Efficient crawling is one of the pillars of ecommerce Search Engine Optimization (SEO). 

But how do you ensure search engines are crawling your site efficiently? 

In this post, we'll talk about an advanced technical SEO tactic that's often ignored in ecommerce: log file analysis. 

It's a powerful tool that shows your ecommerce website's crawlability at a depth you've never seen before — unveiling hidden crawl issues as well as helping you improve indexation and boost overall search engine performance.

Keep in mind that, in the context of websites, ecommerce sites are often HUGE. 

We're talking about thousands, or potentially millions of pages and recorded activity. Not to mention complex site structures, especially for multi-brand retail with several product categories. 

Log file analysis will help you make sense of the chaos and identify hidden opportunities to boost your ecommerce SEO.

Here's how:

What is Log File Analysis?

In the context of SEO, log files are records of every server request that occurs on your website. 

Check out the example below:

Log file analysis aims to review, interpret, and convert this hodgepodge of records into actionable insights that will elevate your SEO. 

Sure, there are other methods of tracking page crawlability and diagnosing technical issues. But with log file analysis, you're getting raw, unfiltered data on how search engine crawlers interact with your website. 

This leads to optimization opportunities that most SEO analysis tools are likely to miss.

Why Log File Analysis is Crucial for Large Ecommerce Sites

Log file analysis is extremely helpful for large websites with complex structures, like online stores. 

You're looking at thousands if not millions of pages — a considerable chunk of which include dynamic content and are subject to frequent updates. 

This makes site crawlability and indexation all the more important. 

Remember, search engines like Google may have deep pockets, but they don't have infinite capacities to crawl pages and list them in search results. And without crawl budget optimization, your "money pages" could be losing out on valuable traffic, directly hurting the profitability of your ecommerce business. 

To identify crawlability issues, most website owners rely on tools like Google Search Console. It gives a broad overview of your ecommerce site's crawlability, including the underlying reasons and some of the pages affected. 

Looks useful, right? 

With log file analysis, you take a couple of steps further — diving layers deeper in terms of search engine bot behavior. Apart from crawlability problems, you can drill into data like crawl frequency, time of last response, status code inconsistencies, and other symptoms of crawl budget deficiencies.  

Key Insights Gained from Log File Analysis

Before you roll up your sleeves to conduct log file analysis for the first time, here's a rundown of the insights we'll focus on:

• Crawl Budget Optimization — Log file analysis is like a superweapon for crawl budget optimization. It equips you with in-depth knowledge on things like wasted crawls on low-priority pages (e.g., multi-step navigation pages and phased-out product pages) as well as neglected money pages (e.g., products, category pages, and other offer pages).
• Bot Behavior — Unlike Google Search Console, log file analysis tracks the crawling activity of different crawlers — from Bingbot to Yandex. Furthermore, it enables you to detect harmful bot activity, like content scrapers, spam bots, and ad fraud bots. 
• Error Detection — One of the first things you'll see in a log analysis report is a breakdown of status or response codes (e.g., 200, 404, and 301). Identifying pages with error codes (4xx and 5xx) lets you get to the bottom of these issues and fix crawlability.
• Seasonal and Traffic-Based Insights — Log file analysis reports include charts that visualize crawler activity over time, allowing you to gauge the impact of holidays and seasonal events on crawlability. Some analysis tools also track traffic-based data, like the number of server requests per country and user agent distribution.

With that out of the way, let's get to work. 

Steps to Conduct a Log File Analysis 

Below are the steps on how to conduct log file analysis:

1. Access Your Log Files 

Your website's log files are stored on your server, and accessing it can be as simple as navigating to the right folder from cPanel and downloading the right file. Just look for your logs folder (which can also be named "access.logs" or "access_logs") and download the largest and most recent file.

Another approach is to use a free, open-source File Transfer Protocol (FTP) client like FileZilla. It includes advanced features like bookmarking, remote file editing, and robust security. 

2. Import Your Log File

After downloading your log file, you're just about ready to analyze it. 

Technical SEO pros can have a more manual approach and throw it into a spreadsheet app. But this can get sticky, especially considering the size of log files for established ecommerce websites. 

For the sake of this guide, we're using SEO Log File Analyser by Screaming Frog, which comes with a free version. 

After downloading Log File Analyser, just drag and drop your log file into the main window. 

Prior to importing your log file, you can configure filters for specific user agents, expressions, and parameters. 

This can significantly reduce the time it takes to import your log file. It also allows you to focus your analysis on certain types of bots and real traffic. 

After clicking 'OK,' Screaming Frog should proceed to import and parse your log file. 

You may be required to specify your domain URL if it isn't already included. But this will only affect the URLs displayed within the log file report — not actual data like response codes, dates, file types, and URL extensions. 

Regardless, the import time depends on the size of your log file and the filters you set. 

3. Understanding the Overview Page 

Log File Analyser defaults to the overview page, which visualizes your log file data.

