Glossary

Your audit report uses technical terms from web performance, UX research, and content analysis. Here's what they all mean in plain language.

Audit Modules

AI Authenticity: This module analyzes sentence patterns, vocabulary choices, and writing style to identify markers commonly associated with AI-generated content. AI-sounding text can reduce trust and credibility with visitors.
AI SEO Readiness: Evaluates whether your content uses Schema markup, Q&A formatting, and semantic HTML that helps AI-powered search engines understand and surface your content in conversational results.
Brand Consistency: Compares color palettes across brand assets using perceptual color difference metrics (Delta E). Inconsistent branding reduces trust and makes your business look unprofessional.
Call-to-Action (CTA) Analysis: Identifies and evaluates call-to-action elements based on copy urgency, visual prominence, and placement. Weak CTAs are one of the most common reasons for low conversion rates.
Clarity & Jargon: Uses readability scores (like Flesch-Kincaid) and jargon detection to evaluate how accessible your content is to a general audience. Complex language increases bounce rates.
Cognitive Load: Combines visual clutter, information density, and layout complexity into a single score reflecting the mental effort required to process your page. Lower cognitive load means visitors can focus on what matters.
Color Palette: Extracts and displays the dominant colors found on your page for brand review.
Heuristic Audit: Tests your website against Nielsen's 10 usability heuristics and Shneiderman's eight golden rules — proven principles that predict how easy a site is to use.
Lexical Diversity: Uses advanced metrics (MATTR, MTLD, HD-D) that account for text length to measure vocabulary richness. Higher diversity keeps readers engaged and improves SEO.
Page Speed: Uses Google Lighthouse to measure Core Web Vitals and other performance metrics. Page speed directly impacts user experience, bounce rates, and search engine rankings.
Pricing Transparency: Detects psychological pricing tactics and evaluates how clearly pricing information is presented. Hidden or confusing pricing is one of the top reasons visitors abandon purchase decisions.
Semantic Coherence: Analyzes how well ideas connect logically using semantic similarity between adjacent sentences and paragraphs. Poor coherence means visitors get confused by disconnected or jumpy content.
Sentiment Analysis: Uses natural language processing to determine the emotional tone of your website copy. The right sentiment depends on context: consumer brands often benefit from positive tone, while B2B may prefer neutral or authoritative.
Syntactic Complexity: Analyzes grammatical dependencies between words to measure sentence complexity. Web users prefer short, simple sentences that can be quickly scanned.
Trust Signals: Scans your page for credibility indicators that help visitors trust your business: SSL certificates, privacy policies, testimonials, reviews, security badges, and visible contact information.
Value Proposition: Analyzes the balance between benefit-focused language and business jargon. A strong value proposition clearly communicates unique benefits with simple language and prominent placement.
Visual Attention (Saliency): Uses AI models to predict visual attention patterns, showing where users are most likely to look. This helps ensure your most important content (CTAs, value props) is in the visual hot spots.

