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Semantic Highlight Map
Highlighted keyword zones will appear here as you type…
Four-pillar mathematical engine that processes your text in real-time — Shannon Entropy, Zipf-Mandelbrot distribution, Semantic Gravity, and KL Divergence. No AI chat, no server, no data stored.
Shannon H = — bits
Start typing to see your vocabulary richness score.
Zipf R² = —
Start typing to see your language naturalness score.
NPMI = —
Start typing to see how well your keywords cluster.
D_KL = — nats
Start typing to measure distance from ideal SEO distribution.
Analysis will appear here once you start typing…
Four steps from raw text to actionable SEO intelligence — entirely in your browser.
Type or paste any text. Wordy starts processing immediately — no submit button needed.
A Web Worker thread runs all four mathematical models in parallel, keeping the UI instantly responsive.
Four gauge dials update in real-time across Vocabulary, Naturalness, Focus, and SEO alignment.
The Recommendation card gives you a single, precise action to take — no jargon, no guesswork.
From first-time bloggers to enterprise SEO teams — if you care about keyword performance, Wordy gives you an edge.
Check keyword density before publishing. Avoid over-repetition that tanks readability scores while staying in the SEO sweet spot of 1–2.5%.
Audit existing pages for over-optimisation. The Zipf-Mandelbrot R² score flags artificially stuffed content before a manual review catches it.
Validate landing pages and ad copy in seconds. The KL Divergence score benchmarks your distribution against mathematically ideal SEO profiles.
Optimise product descriptions and category pages at scale. Paste any page copy and get an instant density report without leaving your workflow.
Maintain natural writing flow while ensuring key terms reach the threshold for topical relevance. The Semantic Gravity score shows if your main ideas cluster coherently.
Analyse academic papers and essays for term frequency. Shannon entropy scores give an objective measure of vocabulary depth and lexical diversity.
Everything you need to know about keyword density, SEO scoring, and how Wordy's engine works.
Keyword density is the percentage of times a target keyword appears relative to the total word count in a piece of content, calculated as D = (n / T) × 100. Search engines use it as one of many signals to assess topical relevance. A page with too few mentions of its target keyword may be seen as lacking focus; too many and it risks being flagged for over-optimisation or keyword stuffing. The goal is a natural, balanced distribution that reads well for humans while remaining statistically meaningful to algorithms.
The widely accepted safe range for a primary keyword is 1.0% to 2.5%. Between 2.6% and 3.5% is a caution zone — not an immediate penalty, but a signal to diversify phrasing. Above 3.6% significantly increases the risk of triggering over-optimisation filters. Secondary keywords and semantic synonyms should each stay below 2.5%. These thresholds are reflected in Wordy's colour-coded Safe (green), Warning (amber), and Danger (red) zones.
Shannon entropy, H(X) = −Σ P(xᵢ) log₂ P(xᵢ), measures the unpredictability — or information density — of a text's word distribution. A text that uses the same few words repeatedly has low entropy: it is highly predictable and statistically thin. Expert writing uses a rich, varied vocabulary that produces higher, more stable entropy. Wordy uses the normalised entropy (diversity score, 0–100%) as a proxy for vocabulary richness and content quality. Target: diversity above 65%.
All natural human language follows a precise power law: the most common word appears roughly twice as often as the second, three times the third, and so on. Mandelbrot extended Zipf's law with the formula f(k; q, s) = C / (k + q)ˢ, adding a shift parameter q that accounts for the "warm-up" zone of very high-frequency words. Wordy fits your actual word frequency distribution to this curve using OLS log-log regression and reports R². An R² close to 1.0 means your writing is statistically indistinguishable from natural prose. R² below 0.70 is a mathematical red flag for artificial keyword manipulation.
Semantic gravity measures how strongly your primary keywords cluster together in the text, using Normalised Pointwise Mutual Information (NPMI) — a probabilistic measure of co-occurrence within a sliding window. If your main topic words ("machine", "learning", "model") consistently appear near each other, the semantic gravity score is high, indicating strong topical coherence. Scattered keywords with no co-occurrence pattern produce a low gravity score, signalling that your content may lack a clear central theme — a factor modern NLP-based ranking systems consider.
Kullback-Leibler divergence, D_KL(P ‖ Q) = Σ P(i) log(P(i)/Q(i)), measures the statistical distance between your text's keyword distribution (P) and an ideal Zipf-shaped SEO baseline (Q) anchored at 1.8% peak density. A score close to 100% means your keyword hierarchy closely matches top-performing content patterns. A low score means your distribution is either too flat (no clear topic) or too steep (one keyword dominates). This pillar is Wordy's SEO benchmarking signal — it tells you how far you are from mathematical content perfection, independent of any specific algorithm.
Yes — Wordy is completely free with no signup, no account, and no usage limits. It is part of the RuntimeHub suite of browser-native tools built by Runtimezero. Since all computation happens locally in your browser, there is no cost per analysis and no server infrastructure to limit your usage.
No. Every word you type is processed entirely within a browser Web Worker thread on your device. No data is transmitted to any server, logged, stored, or shared. When you close or refresh the tab, all text is permanently discarded. Wordy cannot access your content — technically or legally.