We usually do an SEO audit to find out the common technical SEO issues that preventing our site from ranking. Here are the 10 on-site technical SEO factors you need to consider in an SEO audit.

1) Sitemaps
2) Robots.txt
3) Crawl Errors
4) Multiple URLs
5) Does the Site Have an SSL Certificate
6) Minifying CSS & JavaScript Files
7) Image Optimization
8) HTML Errors / W3C Validation
9) Mobile Optimization & Testing
10) Forcing a Single Domain

If I miss any technical SEO factors in the above list, let me know them in the comments.