Performance Metrics

Core Web Vitals: Core Web Vitals are LCP (loading speed), INP (responsiveness, replacing FID), and CLS (visual stability). Google uses 75th-percentile field data from the Chrome User Experience Report (CrUX) and rolls these into search ranking. To "pass" Core Web Vitals, all three must hit the "good" threshold for 75% of real visitors over the past 28 days.
Cumulative Layout Shift (CLS): CLS quantifies how much visible content moves around unexpectedly during page load. A score below 0.1 is considered good. High CLS causes users to accidentally click the wrong thing or lose their reading position.
DOM Size: DOM Size counts the total number of HTML elements on a page. A large DOM increases memory usage, makes style calculations slower, and can cause layout reflows. Under 1,500 elements is ideal.
First Contentful Paint (FCP): FCP marks the point when the browser renders the first piece of content from the DOM, giving the user visual feedback that the page is loading. Under 1.8 seconds is good. A fast FCP reassures users that something is happening.
First Input Delay (FID): FID captures the time from when a user first interacts with the page (e.g., clicking a link) to when the browser begins processing that interaction. Under 100ms is considered good. FID is being replaced by INP as the primary responsiveness metric.
Interaction to Next Paint (INP): INP measures the delay between a user interaction (click, tap, key press) and the next visual update on screen. Under 200ms feels instant. Slow INP makes your site feel laggy and unresponsive.
Largest Contentful Paint (LCP): LCP measures the time from when a user starts loading the page until the largest image or text block is rendered within the viewport. A good LCP is under 2.5 seconds. It directly impacts how fast your site feels and affects search rankings.
Lighthouse Accessibility score: Lighthouse runs a subset of the axe-core ruleset (color contrast, ARIA roles, alt text, form labels, landmarks, etc.) and reports the proportion that pass. A perfect score does not guarantee WCAG conformance — automated tools can only catch around a third of accessibility issues. Manual testing with a screen reader and keyboard is still required.
Lighthouse Performance score: Computed by Google Lighthouse from a weighted blend of FCP, Speed Index, LCP, TBT, and CLS measured in a controlled lab run. Above 90 is good, 50–89 is needs improvement, below 50 is poor. Lab-based, so it doesn't always match what real users experience — pair with Core Web Vitals field data for a complete view.
Lighthouse SEO score: Checks fundamentals like having a `<title>`, meta description, valid `lang` attribute, descriptive link text, mobile-friendly viewport, and a robots-friendly meta-robots tag. It does not measure ranking factors like backlinks, content quality, or topical authority — those live in tools like Search Console, Ahrefs, or Semrush.
Speed Index: Speed Index measures how quickly content is visually displayed during page load. It captures the overall perceived loading experience by looking at visual progress over time. Under 3.4 seconds is considered good.
Time to First Byte (TTFB): TTFB measures the time from when a user navigates to a URL until the first byte of data is received by the browser. It reflects server processing time and network latency. Under 600ms is good.
Total Blocking Time (TBT): TBT measures the total time between First Contentful Paint and Time to Interactive where the main thread was blocked long enough to prevent input responsiveness. Under 200ms is good. High TBT means the page feels sluggish.

Technical Concepts

Adjacent Coherence: How smoothly ideas flow from one paragraph to the next.
Alt text: Alt text should describe the image's purpose in context, not its appearance. Decorative images use alt="" so screen readers skip them. Functional images (icons that act as links/buttons) describe the action ("Search"), not the picture ("magnifying glass"). Missing or generic alt text is one of the most common accessibility failures.
