I have a series of Power BI reports running through the on-premises Report Server that are being viewed in my application through embedding in an IFrame. The report page size is custom (1600 x 850), and the IFrame is also defined as 1600 x 850, but when I view the report, it appears as a substantially smaller box within the frame.
I'm pretty sure this is related to the rendering of the report, because the report tabs appear to run the entire width of the frame.
How do I get my report to show at full width?
We are not able to hide grey area completely, but we can try to mitigate this. Based on my test in Power BI report server October version, when we set report page size 1600*850, and set the Page View as Actual Size. With below embed code:
<iframe width="1600" height="850" src="http://<server name>/Reports/powerbi/Word%20Cloud%20Visual?rs:embed=true" frameborder="0" allowFullScreen="true"></iframe>
The report display in iFrame with less grey area. In your scenario, please try to run the same report server version as ours and use same settings to test again.