To enable display of HTML and PDF and other sanitized datatypes resulting from a tool, add these to the Galaxy display whitelist.
The operation is within the Galaxy UI under Admin > Tool Management > Manage whitelist.
You can also do this line-command here: https://docs.galaxyproject.org/en/latest/admin/options.html#sanitize-whitelist-file
Thanks! Jen, Galaxy team
If you run fastqc in terminal at e.g.
fastqc --outdir ~ file.fastq.gz it will create, in your home directory (~), an html file that you can open with your favourite web browser to view graphs, as well as a .zip archive that you can extract and view .PNG image files using your favourite image viewer program (such as the default Photo Viewer program on Windows PCs).
On Galaxy, a modern web browser like Chrome will be able to display the graphics (PNG files) in the "...: Webpage" file generated.