Mobile-friendliness: Test the mobile-friendliness of your website using the Mobile-Friendly Test Tool of Google Search Console. Some quick tips Increase font size, Compress images, Use AMP
Multiple versions of the site: Make sure Google indexes only one version of your site and all other versions redirect to that version only.
Website loading speed: Check website load time using Google PageSpeed Insight.XML sitemap: Create and submit XML sitemap. The sitemap should only contain status code 200 URLs – no redirects, 404s, or non-canonical URLs should be in it.
SSLNot found (404)Soft 404Canonical Tag Issues:Internal Linking Issues: Orphaned pages, Pages with high click depth, Errors
Indexed Versus Submitted PagesRobots.txt: Check disallowed and allowed paths are in accordance with your plan
Coverage/Indexing Issues: Make sure your Google Search Console shows zero coverage “error” and “valid with warning” issues. Additionally, try to optimize the score in the Google Lighthouse test.
Google Site Command: Gives an approximation. An extremely low number represents an indexing blockage issue and an extremely high number hints canonicalization is allowing duplicate URLs.
Mixed Content: All of the website URLs should use HTTPS. if any URL uses HTTP, use 301 permanent redirects to fix that issue.
Broken links: Use Dr.LinkCheck to find broken links
Average Organic search trafficManual actionWebsite architecture: Internal links, Each page shows breadcrumbs, consistent URL structures, Pages and content are grouped topically, Useful Navigation menus that improve UX, Users can reach to any page with a few clicks (usually three), Topic Clusters
Schema Markup: Schema isn’t a mandatory thing but if you use it, make sure it is set up properly. Use the Rich Result Testing Tool and Google Search Console. Visit the “Enhancements” section of Search Console including the “Unparsable structured data” report. Not having this section in the search console means there is no related issue. You can also use Google’s structured data testing tool.
Security Issues: Check the “Security Issue” in the Google search console i.e. Security & Manual Action > Security Issue
On-Page SEO Audit
Keyword cannibalization: Check for Keyword cannibalization in Google Search Console.
LSI Keyword:Content AuditZombie Pages: Identify (Normally done by the site owner), redirect (301) or, delete (410) of unwanted pages on your website.
Metadata: Check for duplicate metadata, availability, and length of metadata used.
Internal duplicate content: Use Siteliner to check internal duplicate content.
On-page fundamentalsKeyword rankingsFeatured Snippet opportunities: Mobile-optimized content, HTTPS, H2-H3, Short answers (42 words), Outbound links
Modern copywriting practices: Very short introductions, Small paragraphs, Lots of subheaders, Visuals, images, and video
Social Media IntegrationBlogContact InformationImage OptimizationURL Structure
Off-Page SEO Audit
Competitive analysis: what keywords the site’s main competitors are ranking for? patterns in the pages that are ranking, who’s linking to those pages.
Link Quality: spammy, low quality, irrelevant and unethical backlinks should be singled out through a backlink audit
Link Profile: Links should come from a variety of sources. Getting too many links from too few types of websites is unnatural.
Disavow List: Suspicious Backlinks should be disavowed
Tools for SEO Audit
Integrity (for Mac users) and Xenu Sleuth (for PC users).
Google Tag Manager.
Google Tag Manager Chrome Extension.
Annie Cushing’s Campaign Tagging Guide.
Google Analytics (if given access).
Google Search Console (if given access).
Bing Webmaster Tools (if given access).
You Get Signal.