What Is This Tool?
Keyword Scorer is a real-time, client-side mathematical inference engine that calculates the statistical density of every significant word in your text. It uses the classic density formula enriched with Shannon entropy modeling to give you a complete picture of your content's keyword distribution.
There is no server involved, no AI generating responses, and no data leaving your browser. Every calculation runs entirely in a Web Worker thread on your device — ensuring both privacy and near-zero latency.
The Mathematical Model
Beyond the core density formula, the tool computes Shannon entropy (H) across your keyword distribution. A high entropy score means your content has rich, diverse vocabulary — a low score indicates over-concentration on a narrow set of words, which modern search engines penalise as "over-optimisation".
The diversity index normalises entropy against the theoretical maximum for your vocabulary size, giving you an intuitive 0–100% score for lexical richness.
Alert Thresholds (Surgical Zones)
| Zone | Density Range | Meaning |
|---|---|---|
| Safe | 1.0% – 2.5% | Optimal keyword presence. Search engines read this as natural, topically focused writing. |
| Warning | 2.6% – 3.5% | Approaching over-optimisation. Consider introducing semantic synonyms to distribute weight. |
| Danger | > 3.6% | Over-optimisation territory. May trigger keyword stuffing filters in modern search algorithms. |
Why You Should Know How to Write Optimal Keywords
Signal Clarity
Search algorithms model your page's topical relevance as a probability distribution. A balanced keyword density makes your main topic statistically dominant without creating noise.
Semantic Richness
Modern NLP-based ranking systems reward high lexical entropy. Synonyms and related terms create a richer semantic field, improving contextual authority signals.
Penalty Avoidance
Keyword stuffing thresholds are probabilistic, not deterministic. Staying in the safe zone (1–2.5%) keeps your content statistically indistinguishable from natural language.
Reader Experience
Repetitive keywords degrade readability. Optimising density is not just about machines — it directly correlates with human engagement and dwell-time metrics.
Technical Architecture
The engine tokenises your input using a Unicode-aware regex that handles English text. Stop words are filtered against a curated English dictionary. Frequency analysis, density computation, highlight index generation, and entropy calculation all run in a dedicated Web Worker thread, keeping the main UI thread completely non-blocking.
Highlight positions are computed as exact character offsets, enabling the Semantic Map to mark word instances precisely. The debounce window is 120ms — fast enough to feel instantaneous while avoiding unnecessary computation mid-keystroke.
This tool is part of the RuntimeHub suite of developer and content tools by Runtimezero.