TL;DR: The Problem with Percentage Scores
Google itself has criticised SEO audit percentage scores. In November 2025 guidance, Martin Splitt emphasised that technical audits should "prevent issues from interfering with crawling or indexing" rather than generating arbitrary numerical scores.
The problem is clear: a site can score 85% on an audit tool while having critical issues that prevent Google from indexing it. The percentage is worse than meaningless — it's actively misleading.
This post explains why percentage scores fail and introduces gate-based scoring as a better alternative.
What's Wrong with Percentage Scores?
The Equal Weighting Problem
Most SEO tools calculate scores by counting issues and dividing by total checks.
Example from a typical tool:
But this treats all issues as equal. A missing alt tag on a decorative image counts the same as a robots.txt that blocks Google entirely.
According to Search Engine Journal's analysis of Google's guidance, tools "tend to prioritize all issues equally and therefore make small issues appear more urgent than they are."
The Context Problem
Google's technical SEO guidance notes that what matters varies by site type:
| Issue | International Site | Local Blog | E-commerce | |-------|-------------------|------------|------------| | Hreflang errors | Critical | Irrelevant | Sometimes | | Duplicate content | Important | Minor | Critical | | Product schema | Irrelevant | Irrelevant | Critical | | 404 pages | Depends | Usually OK | Depends |
A percentage score can't capture this context. It flags hreflang errors on a local bakery's website as critical because the tool doesn't know it's irrelevant.
The False Positive Problem
Tools flag things that aren't actually problems:
As Google notes, "some flags, such as an increase in 404 error counts, can be merely indicative of normal site changes, such as the removal of content, and not an actual issue."
The Missing Issue Problem
While flagging harmless items, percentage tools often miss deeper problems:
The 85% score gives false confidence while real problems lurk beneath.
The Real-World Impact
Let me show you what this looks like in practice.
Case Study: The 92% Score with Zero Indexation
A client came to us with a "92% SEO score" from a popular tool. Their traffic had dropped 40% over six months.
The tool had flagged:
The tool had missed:
Result: 92% score, 40% traffic loss, zero useful diagnosis.
Case Study: The 67% Score That Was Actually Fine
Another client was panicked by a "67% score" on an audit tool.
The tool had flagged:
When we audited properly:
Result: 67% score, zero actual issues, wasted anxiety.
The Alternative: Gate-Based Scoring
Gate-based scoring recognises that some issues are foundational — they must pass before anything else matters.
The Three Gates
#### Critical Gate (Must ALL Pass) These are blocking issues. If any fails, the rest of the audit is secondary.
| Aspect | Why Critical | |--------|--------------| | SSL/HTTPS active | Trust, ranking signal | | Robots.txt not blocking | Basic accessibility | | Sitemap exists and valid | Discovery mechanism | | No Google penalties | Manual action present | | Content is indexable | JavaScript rendering works | | Index coverage >50% | Pages are actually indexed |
If any Critical aspect fails: Grade F regardless of other scores.
#### Essential Gate (>90% Must Pass) Important for performance but not complete blockers.
Examples: Core Web Vitals passing, mobile-friendly, canonical tags present, structured data valid, no severe duplicate content.
If Essential <90%: Cannot achieve Grade A or B.
#### Important Layer (Optimisation) Nice-to-haves that improve performance but don't break anything.
Examples: Optimal title lengths, image optimisation, internal linking depth, breadcrumb implementation.
The Resulting Grades
| Grade | Definition | |-------|------------| | A | Critical 100%, Essential >90%, Important >80% | | B | Critical 100%, Essential >90%, Important 60-80% | | C | Critical 100%, Essential 70-90% | | D | Critical 100%, Essential <70% | | F | Any Critical failure |
This creates meaningful differentiation. A site with Grade C has a clear path: fix Essential issues to reach B, then tackle Important for A.
Why This Matters for Different Audiences
For Agencies
Percentage scores create problems:
Gate-based scoring:
For In-House Teams
Percentage scores create problems:
Gate-based scoring:
For PE/VC Due Diligence
Percentage scores create problems:
Gate-based scoring:
Implementing Gate-Based Audits
Step 1: Define Your Critical Gate
Start with the aspects that truly break SEO if they fail:
Step 2: Define Your Essential Gate
These are important but not blocking:
Step 3: Create Your Scoring Framework
Build a simple matrix:
| Gate | Aspects | Pass Threshold | Weight | |------|---------|----------------|--------| | Critical | 11 | 100% | Blocking | | Essential | 22 | 90% | Required for A/B | | Important | 14 | 80% | Bonus |
Step 4: Communicate Clearly
Replace "your score is 73%" with:
*"Your site is Grade C. All critical aspects pass, meaning you have no blocking issues. However, you're only at 78% on Essential aspects — specifically Core Web Vitals and structured data. Fixing these would move you to Grade B. Important aspects are at 65%, which we'd address after Essential."*
This is actionable. A percentage isn't.
The Bottom Line
Percentage scores are a product of lazy automation. They count issues rather than assessing impact. They create false confidence or unnecessary panic. They don't help you prioritise.
Gate-based scoring reflects reality:
What to do:
The goal of an audit isn't a number — it's a diagnosis that leads to action.
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*Want a gate-based audit that actually tells you what matters? Get a ParadoxSEO audit with our 47-aspect health check and clear Grade-based scoring.*