The information on the internet right now at the moment is that you need to be using Canary to use reader mode in Chrome, not exactly like that, you can enable reader mode in the stable version of Chrome 73 and even in old versions also, here is how.
How to enable Reader mode in Chrome stable version
1. Right click on Chrome shortcut on the desktop and select Properties
2. In the Target field after Chrome.exe” give a space and add below switch
3. Click Apply, when asked for Admin rights, permit by clicking “continue”.
4. Launch Chrome, you’ll notice Distill page option in the menu.
Do note DOM Distiller doesn’t work on Chrome internal pages such as new tab, visit webpage having some good information or long text, click “Distill Page” menu item.
To come out of reader mode, click the back button, the original article will be restored and displayed by the Chrome browser. You can manually visit chrome://dom-distiller and trigger reader mode by adding an article.
We’ve mentioned upcoming features for reader mode here since most don’t know our post, we’re letting you know here also.
A menu to adjust the font size and the type and a toggle button for Reader mode are coming to Chrome Canary in future updates. Yes, you may need to be using Canary to spot them.