SEO Guide

SEO Audit Checklist
& How-To Guide

A systematic SEO audit checklist covering meta tags, structured data, Core Web Vitals, and internal links. Free 45-point audit — just enter your URL.

8 min read2026-05-15

An SEO audit is the systematic process of checking a website's technical settings, content structure, and user experience to ensure proper search engine evaluation. By examining approximately 45 items across 5 categories — meta tags, structured data, Core Web Vitals, internal links, and security — you can identify opportunities to improve search rankings.

What Is an SEO Audit?

An SEO audit is the process of identifying technical issues that hinder your website's search performance and clarifying improvement priorities. While audits cover technical SEO, content SEO, and external links, this guide focuses on the technical SEO diagnostics that site owners can execute themselves.

Why prioritize technical SEO? Because when the technical foundation is broken, other strategies (content improvement, backlink acquisition) can't take full effect. No matter how great your content is, if your site lacks HTTPS, Google's evaluation remains negative. The correct order is to fix the technical base first, then layer content strategies on top.

Google's Search Quality Evaluator Guidelines also establish that a page's E-E-A-T (Experience, Expertise, Authoritativeness, Trustworthiness) is built on technical trustworthiness. An SEO audit is the first step to making that technical foundation visible.

SEO Audit Checklist (6 Categories, 45 Items)

The following checklist covers the key technical SEO items. You can verify each one manually, but CodeQuest.work SEO automatically checks all items by simply entering a URL.

1

Meta Tags (title, description, OGP)

These elements appear directly in search results. Title tags are the most impactful on-page ranking factor, and descriptions influence CTR (click-through rate). OGP tags are essential for social media share previews.

  • Title tag is set (30–60 characters, includes target keyword)
  • Meta description is set (80–120 characters, includes call to action)
  • og:title / og:description / og:image are set
  • Twitter Card (twitter:card / twitter:image) is set
  • Viewport meta tag is set (mobile-friendliness)
2

Heading Structure (H1–H6)

Heading tags are critical signals for search engines to understand page topic structure. A broken hierarchy negatively impacts content relevance evaluation.

  • Exactly one h1 tag exists on the page
  • h1 includes the target keyword
  • Heading hierarchy follows logical h1→h2→h3 order
  • No heading level skips (e.g., jumping from h2 to h4)
3

Structured Data (JSON-LD)

Structured data is a prerequisite for rich results and contributes to higher citation rates in AI Overview (AIO). Google has indicated that AIO source selection references structured data.

  • Organization / WebSite schema is implemented
  • BreadcrumbList schema is implemented
  • Page-type-specific schema (Article / FAQPage / HowTo / Product, etc.)
  • No JSON-LD syntax errors (verified with Google Rich Results Test)
  • No missing required properties
4

Core Web Vitals (Speed & UX)

Core Web Vitals are official Google ranking factors. Failing LCP (loading speed), INP (interactivity), or CLS (layout stability) puts you at a disadvantage against competitors.

  • LCP (Largest Contentful Paint) ≤ 2.5 seconds
  • INP (Interaction to Next Paint) ≤ 200ms
  • CLS (Cumulative Layout Shift) ≤ 0.1
  • Images have width/height attributes set (CLS prevention)
  • Render-blocking resources are minimized
5

Internal Links & Site Structure

Internal links distribute PageRank within your site and determine crawler efficiency. Orphan pages (zero internal links) lead to indexing gaps.

  • No orphan pages (pages with no inbound internal links)
  • Important pages receive sufficient internal links
  • Anchor text accurately describes the linked page's content
  • No broken links (404 errors)
  • Canonical tags are correctly set
6

Security & Basic Setup

HTTPS is an official Google ranking factor. Mixed Content (HTTP/HTTPS resources) triggers browser warnings and increases bounce rates.

  • HTTPS is enabled (valid SSL certificate)
  • No Mixed Content (HTTP/HTTPS mixed loading)
  • robots.txt is properly configured
  • XML sitemap is in place
  • Favicon is set

Manually checking all 45 items above takes hours. With CodeQuest.work SEO, just enter a URL to automatically audit all items in seconds. Issues come with auto-generated fix code (JSON-LD, HTML meta tags).

4 Steps to Run a Free SEO Audit

Here's how to run an SEO audit with CodeQuest.work SEO. No registration required — start right away.

1

Enter URL and run the audit

Visit CodeQuest.work SEO and enter the URL you want to audit. The 45-point technical SEO audit completes in seconds. No registration required, completely free.

2

Review overall score and issues

You'll see a 100-point overall SEO score with pass/fail status for each category. Red items (failures) are your improvement priorities.

