Technical SEO Audit | Server Log Analysis | Publishing Website
Investigating 404 Errors: A Technical SEO Audit Across 4,500+ URLs
What started as an investigation into unusual 404 errors became a broader technical SEO audit of a publishing website.
I analysed crawl data, server logs, and technical issues to identify potential causes, prioritise fixes, and provide actionable recommendations.
I analysed crawl data, server logs, and technical issues to identify potential causes, prioritise fixes, and provide actionable recommendations.
Project Overview
A publishing website was experiencing an unusual number of 404 errors. I was brought in to investigate the issue, examine the available technical evidence, and identify other SEO problems that needed attention.
PROJECT TYPE
Online Publishing
TIMELINE
December 2022
AUDIT SCOPE
4,544 URLs analysed
MY ROLE
Technical SEO Audit & Investigation
The Challenge: An Unusual Influx of 404 Errors
The website was experiencing an unusual influx of 404 errors, raising questions about where the requests were coming from and what might be causing them.
I investigated the issue using crawl data and server logs, working with the development team to examine suspicious request activity. The investigation also revealed an opportunity to assess other technical SEO issues affecting the website.
I investigated the issue using crawl data and server logs, working with the development team to examine suspicious request activity. The investigation also revealed an opportunity to assess other technical SEO issues affecting the website.
What the Audit Revealed
The investigation uncovered several technical SEO issues beyond the original 404 errors. Here are some of the key findings documented during the audit.
84
Broken internal links
4
Redirect chains
125
Missing meta descriptions
865
Images missing alt text
BEHIND THE AUDIT - How I Investigated the Issue
Following the Process
What began as an investigation into unusual 404 errors led me through crawl data, server logs, and a broader technical SEO audit. Here's how I approached the investigation.
- 02 - Server Log Investigation
- 03 - Broader Technical Audit
01 - Crawl Analysis
INVESTIGATION STAGE 01
Starting with the 404 errors
I used Screaming Frog SEO Spider to crawl 4,544 URLs, including 2,086 internal and 2,458 external URLs.
The crawl helped me identify broken internal links, redirect chains, and other technical issues requiring further investigation. I then reviewed the findings to understand which problems needed attention and document recommendations for the website team.
1 of 3 stages
Next stage →INVESTIGATION STAGE 02
Investigating the Server Logs
To investigate the unusual 404 activity further, I worked with the development team to obtain the website's server log files.
Analysing the logs helped me examine where the requests were coming from. I noticed that a significant portion of the suspicious activity was associated with a particular IP address.
This raised concerns about potentially malicious requests, although the evidence did not establish that the website had been hacked. I documented my findings and shared them with the website owner and development team for further security investigation.
2 of 3 stages
Next stage →INVESTIGATION STAGE 03
Expanding the Technical SEO Audit
After investigating the unusual 404 activity, I expanded the audit to assess other technical SEO issues affecting the publishing website.
Using Screaming Frog, Google Search Console, and PageSpeed Insights, I reviewed broken internal and external links, redirect chains, WordPress feed URLs, missing meta descriptions, image alt text, and page performance.
I documented the findings, identified areas requiring attention, and provided recommendations to help the website team prioritise technical improvements.
3 of 3 stages
Back to Stage 01Recommendations & Handover
Following the investigation, I documented the technical SEO findings and recommended fixes for the website team to review and prioritise. I also shared the suspicious server-request findings with the development team for further investigation.
Crawlability & Links
- Broken internal links: Recommended reviewing and fixing 84 broken internal links.
- Redirect chains: Recommended simplifying redirect chains.
- Broken external links: Recommended updating or removing links pointing to unavailable resources.
- WordPress feed URLs: Identified 195 feed URLs and recommended keeping them crawlable while preventing unwanted indexation.
On-Page SEO & Performance
- Missing meta descriptions: Identified 125 pages with missing meta descriptions and recommended prioritising important pages for optimisation.
- Image alt text: Identified 865 images missing alt text and recommended adding meaningful descriptions to informative images while avoiding unnecessary alt text on decorative images.
- Mobile performance: Flagged the mobile PageSpeed Insights score of 20 for further performance investigation and optimisation.
- Desktop performance: Documented the desktop PageSpeed Insights score of 75 and recommended reviewing the underlying performance opportunities.
Server Activity & Technical Follow-Up
I documented the unusual server-request activity identified during the investigation and shared the findings with the website owner and development team for further investigation. This ensured that potential security-related concerns were handed over to the team responsible for assessing and addressing them.
The Outcome
The project resulted in a documented technical SEO audit covering 4,544 URLs, with findings and recommendations to guide the website team's next steps.
Beyond identifying broken links, missing metadata, and performance issues, I provided guidance on which fixes to prioritise, recommended tools to make implementation more manageable, and shared technical findings requiring development-team involvement.
The investigation also helped distinguish SEO issues from potentially suspicious server activity, ensuring that the latter was escalated to the appropriate team for further investigation.
While I wasn't responsible for implementing the recommendations, the audit provided the website team with a clearer understanding of the issues and a practical starting point for addressing them.
Beyond identifying broken links, missing metadata, and performance issues, I provided guidance on which fixes to prioritise, recommended tools to make implementation more manageable, and shared technical findings requiring development-team involvement.
The investigation also helped distinguish SEO issues from potentially suspicious server activity, ensuring that the latter was escalated to the appropriate team for further investigation.
While I wasn't responsible for implementing the recommendations, the audit provided the website team with a clearer understanding of the issues and a practical starting point for addressing them.
Technical SEO Issues You Need Help Investigating?
Not sure what's causing those crawl errors, indexing issues, or other technical SEO problems? I can help you investigate what's happening, identify what needs attention, and recommend practical next steps your team can work with.