On-page is an important ranking factor for any website, whether it’s new or old. Hope this checklist will help your developers.
-Web URL should be secure HTTPS.
-Single version will be deployed www or without www and remaining all versions will 301 redirect to that version.
-Simple and easy keyword-based URLs.
-Don’t create directories further than three levels down from the root directory.
–Check all the web links working properly no 404 error appeared during navigation.
-Proper meta tags will be implemented (Title, Description Open Graph, Alt Tags.
-Google Data structure or schema will be implemented where it is required.
-Images should be compressed, So it will minimize load time and also alt tags will be added.
-Make sure to only use the H1 tag one time on the page.
-H2 tag will be used in sub headings of the page. (Not more than 3 times)
-H3 tag where it will be needed.
-HTML and XML versions of the sitemap will be added on the website.
-Robots.txt file should be written and added.
-Google and Bing webmaster code will be implemented.
-Google Analytics / Tag Manager code will be implemented.
-Use all Javascript codes at the bottom of the page code.
-Each Page should be tested with the following tools, and make sure all pages will be passed!
https://gtmetrix.com/ (Website Speed Check)
https://search.google.com/test/mobile-friendly (Mobile-Friendly Test)
https://search.google.com/test/rich-results (Google Data Structure Test)