3

Copy fix code and implement

Failed items come with auto-generated fix code. Copy the JSON-LD structured data or HTML meta tags and paste them into your site.

4

Re-audit after fixes to verify improvement

After implementing fixes, run the audit again on the same URL to confirm score improvement. Paid plans include history tracking to monitor score trends over time.

How to Prioritize Improvements

When issues are found in your audit, improve them in the following priority order. Working from top to bottom yields maximum impact with minimum effort.

Critical

Security & Basic Setup

Missing HTTPS or misconfigured robots.txt affects overall search performance

High

Meta Tags (title, description)

Directly affects search result display and is easy to fix

High

Core Web Vitals

Official ranking factor. Directly impacts user experience

Medium

Heading Structure & Internal Links

Affects crawlability and content comprehension

Medium

Structured Data

Contributes to rich results and AIO citations. Moderate implementation effort

Common SEO Audit Mistakes

Chasing audit tool scores alone

SEO audit scores are guidelines, not goals. The objective isn't a perfect 100, but providing content that matches user search intent. Use scores to prioritize improvements, not as an end in themselves.

Only auditing the homepage

SEO issues often hide in subpages. Prioritize auditing blog posts and product pages — the pages that actually receive search traffic. Use site-wide diagnosis for efficient bulk checking.

Investing in content while ignoring technical SEO

When the technical foundation is broken (no HTTPS, failing Core Web Vitals, missing structured data), even great content struggles to perform. Fix the technical base before investing in content.

Auditing once and forgetting about it

SEO is an ongoing effort. CMS updates, plugin changes, and external factors (Google algorithm updates) constantly shift SEO conditions. Make monthly audits a habit.

SEO Audit Tools Compared

The best tool depends on your audit goals. Use CodeQuest.work SEO for comprehensive technical checks, GSC for actual performance data, and PageSpeed Insights for speed measurement.

CodeQuest.work SEO (this site)

Free 45-point technical SEO audit with auto-generated fix code.

Best for: Comprehensive technical SEO check & fix

Google Search Console

Primary data for indexing status, search performance, and backlinks. Official Google tool.

Best for: Verifying actual search performance data

PageSpeed Insights

Detailed Core Web Vitals measurement with both real user data (CrUX) and lab data.

Best for: In-depth page speed and UX analysis

Google Rich Results Test

Detects structured data syntax errors and missing required properties.

Best for: Structured data implementation verification

How to Audit Your Entire Site at Once

For sites with many pages, manually auditing one page at a time isn't practical. CodeQuest.work SEO's 'Site-wide Diagnosis' feature lets you audit all pages registered in your XML sitemap at once.

  • Enter your XML sitemap URL to automatically audit all pages
  • View per-page scores and issues in a single list
  • Download CSV for use as an improvement management list
  • Start improvements from the lowest-scoring pages first

Run Your Free SEO Audit Now

Enter a URL to instantly audit 45 items across meta tags, structured data, Core Web Vitals, internal links, and security. Auto-generates fix code for any issues found.

今井政和

Written by

今井政和

SEO Director / Frontend Developer

SEO Director with 20+ years of web industry experience. Creator of CodeQuest.work SEO and the official WordPress plugin "ORECTIC SEO CHECK." Author of a book on web strategy inspired by Edo-era merchant principles.

@imai_director

FAQ

How often should I run an SEO audit?
Monthly audits are ideal. Always run an additional audit after site redesigns or CMS updates. Core Web Vitals and indexing status can change due to external factors, making monthly monitoring the practical standard. CodeQuest.work SEO's history feature lets you track score trends over time.
If my SEO audit score is low, where should I start?
Prioritize technical SEO first (HTTPS, mobile-friendliness, Core Web Vitals). Improving content while the technical foundation is broken yields poor results. Next, fix meta tags (title, description), then move to structured data and internal links.
What's the difference between free and paid SEO audit tools?
Paid tools (Ahrefs, SEMrush, etc.) excel at backlink analysis, rank tracking, and competitor research. However, technical SEO audits (meta tags, structured data, Core Web Vitals, internal links) are well-covered by free tools. CodeQuest.work SEO offers a free 45-point technical audit plus auto-generated fix code for issues found.
What should I do if structured data errors are found in my audit?
Check the specific errors using Google's Rich Results Test, then fix them according to Schema.org specifications. Missing required properties is the most common error. CodeQuest.work SEO auto-generates JSON-LD implementation code for missing structured data, so you can fix issues with copy and paste.
Can I audit all pages on a large site?
Yes. CodeQuest.work SEO's 'Site-wide Diagnosis' feature audits all pages registered in your XML sitemap at once. No need to enter URLs one by one. Results are downloadable as CSV, letting you prioritize the pages that need the most improvement.