This is the second post in the “How to Perform an Onsite Audit for SEO” series. In the coming months, we’ll cover the other essentials: test and improve/repeat.
Our first post gave recommendations for the type of data you should use to inform your technical 
onsite SEO audit. We discussed some of the ways to conduct SEO data research, such as using crawlers that crawl your site, reviewing search provider webmaster tools (WMT) data, pulling backlink data, and gathering keyword data. Once this is done, you’ve got plenty of data. But what’s next?
In this post we’ll discuss the questions you should ask yourself as you review data. Additionally, we’ll provide some pointers on how best to analyze SEO. There are some amazing resources on the web which provide specific deep dives into each of the topics we’ll discuss, so you’ll be able to conduct further research based on the needs of your site. Let’s get started!
Keep Your Data, and Take Baselines
Data pulling, the first step in any SEO audit, is useful for many reasons. The data can serve as your benchmark to compare to when you complete the next audit, or to measure performance at any time. Ideally, technical SEO audits should be performed on a regular basis at least annually). As you make improvements, based on the findings from your audit, you’ll want this baseline data to measure 
against. Bottom line: keep your data in a safe place and at the ready, to reference in the future.
Measuring SEO improvements can be a tricky exercise. That’s why it’s important to pull from as many data sources as possible, so you can correlate improvements or declines to your activities. When you’re ready to measure, you don’t want to be put in the position of searching for your historical data – only to realize it’s no longer available. Keep your data in a safe, stable, known place. It’s as simple as that.
SEO Data Analysis Best Practices
Some of the best information for an audit is given to you directly from the search providers themselves. The webmaster tools that both Google and Bing provide gather amazing information about the search health of your site. Learn about accessibility stats, indexing health, and more. By asking yourself the following questions and gathering the answers, you’ll start to form your analysis.
- Are there any message notifications, indicating prior penalties?
- How does the site appear for branded queries, and in general how is search appearance?
- Do the webmaster tools detect structured data or HTML improvements, and if so any recommendations to improve?
- Using search analytics, examine keywords driving the most impressions, the most clicks and the highest CTR, best average position. Are there any keywords which are (much higher or much lower) in clicks, impressions, CTR or position?
- Are there suspicious backlinks observed using webmaster tools?
- Are there sitewide (from someone else’s site) links present?
- Are there over-optimized internal links observed?
- Is international targeting or geo-location set up properly?
- Does the site pass webmaster tools mobile tests without error?
- Has the site submitted a sitemap? If so, are there errors with the sitemap?
- Are there discrepancies between the number of pages in the sitemap and the # of indexed pages recorded?
- Is a robots.txt file uploaded, and does it test without error? Are there blocked resources?
- Were there any crawl errors observed?
- Compare the number of pages indexed in Bing to the number indexed in Google. Is the number disproportionate?
Through web analytics tools like Google Analytics, you’re able to understand your site visitors a bit more. These questions can be adapted to other website analytics programs as necessary, but provide a great start to understanding and analyzing your visitors today.
- Do all pages have analytics tracking codes?
- Is traffic consistent or are large increases and drops evident?
- If drops are evident, what are the suspected causes, and do they correlate to any algorithm updates, or are they simply seasonal?
- What does organic traffic information tell you about search visitors in comparison to other traffic sources? If performing worse, why?
- Review engagement data such as return visitor percentages, pages per visit and time on site for pages and traffic sources, do any perform outside of your sitewide averages?
- Examine annotations, do they provide insight into activity important to SEO?
- How much mobile traffic do you receive, and how does it perform?
- If your site is linked to Adwords, how does traffic perform from search ads?
- If your site is linked to webmaster tools, which keywords are driving the most valuable traffic?
- Do your site visitors use site search? If yes, what aren’t they finding on their own which requires them to use site search in the first place?
- If using ecommerce tracking, what are the most profitable lead sources and how does search perform in comparison to the most profitable source?
Backlink Analysis
Algorithm updates aimed at improving the reliability of search results happens just about every 
day (an estimated 500–600 time per year). Significant updates such as Penguin have required SEOs to pay much more attention to the health of their backlinks. That’s why we recommend, for a thorough onsite technical SEO audit, to include a review of your backlinks. How does the health of your backlinks stack up? Start your analysis by asking yourself questions like these:
- Is there a disproportionate number of total links to linking root domains?
- What is the percent of over-optimized anchor text?
- Are a variety of anchors used or limited in use?
- Are there fresh, incoming links?
- Is there an even distribution of links to pages on the site?
- What is the average authority and toxicity of backlinks to the domain?
- Are links relevant and appropriate to represent the quality of your site?
Keyword Analysis
Keywords are what searchers use to find your content. A good understanding of your keyword diversity, success, and opportunity are a part of any SEO technical audit. Dive into your keyword analysis by asking questions like these:
- Which keywords drove the most revenue for my business?
- Which keywords have the highest search volume but lowest keyword difficulty?
- Which keywords are close to making the first page?
- Which keywords are ranking the best?
- Are the web pages ranking optimized for the best keywords?
- Is there a canonical strategy evident?
Additional Analysis
If you’ve made it to this point you’ve more than scratched the surface of your site. You’re likely already anxious to get started fixing and updating the items you’ve uncovered. There’s actually a bit more you can review and analyze.
This additional analysis requires you to have an understanding of SEO best practice elements that we don’t cover in this post. We hope the resources provided for you below will help you learn more and allow you to move forward with a deeper dive.
- A soup-to-nuts SEO audit primer: “14 Steps to Complete an Onsite SEO Audit”
- Are best practices followed for meta data such as meta title length, meta descriptions, meta keywords? “Metadata & You: Best Practices, Benefits & Implementation Made Easy”
- Do images contain image alt text with descriptive information? “Image Optimization and Alt Text Best Practices”
- Is a custom 404 page built, and if so does it follow best practices? “404 Best Practices”
- Review redirects, are 301s and 302s set up appropriately? “Redirection: SEO Best Practices”
- Is navigation and, if applicable breadcrumb, setup user friendly? “Guide to Site Navigation and SEO”
- Is content rich, with length and in diversity as well? “How Content Length Affects Ranking and Conversions”
- Is content duplicated or replicated elsewhere on the site or off the site? “Duplicate Content: SEO Best Practices”
- On which pages is the noindex tag placed on, and are the appropriate pages (such as “thank you” pages) noindexed? “What Should NOINDEX Do?“
- If an ecommerce site, are shopping feeds configured properly and do product pages follow best practices to avoid duplicate content? “The Ultimate Guide to SEO for E-Commerce Websites”
- If you have an international targeted site, is href lang set up to best practice standards? “Href Lang Tag: Best Practices”
- Do videos follow best practices with a sitemap, transcript, embeds, tagging and annotations? “Video SEO Guide: Optimization Best Practices”
- Are branded search results showing? Are local citations claimed, unduplicated and following best practice? “Local Search 101”
Have some additional analysis questions on performing an onsite audit for SEO that we didn’t cover? We’d love to hear from you in the comments below!