ARIA: ARIA (Accessible Rich Internet Applications) lets you communicate semantics that the browser cannot infer — for example, that a `<div>` acts as a button, or that a region is currently expanded. The first rule of ARIA is "don't use ARIA": prefer native HTML elements (button, label, nav, main) and only reach for ARIA when no native element fits.
Cognitive Load Index: Combines multiple visual analysis factors into a single number representing the mental effort required to process a page. Lower is better — aim for pages that feel clean and focused rather than overwhelming.
Color Contrast: WCAG requires a contrast ratio of at least 4.5:1 for normal text and 3:1 for large text (18px+ or 14px+ bold). Low contrast makes text hard to read, especially for people with low vision or in bright environments like outdoor mobile use.
Color Shift (ΔE): Delta E (ΔE) is a standard measure of perceptual color difference. A ΔE under 1 is imperceptible; under 3 is barely noticeable; over 5 is clearly different. Used here to check if your brand colors are being used consistently.
Error Prevention: Nielsen's fifth usability heuristic. Using HTML attributes like "required," "pattern," and "maxlength" catches input errors before submission. Inline validation that checks as the user types is even better — it prevents the frustration of submitting a form only to see errors.
Global Coherence: How well the overall message holds together across the entire page.
HD-D Score: HD-D (Hypergeometric Distribution D) estimates the probability that a randomly selected word from the text is a unique type. It is robust to text length differences. Higher scores indicate richer vocabulary.
Heading Hierarchy: Screen readers let users jump between headings to scan page structure. If you skip from H2 to H4, that navigation breaks. Headings should reflect content structure, not visual styling — use CSS for size instead of picking heading levels for their appearance.
MATTR Score: MATTR (Moving-Average Type-Token Ratio) calculates the ratio of unique words to total words using a sliding window, making it fair for texts of different lengths. Higher scores mean more varied vocabulary.
MTLD Score: MTLD measures the average length of text sequences that maintain a certain level of vocabulary diversity. Higher MTLD means the writer uses more varied words before repeating.
Reading Ease: Based on the Flesch-Kincaid readability formula, which considers sentence length and syllable count. A score of 60-70 is considered ideal for web content (understandable by 13-15 year olds). Higher scores mean easier reading.
Semantic Load: How much meaning and information the page tries to communicate at once.
System Feedback: Nielsen's first usability heuristic: "Visibility of System Status." When users click a button, they need confirmation the system received their action. Without feedback (spinners, progress bars, success messages), users assume the system is frozen and click again or leave.
User Control & Freedom: Nielsen's third usability heuristic. Every modal should have a close button, every multi-step form should have a back button, and every action should be undoable when possible. Without escape hatches, users feel trapped and abandon the page.
Visual Clutter: The amount of competing visual elements on the page — less clutter means easier focus.
Visual Complexity: How visually busy the page is — more elements, colors, and movement means higher complexity.
WCAG: WCAG is published by the W3C and structured around four principles: content must be Perceivable, Operable, Understandable, and Robust (POUR). It defines three conformance levels: A, AA, and AAA. Most laws and contracts reference WCAG 2.1 or 2.2 at level AA.
WCAG AA: WCAG (Web Content Accessibility Guidelines) defines three levels: A (minimum), AA (recommended), and AAA (enhanced). Level AA covers the most impactful requirements including color contrast, keyboard navigation, text alternatives, and form labels. It is the legal standard in many jurisdictions.

