Log File Analysis For SEO: How To Do It

In my opinion, log file analysis is one of the most underrated pieces of SEO analysis you can conduct – a fairly bold statement for sure – but if you have the ability to see how Google is actually crawling and understanding your website, as opposed to “emulating it” through tools like Screaming Frog, then this data is one of the most valuable insights that you can have to really understanding how Google views your website and more importantly how it sees the different sections connecting together.


Now I’m not saying there isn’t value in emulation tools, there’s a lot, and over the years I’ve used them significantly to help uncover potential technical issues across websites with great success – but in recent years I’ve really come to understand the value of Google’s direct crawl data and how when used properly, it can really help you to uncover potential blockers, issues and challenges on the website, in addition to understanding how to overcome these – that’s why I think that log file file analysis is an essential element of any complete technical audit.

What Is Log File Analysis?

Log file analysis for SEO is a process of examining the server log files to gain insights into how search engine crawlers and bots interact with a website. When a search engine crawls a website, it records the activity in the server log files, which can provide valuable information about how the site is being crawled, what pages are being visited, and how often. By analyzing these log files, SEO professionals can uncover issues that may be hindering the site’s performance in search engine results pages (SERPs) and identify opportunities to improve it.

Log file analysis involves a range of tasks, including identifying the search engine bots that are crawling the site, analyzing the frequency and duration of their visits, and monitoring the crawl budget allocated to the site. Additionally, log file analysis can help identify crawl errors, such as broken links or pages that return a 404 error, and ensure that search engine bots are able to access and crawl all of the site’s important pages. By using log file analysis to optimize a website for search engines, SEO professionals can help ensure that the site is easily discoverable by search engines and ultimately improve its visibility and rankings in SERPs.

Why Do I Need Log File Analysis?

Log file analysis is valuable for SEO for several reasons:

💡 Discovering crawl issues: Log files can help SEO professionals identify crawl issues that may be preventing search engine bots from discovering and indexing important pages on the site. This includes identifying broken links, pages returning a 404 error, or pages that are too slow to load, among other issues.

💡 Understanding crawl behavior: By analyzing log files, SEO professionals can gain insights into how search engine bots are crawling the site, such as which pages are being crawled most frequently, how often the site is being crawled, and which bots are crawling the site. This information can help inform SEO strategies and optimize the site for better search engine visibility.

💡 Improving crawl efficiency: Log file analysis can help optimize crawl budget by identifying pages that are being crawled unnecessarily or too frequently. This allows SEO professionals to prioritize the crawling of important pages, ensuring that they are crawled and indexed by search engines.

It provides valuable insights that you can’t get elsewhere and as a result, can help you uncover errors which might have previously been missed.

What Do I Need For A Log File Analysis?

To perform log file analysis, you will need access to the server log files that record the activity on your website. There are different types of log files that can be used for log file analysis, depending on the server and the software used to generate the logs. The most common types of log files are:

💡Apache log files: Apache is a popular web server software, and Apache log files are commonly used for log file analysis. Apache log files are typically stored in a plain text format and contain information such as the IP address of the user, the timestamp of the request, the requested URL, and the status code of the response.

💡NGINX log files: NGINX is another popular web server software, and NGINX log files are similar to Apache log files. NGINX log files typically contain information such as the IP address of the user, the timestamp of the request, the requested URL, and the status code of the response.

💡IIS log files: IIS is a web server software developed by Microsoft, and IIS log files are commonly used on Windows-based servers. IIS log files typically contain information such as the IP address of the user, the timestamp of the request, the requested URL, and the status code of the response.

Regardless of the type of log file, it is important to ensure that the log files contain the necessary information for log file analysis. This typically includes the user agent string, which identifies the search engine bots that are crawling the site, and the referrer, which identifies the source of the request (such as a search engine results page or a backlink).

What Should I Use For Log File Analysis?

There are several log file analysis tools available that can help you efficiently and effectively analyze your server log files. The choice of which tool to use will depend on your specific needs and preferences. Here are a few popular options:

💡Google Search Console: Google Search Console provides a range of SEO tools, including log file analysis. The log file analysis feature allows you to upload your server log files and view reports on how Google crawls your site. You can see which pages are being crawled most frequently, identify crawl errors, and optimize your crawl budget.

💡Screaming Frog Log File Analyzer: Screaming Frog Log File Analyzer is a desktop application that allows you to analyze log files from multiple sources, including Apache, NGINX, and IIS. The tool provides detailed reports on crawl behavior, including the frequency and duration of bot visits, and allows you to identify crawl issues and optimize crawl budget.

💡Logz.io: Logz.io is a cloud-based log management platform that offers log file analysis as part of its suite of features. The tool allows you to collect and analyze log data from multiple sources, including web servers and applications, and provides advanced analysis and visualization features, such as machine learning-powered anomaly detection and customizable dashboards.

