Does PERF_NESTED_TABLES affect my score?

Yes. It is an importance 2 rule at RESEARCH confidence, so a failure costs 2 × 0.7 points of impact in the Performance category before that category is normalised to 100.

What does RESEARCH confidence mean?

Backed by large-sample study or industry research, not a specification. Confidence is a declared tier rather than a per-rule number, so every rule backed by the same class of evidence carries the same weight - which is what makes the score reproducible instead of hand-tuned.

How do I check PERF_NESTED_TABLES on my own site?

Paste your URL into the box above and it runs only this rule, usually in a couple of seconds. It is also included in the Performance checker and in a full scan.

PerformanceMedium Affects your score

No nested tables

PERF_NESTED_TABLES

Nested tables force repeated layout passes and are almost always a legacy layout artefact.

Free, no signupNo account, no card
No AI in the score986 deterministic rules
Nothing publishedYour scans stay yours
Answers in secondsQuick scan, no browser

How this rule is weighted

Importance: 2 / 10; How much this matters relative to other rules.
Confidence: RESEARCH; Backed by large-sample study or industry research, not a specification.
Severity: warning; How the finding is presented when it fails.
Scoring: Counts; A failure costs points in its category.

Impact is importance multiplied by the confidence tier’s weight — SPECIFICATION 1.0, RESEARCH 0.7, EMERGING 0.3, EXPERIMENTAL 0.1. Two rules backed by the same class of evidence therefore always carry the same weight, which is what makes the score reproducible rather than hand-tuned.

Questions about this rule

Does PERF_NESTED_TABLES affect my score?: Yes. It is an importance 2 rule at RESEARCH confidence, so a failure costs 2 × 0.7 points of impact in the Performance category before that category is normalised to 100.
What does RESEARCH confidence mean?: Backed by large-sample study or industry research, not a specification. Confidence is a declared tier rather than a per-rule number, so every rule backed by the same class of evidence carries the same weight - which is what makes the score reproducible instead of hand-tuned.
How do I check PERF_NESTED_TABLES on my own site?: Paste your URL into the box above and it runs only this rule, usually in a couple of seconds. It is also included in the Performance checker and in a full scan.

Related Performance rules

Run the Performance checker All 986 rules

No nested tables

How this rule is weighted

Questions about this rule

Tags

Related Performance rules

No nested tables

How this rule is weighted

Questions about this rule

Tags

Related Performance rules