Insights & Attribution

95% confidence interval: The CI is the range of plausible values for the true uplift, computed by re-running the synthetic-control fit against a placebo set (sites that did not get an audit) and reading off the 2.5th and 97.5th percentiles. If the interval includes zero, we cannot rule out "no real change" — that is reflected in the confidence tag. If the interval is entirely positive (or entirely negative) the direction of the change is statistically meaningful at the 95% level.
AI Overview exposure: We bucket each unique query in your last 90-day window into "AI-Overview-eligible" or "not", based on a rule-based heuristic: question prefixes (how, what, why, is, are, do, can, ...) and comparison shapes (" vs ", " or ", "best", "top", "review", "compare"). Sums of impressions and clicks on each bucket give the AIO impression share and the AIO vs non-AIO CTR. Google does not expose AIO eligibility per query — this is a coarse heuristic — but it tracks the surface-level signal well enough to flag where SERP-feature compression is most likely to bite.
Attribution coefficient: When you accumulate enough audits, we refit a model per audited metric (e.g., trust signals, clarity, page speed) that estimates how strongly each module's recommendations are associated with subsequent organic-search movement. Coefficients update as more audits land — they are descriptive of *your* historical pattern, not a universal claim, and are clamped to a sensible range so a single noisy audit does not dominate.
Average position (GSC): Average position is the impression-weighted mean rank across every query × URL × day in the window. It is not the position of any single result — a URL that ranked #1 on Monday and #10 on Tuesday averages to 5.5. Use position alongside clicks: a stable position with falling clicks usually means SERP features are taking the click, not that your ranking dropped.
Brand authority: We split your Search Console queries into "brand" (the query contains your domain's brand term) and "non-brand" buckets and report each bucket's share of clicks, impressions, and average position. A healthy site usually shows both: brand traffic confirms recall, non-brand traffic confirms reach. Sudden swings in the mix are often the leading indicator that something changed in the SERP.
Causal impact: Causal impact answers "did the audit move the needle?" rather than "did the metric change?" — those are not the same question. We fit a synthetic-control baseline to your pre-audit history, project it forward through the post-audit window, and report the gap between observed and projected as the audit's contribution. Confidence tags and the 95% CI describe how seriously to take the headline.
Click compression (YoY): We compare the most recent N-day window against the same window exactly one year ago, sourced from your daily Search Console totals. Impressions, clicks, and CTR deltas are reported as percentages of the prior window; the position delta is reported in absolute rank units (positive = worse — moved further from #1). The interesting story is when position is flat or improved and clicks are still down — SERP-feature compression eating clicks even though Google ranked you the same.
Confidence tags: Each metric carries a tag describing how much you should trust the headline number. "High" means the synthetic control fits your pre-audit data closely and the post-audit gap is large relative to noise. "Medium" means a meaningful gap with more uncertainty. "Low confidence" means the gap is small or the donor fit is loose. "Insufficient data" means we do not yet have enough post-audit history to compute a stable estimate. "Confounded" means we detected a parallel event (algorithm update, seasonality break, etc.) that makes attribution to your audit unsafe.
CTR compression vs non-AIO: Computed as 1 − (AIO CTR / non-AIO CTR), clamped to [0, 1]. A compression of 60% means clicks on AIO-eligible queries land at 40% of the rate they do on the rest of your queries. When this is high, no amount of on-page optimisation will lift those queries to non-AIO CTR — the SERP itself is the bottleneck. Knowing the ceiling helps decide where investment in featured-snippet content, FAQ schema, and entity markup is worth the work.
Donor pool (synthetic control): To estimate what would have happened without the audit, we build a "synthetic" version of your site from a weighted blend of similar sites that did not run an audit in the same period. The donor weights add up to 1.0 and reflect how closely each donor site tracked yours during the pre-audit window. When no donor pool is available, we fall back to a trend-and-seasonality baseline using only your own pre-audit history.
Headline derivation: Each insights card emits a structured "derivation" describing the question it answers, the answer in plain language, a severity (info / warn / critical) and a confidence tag. The page-level summary picks the top three, ranked by severity weighted by confidence, so a high-confidence "warn" outranks a low-confidence "critical." Cards that do not yet have data emit a derivation flagging that — they never silently disappear.
Organic clicks (GSC): Pulled directly from Google Search Console. Counts clicks on any URL on your verified property. Clicks are deduplicated within a session — multiple clicks from the same user on the same query within a short period collapse to one. This is the most concrete "did people actually visit" number Google publishes.
Organic CTR (GSC): CTR is clicks ÷ impressions for the time window, expressed as a percentage. There is no universal "good" CTR — it depends heavily on average position and SERP features. Compare your CTR over time and against your own non-AIO baseline rather than against industry benchmarks; the latter conflate query mix and brand strength.
Organic impressions (GSC): Pulled directly from Google Search Console. An impression is counted when a result link appears in a SERP and the user could plausibly see it (Google handles the visibility logic — pagination, AI Overview citations, etc.). Use impressions as the demand signal: if impressions are flat and clicks fall, the issue is CTR (often SERP-feature compression), not interest in your topic.
Pre / post windows: We compare two equal-length time windows: a pre-audit window ending the day before your audit ran, and a post-audit window starting the day after. Both windows are at least 28 days long when enough data is available, so day-of-week effects wash out and the trend is stable. The dates for the windows used in this report are shown in the headline impact card above.
Top movers: For each audit we rank queries by absolute change in clicks and impressions between the pre- and post-audit windows, surfacing the biggest gainers and losers. Combined with the causal-impact headline, this tells you not just whether the audit moved traffic, but which specific search queries drove the change.

Severity Levels

Critical: A serious issue that likely drives visitors away or prevents conversions. Fix first.
High: A significant issue that noticeably hurts user experience. Fix soon.
Low: A minor improvement opportunity — nice to fix but not urgent.
Medium: A moderate issue that could be improved for a better experience.

Score Bands

Critical (0–39): Significant problems that are likely hurting your business. Prioritize fixing these.
Good (70–100): This area of your site is performing well. Maintain it and focus efforts elsewhere.
Needs Attention (40–69): Room for improvement — addressing these issues will noticeably improve user experience.

Missing a term? Let us know and we'll add it.