💡ELK Stack: ELK Stack is an open-source log management platform that includes Elasticsearch, Logstash, and Kibana. The platform allows you to collect, analyze, and visualize log data from multiple sources, including web servers, applications, and network devices. The ELK Stack offers advanced analysis and visualization features, such as machine learning-powered anomaly detection and real-time data monitoring.

These are just a few examples of the many log file analysis tools available. When choosing a log file analysis tool, consider factors such as your budget, the size of your log files, the complexity of the analysis you need to perform, and the level of technical expertise required to use the tool.

Can I Use Excel To Analyse Log Files?

Yes, Excel can be used to perform log file analysis, although it may not be the most efficient or scalable solution for large log files. Excel can be used to open and sort log files, filter data based on specific criteria, and perform basic calculations and analysis.

To get started with log file analysis in Excel, you can open the log file in Excel and use the “Text to Columns” feature to separate the data into different columns based on delimiters such as spaces or tabs. You can then use Excel’s filtering and sorting features to isolate specific data, such as search engine bot activity or crawl errors.

However, keep in mind that Excel has some limitations when it comes to handling large log files, such as performance issues and the potential for data loss or errors. For larger log files, it may be more efficient to use specialized log file analysis tools that are designed for handling large amounts of data and providing more advanced analysis and visualization features.

What Are The Main Things I Should Look For In Log File Analysis?

When analyzing server log files, there are several key metrics and insights that you should look for to optimize your website’s SEO performance. Here are some of the main things to look for in a log file analysis:

⚡️ Crawl frequency: Look at how often search engine bots are crawling your site, and which pages are being crawled most frequently. This can help you identify pages that are being crawled too frequently or not frequently enough, and optimize your crawl budget accordingly.

⚡️ Crawl errors: Identify any crawl errors or issues that search engine bots are encountering when crawling your site. This can include broken links, server errors, or blocked pages.

⚡️ Internal linking: Analyze the internal linking structure of your site by looking at which pages are linking to each other and how often. This can help you identify pages that may need more internal links to improve their SEO performance.

⚡️ Response codes: Look at the response codes in your log files to identify any pages that are returning errors or redirects. This can help you identify pages that may need to be fixed or redirected to improve your site’s user experience and SEO performance.

⚡️ User agents: Identify the user agents in your log files to see which search engines and bots are crawling your site. This can help you optimize your site for specific search engines and understand how different bots interact with your site.

⚡️ Referrers: Look at the referrers in your log files to see where your traffic is coming from, such as search engines, social media, or other websites. This can help you identify which sources are driving the most traffic to your site and optimize your marketing efforts accordingly.

These are just a few examples of the main things to look for in a log file analysis. Depending on your specific needs and goals, you may also want to analyze other metrics, such as page load times, click-through rates, or conversion rates.

How Much Time Does It Usually Take?

The time it takes to analyze log files for SEO purposes can also vary depending on various factors such as the size of the log files, the complexity of the website or application, the level of detail required, and the tools and methods used.

For smaller websites, log file analysis for SEO purposes may only take a few hours or a day. However, for larger and more complex websites or applications, the analysis may take several days or even weeks.

In addition, the level of detail required in the analysis will also affect the time it takes to complete. A high-level analysis that provides a general overview of website traffic and user behavior may take less time than a detailed analysis that requires deeper insights into specific user actions and behavior.

It’s also worth noting that log file analysis for SEO is an ongoing process that requires regular monitoring and analysis. As such, the time it takes to complete the analysis may depend on the frequency and extent of analysis required for your specific needs.

How Many Files Do I Need?

The number of log files you need for log file analysis for SEO will depend on the size of your website or application, the volume of traffic and user interactions, and the level of detail you require in your analysis.

Ideally, you should analyze all the log files generated by your web server to get a comprehensive view of user behavior and traffic on your site. However, this may not be practical or necessary for all websites.

In general, it’s recommended to analyze at least a few weeks’ worth of log files to get a good understanding of user behavior and traffic patterns. This will help identify any issues or opportunities for improvement in your website’s SEO performance.

You can also consider filtering the log files to focus on specific sections of your website or specific types of user behavior, which can help reduce the volume of data you need to analyze and make the analysis process more manageable.

Ultimately, the number of log files you need for log file analysis for SEO will depend on your specific needs and goals. It’s important to work with a knowledgeable SEO professional or use reliable SEO tools to help you determine the best approach for your website or application.

How Do I Get Started?

If after reading the above you want to get started on log file analysis then get in touch with your web developers (or your clients!) to get the files you need and get started. This valuable insight can really help you to identify any potential issues within the crawl and most importantly help to ensure that Google is crawling the website in an efficient manner – and getting to the pages that you need it to!


To find out more about log file analysis or for help with your SEO get in touch!