How is Server Log Analysis Important in Technical SEO

How is Server Log Analysis Important in Technical SEO
July 29, 2020

2 Min Read

Technical SEO plays a pivotal role in making your website easier to crawl and discoverable by search engines. It deals with technical aspects of a website such as XML sitemaps, structured data, page speed, robots.txt, etc. And the one true method to ace at technical SEO is going old school i.e. analyzing your log file. Moz says that your log files contain 100% accurate data in terms of how search engines crawl on your website.

But wait, what even is a log file? Many of you who are reading this right now might be new to this term or to technical SEO. So, let’s go through it step-by-step and address them all.

What are log files?

Log files or web server logs are a journal of outputs made by a web server containing ‘hits’ or records of all requests that the server has received. These requests can be from a visiting bot or a human. These log files consist of log entries that are automatically generated by computer servers, applications, or operating systems. 

What is log file analysis?

A log file analysis, simply put, is the thorough examination of the data of these log files usually for detecting malfunctions or problems. It can be for quality assurance(QA), network troubleshooting, security issues, and technical SEO. Yes, it is a crucial element of technical SEO or you can say, the foundation of technical SEO. Let’s look at the objectives it covers in technical SEO.

Purpose of log file analysis in technical SEO

There are multiple technical SEO issues that can be addressed via log file analysis. You can analyze a crawler’s patterns on your website and show you when, how frequently, and on what page the crawlers are present. Let’s look at some of its uses –

Bot Crawl Volume

It gives you the information on the number of requests made by search engines to your website over a given period of time. It also shows which search engine has crawled your website like GoogleBot, BingBot, Baidu, Yahoo, or Yandex.

Response code errors

It helps you detect status code errors like 4XX and 5XX which can badly affect your SEO. These need immediate and prompt rectification, therefore you need to be alert.

Crawl priority

Analyzing your logs reveals the pages which are not visited or crawled by bots regularly. For example, if GoogleBot crawls one of your website pages only once in 6 months, then you will miss the opportunity to rank for your target query for 6 months until Google comes to crawl it again. You can analyze it and set crawl priority for it in your XML sitemap or check your internal-linking structure.

Duplicate URL crawling

Additional URL parameters like filters or tracking for marketing purposes can result in search engines depleting your crawl budget and end up crawling up different pages with more or less the same content on your website. Click here to learn how to fix this issue by analyzing your log files.

Last crawl date

It gives you insight on when Google had last crawled a particular page on your website which you want to be indexed quickly.

Crawl budget waste

A crawl budget is assigned according to the number of pages that a search engine will crawl on your site in a specific period of time. It roughly depends on the authority of your domain and the flow of link share through your website.

This budget is often wasted on irrelevant pages like the old ones, duplicate pages, redirects, or the ones that are not important in your strategy. Thus, the budget gets exhausted on these and not the fresh & new content that you want to rank on search engines. Thus, you might want to keep a close watch on that with log analysis.

How do we perform log file analysis?

There are 3 principal methods through which you could do a log file analysis as enlisted by Moz

Completely manual way of doing it via Microsoft Excel

If you’re an Excel genius, this method is for you. You can export a batch of log files into Excel and do a basic analysis. Initially, you need to convert the log file into a .csv file because log files are basically text files. Click here for a comprehensive guide on how to do log analysis via Excel.

Open-source software like On-crawl ELK

Open-source log analyzers like OnCrawl ELK or ELK Stack have multiple functionalities and you could access them for free. Some highlights of OnCrawl ELK are that you can spot unique pages crawled by Google & monitor status codes which we know how important it is to keep on check, also it shows the crawl frequency and detects inactive and active pages on your website.

Small businesses mainly depend on these softwares which makes their job easier and is free.

Proprietary software of enterprise companies such as Screaming Frog, SEMrush, etc.

These are paid tools in the market which of course has additional features for efficient log analysis. Screaming Frog has been there for a very long time at a reasonable price and also had a free version of it. It has basically every functionality which is required for log file analysis. You can upload your files, analyze them, check your crawl budget, and whatnot.

But more importantly, we intend to talk about the latest state-of-the-art creation which has just come out of its beta version ie. SEMrush.

SEMrush as a proprietary tool for log analysis

SEMrush is quite a versatile tool and has been providing wide-ranging solutions that would satisfy all organic and paid marketing needs. The latest tool which has made it out of the beta version is the Log File Analyzer in its SEO toolkit.

Note: to make the best use of this article, you can try SEMrush FREE for 14 days and start analyzing your log files today!

How to use it?

Simply head to the SEO toolkit and click on ‘Log File Analyzer’ in the On-Page and Tech SEO section.

Next, you will see a screen where they will ask for your log file which you can upload from your system in the .log format.

Once you have dropped in your file you can proceed with your data analysis. There are multiple filters to choose from such as only Google bot analysis, device(desktop or smartphone), also the time period that you want to analyze.

The first part takes you to Googlebot activity which is a graphical representation that you can view in many ways such as  Googlebot hits with respect to status codes vs time, Hits wrt to file type of each page vs time, etc.

You can even select a path to track and filter data page wise which makes the job easier. Additionally, it gives you options to sort data according to the number of pages that have been crawled frequently, the number of bot hits, file type, and so on.


Log file analysis is a quintessential part of technical SEO that scrutinizes each and every misalignment in your SEO and helps you rank efficiently for your target query.

And with tools such as SEMrush, the job becomes a cakewalk! You can get a FREE trial and try it for yourself! 

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