Github html preview from html file not working

Question

I Have seen several posts regarding this feature to preview HTML file on GitHub. Some suggest prepending https://htmlpreview.github.io/ before the real URL and some suggestions to create GitHub pages that I don't want to do now because then I have to re-create most of the thing on .yml

But my confusion is why this link showing HTML preview but not mine when I prepend the same string on my repo's HTML page. Please let me know If any other way I can see the HTML preview on github

Working:

https://htmlpreview.github.io/?https://github.com/bartaz/impress.js/blob/master/index.html

Not Working:

https://htmlpreview.github.io/?https://github.com/sany2k8/setuptools/blob/master/How_to_Install_Spark_on_Ubuntu.html

Showing 404 Not Found

Error: Cannot load https://raw.githubusercontent.com/sany2k8/setuptools/master/How_to_Create_Github_Pages.html: 404 Not Found

Answer 1

Check these steps:

-Your repository is public.
(Settings>General>Danger Zone>Change repository visibility>Make public)
-The size of the files are not very large.
-The Repository link is in HTTPS and not in SSH.

EDIT: I found this question about the private repository and preview, if you want to take a look.

Answer 2

When your html file is excessively big then often github may fail to open the file. In such cases you can check the raw version of the HTML file.