What is the best program to review report rdl file?

A RDL file is a report definition language (RDL) file. It has every bit of information in the file.

You have several options to look at a report's rdl file as shown (by right clicking the (any report) reportany.rdl file.

XmlRdl_0

You could open in Notepad and it is going to be a very large file and you may get yourself lost in it without recognizing the key areas. Even using Microsoft Edge it is the same. You could open in Microsoft Visual Studio, but not every one may have it.
The reccommendation is XML Notepad. This is a good application to review the properties of a report rdl file.
You may download XML Notepad as described here. it is free.
Launch XML Notepad and click FIle menu to open the rdl file. In this case I am using a simple file called SimpleReport.rdl.
The file gets opened as shown. Now you see why I recommend this application. You canveyr clearly see how ggthe report is constructed.


XmlRdl_1.png

Expand the DataSource to see the details.



XmlRdl_2.png

Now open the DataSets node as shown.

XmlRdl_3.png

Click the Fields to see the fields in the data as shown.

XmlRdl_4.rdl

Well, you can also see the report design.

XmlRdl_5.rdl

Explore more and enjoy!

I guess you agree with my assertion that XML Notepad is the best to see the report rdl file.