendered correcly in the Rainbow official clients.

    Subject is used when displaying Rainbow notification messages.

    Note: At this time of writing, Markdown is not supported by the Rainbow mobile clients.

    and no way to force an image size.

    No way described also in official Markdown doc:

    Up to you to resize the image before including them to the message.  Or if your server is "resize on the fly" - capable, use it 
    For example on some servers: src="/images/the_img.jpg?w=120" to force it at 120px width

    Warning also to share an https// image url !  Instead of that all clients in HTML5 will display a Warning "mixed content".


    Best regards,


    Comment actions Permalink
  • Patrice COHAUT

    On-the-fly resizing must be supported by Rainbow Clients (web, desktop, smartphone) . So if you don't support, as indicated, this means that I must must have a "resizing process" on server side which is very time-consuming and unefficient. Bad news


    Comment actions Permalink

    Please add a request to Markdown project for adding an image size to

    • Images ![alt text](

    =>  not linked to Rainbow.


    Please read my reply.  You said "On-the-fly resizing must be supported by Rainbow Clients", I said: up to your server, where the image is hosted (not Rainbow servers) to resize the image if possible.

    Or as I said also, before attaching the IMG in your Markdown message, up to you to resize it in your code !

    Comment actions Permalink
  • Patrice COHAUT

    understand but when the IMG is a LINK (URL to another site than us). [like in NEWS FEEDS] where we link to the outher server image, the lack of resizing support on Rainbow imposes some IMG download + resize + storage for nothing while a simple MARKDOWN support would be enough. 

    Comment actions Permalink

    Client's side, if you share an image in a conversation, it's also an URL link, as if it is stored Rainbow's side. 
    And the resize is also done "on the fly" client's side or server's side for larger images.

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