Assessments for SEO and Readability
Overview
Kirby SEO Audit comes with 28 comprehensive assessments that analyze your content for search engine optimization and readability:
- 17 SEO assessments: Powered by Yoast SEO v3, focusing on keyword optimization, meta data, links, and technical SEO factors
- 8 Readability assessments: Powered by Yoast SEO v3, analyzing content structure, sentence length, and overall readability
- 3 Custom SEO assessments: Provided by Kirby SEO Audit to expand on Yoast SEO
Results are grouped into Good, OK, Bad, and Feedback, regardless of whether an assessment is SEO or readability – see Introduction for what each category means.
Complete Assessment List
Yoast SEO v3 Assessments
SEO Assessments (17)
| Assessment | Key | What It Checks |
|---|---|---|
| Introduction Keyword | introductionKeyword | Keyphrase appears in the first paragraph |
| Keyphrase Length | keyphraseLength | Keyphrase is not too short or long |
| Keyword Density | keyphraseDensity | Keyphrase frequency is optimal (not too low/high) |
| Meta Description Keyword | metaDescriptionKeyword | Keyphrase is present in meta description |
| Meta Description Length | metaDescriptionLength | Meta description is 120–156 characters |
| Subheadings Keyword | subheadingsKeyword | Keyphrase appears in H2–H6 headings |
| Text Competing Links | textCompetingLinks | No links compete with target keyphrase |
| Image Keyphrase | imageKeyphrase | Images contain keyphrase in alt/title attributes |
| Text Images | images | Content includes images |
| Text Length | textLength | Content meets minimum word count |
| Outbound Links | externalLinks | External links are present |
| Title Keyword | keyphraseInSEOTitle | Keyphrase appears in page title |
| Internal Links | internalLinks | Internal links are present |
| Page Title Width | titleWidth | Title fits in search results (~60 chars) |
| URL Keyword | slugKeyword | Keyphrase is in URL slug |
| Function Words | functionWordsInKeyphrase | Keyphrase contains content words (not just "the", "a") |
| Keyphrase Distribution | keyphraseDistribution | Keyphrase is evenly distributed throughout text |
Readability Assessments (8)
| Assessment | Key | What It Checks |
|---|---|---|
| Subheading Distribution | subheadingsTooLong | No text blocks exceed 300 words without a subheading |
| Paragraph Length | textParagraphTooLong | Paragraphs do not exceed 150 words |
| Sentence Length | textSentenceLength | At most 25% of sentences exceed 20 words |
| Transition Words | textTransitionWords | Content uses connective phrases |
| Passive Voice | passiveVoice | Passive voice is used sparingly |
| Text Presence | textPresence | Page contains text content |
| Sentence Beginnings | sentenceBeginnings | Sentences do not start the same way repeatedly |
| Word Complexity | wordComplexity | Vocabulary is not overly complex |
Kirby SEO Audit Custom Assessments (3)
| Assessment | Key | What It Checks |
|---|---|---|
| Single H1 | singleH1 | Exactly one H1 heading exists |
| Heading Structure | headingStructureOrder | H1–H6 headings follow sequential order (no skips like H1→H3) |
| Image Alt Attributes | altAttribute | All images have alt text |
Custom Assessment Selection
By default, all assessments are enabled. Pick which SEO and readability assessments to include in the report by adding an assessments property to your blueprint:
# Select the assessments you want to include
assessments:
- metaDescriptionKeyword
- metaDescriptionLength
- titleWidth
- images
- textLength
- imageKeyphrase
Wrap the snippet under buttons.seo-audit (view button) or under sections.<name> with type: seo-audit (section) – see Local Configuration for the full scaffolds.
Assessment suffix is ignored – titleWidth, titlewidth, and titleWidthAssessment all select the same check.Keyphrase-Dependent Assessments
The following SEO assessments require a keyphrase to be defined via keyphraseField or keyphrase:
functionWordsInKeyphraseintroductionKeywordkeyphraseDensitykeyphraseDistributionkeyphraseInSEOTitlekeyphraseLengthmetaDescriptionKeywordslugKeywordsubheadingsKeyword
If no keyphrase is provided, these assessments will be skipped unless explicitly enabled in the assessments property.
Language-Specific Features
Some assessments are only available in certain languages. The plugin uses the lang attribute of the rendered page's HTML for analysis, while the translations of the SEO results are based on the language selected in the Kirby Panel.
languages/xx.php file matches the ISO 639-1 language code (e.g., use de for German, not ger).| Assessment | Supported Languages |
|---|---|
wordComplexity | de, en, es, fr |
keyphraseDistribution | ar, cs, de, el, en, es, fr, he, hu, id, it, ja, nb, nl, pl, pt, ru, sk, sv, tr |
metaDescriptionLength | ar, cs, de, el, en, es, fa, fr, he, hu, id, it, ja, nb, nl, pl, pt, ru, sk, sv, tr |
textParagraphTooLong | ar, cs, de, el, en, es, fa, fr, he, hu, id, it, ja, nb, nl, pl, pt, ru, sk, sv, tr |
textSentenceLength | ar, cs, de, el, en, es, fa, fr, he, hu, id, it, ja, nb, nl, pl, pt, ru, sk, sv, tr |
passiveVoice | ar, cs, de, el, en, es, fa, fr, he, hu, id, it, nb, nl, pl, pt, ru, sk, sv, tr |
textTransitionWords | ar, ca, cs, de, el, en, es, fa, fr, he, hu, id, it, ja, nb, nl, pl, pt, ru, sk, sv, tr |
functionWordsInKeyphrase | ar, cs, de, el, en, es, fa, fr, he, hu, id, it, ja, nb, nl, pl, pt, ru, sk, sv, tr |
Norwegian is listed as nb, the code the analysis ships its researcher under. A page marked no or nn resolves to it, so all three write their own language.
assessments list configured, an assessment that does not support your content's language is skipped silently. List it explicitly and the analysis aborts with an error naming the languages that assessment supports.