The main table summarizes insights like unique URLs per day, events, redirections, error codes, and more. You'll also discover timeline charts for response codes, URLs, and events per user agent. 

Observing the overview charts makes it easy to spot anomalies and identify trends in your ecommerce website's crawl events. Of course, it also reveals glaring issues in the form of error codes (4xx and 5xx responses). 

4. Analyzing Response Codes

Speaking of error codes, you can identify specific issues for individual pages in the 'Response Codes' tab. 

Feel free to look around and sort rows according to time, response code, URL, or number of events. 

If you're scanning for URLs with specific response codes, use the drop-down menu next to "Filter" in the upper-right corner. 

Select a URL to show more information, like the time of the last response and other response codes returned by the page. 

5. Analyze Page-Level Crawls

If you'd rather analyze crawling behavior on a page level, just go to the 'URLs' tab. 

This page organizes crawl events per page URL. You may also notice a lot of hits on non-essential URLs, like plugin requests, unused image assets, and invalid searches that may result in error codes. 

Regardless, you should keep your eyes peeled for error codes on valid, high-priority pages.

Aside from response codes, the URLs report section also tracks metrics like: 

• Event count per bot
• Average response time
• Content type
• Total size (bytes)

6. Identify SEO Opportunities

Log file analysis is good for one thing: providing in-depth crawlability insights that most ecommerce businesses often miss.

None of this matters if you don't know how to recognize optimization opportunities and take action. 

One of the first things you should do is address error codes and get indexation in full swing ASAP. Prioritize valuable page URLs and address the problem that prevents search engines from crawling them.

Next up, you need to make sure that search engines don't waste their crawl budget on non-essential pages. 

One approach is to modify your website's "robots.txt" file, which can easily block crawlers from accessing specific pages with a few lines of code. 

Don't forget to dig deeper and look at other factors that can affect SEO. 

For example, Screaming Frog's Log File Analyser can reveal correlations between page size, average response time, and content type. And, if you know a thing about modern SEO, you can't afford to overlook your Core Web Vitals if you want higher rankings. 

Looking at your referrers also lets you identify and double down on strategies that could boost the spread of search engine crawlers on your ecommerce site.

By using Log File Analyser and switching to the 'Referers' tab, you'll find link building (and internal linking) hotspots you can further leverage to improve the crawlability of important pages.

7. Monitor Changes and Iterate

In ecommerce SEO, success is built with small wins. 

That's why you should consistently monitor changes on your site either through an SEO platform like Ahrefs or ongoing log file analysis. 

By tracking crawler activity as you implement strategic SEO tactics, you'll be able to pinpoint what works and what doesn't. This is the key to creating an effective SEO strategy tailored to your ecommerce website's unique needs.  

Remember, the typical ecommerce website is in a constant state of flux. 

Users hop in and out of collections, product pages, and blog posts while exploring your online store. You're also constantly displaying dynamic content, launching special offers, and adjusting pages based on factors like stock levels. 

Just think about the work crawlers have to go through — and your responsibility to make sure they do their job well.

Additional Tools for Log File Analysis

SEO veterans trust Screaming Frog's Log File Analyser to dissect crawler activity on their ecommerce website. But, in order to make the most out of log file analysis, you shouldn't limit yourself to just one option.

Here are other tools you should consider:

• Semrush — Semrush comes with a built-in log file analysis tool that tracks crawl behavior, like frequency, user agents, and response codes.
• Splunk — An enterprise solution for large-scale analytics, real-time monitoring, and SEO log file analysis.
• Logz.io — As the name suggests, Logz.io is a dedicated log management platform, which can be used for visualizing and analyzing website access logs.

How Log File Analysis Can Directly Impact SEO for Ecommerce

Before we wrap things up, here's a recap of the direct benefits of log file analysis for ecommerce SEO:

• Improve Indexation: Optimize the crawlability of your revenue-generating pages, such as product and promo pages, to boost their visibility in search engines.
• Crawl Budget Optimization: Make sure search engine crawlers prioritize the pages that count — not pages they aren't supposed to index in the first place.
• Faster Error Resolution: Quickly underline crawl issues before they cause bigger SEO problems later on.
• Enhance Site Structure: Analyze and improve your website's internal link structure not just to increase crawlability, but also to enhance the user experience.
• Data-Driven Decision Making: Take the guesswork out of technical SEO and funnel your efforts into strategies that will lead to real results.

Conclusion 

Log file analysis is a powerful SEO tool for large ecommerce websites. 

It gives you access to insights that not many in the ecommerce industry have — a much-needed advantage in the highly competitive SEO landscape.

Sure, log file analysis may seem intimidating for non-technical website owners. But the payoff is definitely huge, especially since boosting crawlability also improves the effectiveness of your other SEO strategies. 

Besides, you can always count on turnkey solutions like Nostra's Crawler Optimization service. This will help you through the rough parts of technical SEO, particularly when it comes to creating significantly more crawler-friendly versions of your pages.

Click here to book a demo and see it in action.