A keyword extractor is a text analysis tool that identifies the most relevant and frequently occurring words or phrases in a given text. Our tool uses a term frequency (TF) approach: it splits the text into individual words, filters out common stop words (like "the", "and", "is"), counts how often each word appears, and ranks them by frequency. The weight percentage shows each keyword's share of the total word count, giving you a clear picture of which terms dominate your content.

Stop words are common function words that carry little semantic meaning on their own — such as the, a, an, in, on, at, is, are, was, of, to, for, with, and, but, or, it, that, this, these, those, and many more. Our built-in stop word list contains over 150 English stop words, including pronouns, prepositions, conjunctions, and auxiliary verbs. Filtering them out ensures the keywords you extract are actually meaningful content words rather than grammatical glue.

Keyword extraction is a powerful SEO tool. By analyzing your content (or a competitor's), you can: (1) identify which terms you're naturally ranking for, (2) ensure your target keywords appear with sufficient frequency, (3) discover unexpected keyword opportunities, (4) check keyword density to avoid over-optimization penalties, and (5) compare your keyword profile against top-performing competitor pages. Use the extracted list to refine meta tags, headings, and body content strategically.

Word frequency (TF) simply counts how many times a word appears in a single document — this is what our tool calculates. TF-IDF (Term Frequency-Inverse Document Frequency) goes further by comparing a word's frequency in one document against its frequency across a whole collection of documents. This helps identify words that are uniquely important to a specific document, not just common everywhere. For single-document analysis, pure frequency is fast, intuitive, and effective. For comparing multiple documents, TF-IDF provides deeper insight.

Yes! Use the Extra Exclusions field in the settings bar to enter any additional words you want to exclude — separate them with commas. This is useful when your text contains domain-specific filler words, brand names you want to ignore, or any terms that aren't meaningful for your analysis. These exclusions are applied on top of the built-in stop word filter.

While there's no single "perfect" keyword density, most SEO experts recommend keeping your primary keyword's density between 0.5% and 2.5% of total word count. Higher than 3% may trigger search engine spam filters (keyword stuffing). Our tool displays the weight percentage for each keyword, making it easy to spot over-optimization. Aim for natural, readable content where keywords appear organically rather than forced.

Our keyword extractor is optimized for English text, including handling of contractions (don't, it's, we're) and hyphenated words. The built-in stop word list is English-specific. However, the word-splitting algorithm uses Unicode-aware boundaries, so it can process text in other Latin-alphabet languages like Spanish, French, German, or Italian reasonably well — just note that the stop word filter won't be as effective for non-English content. For best results with non-English text, we recommend adding language-specific stop words via the Extra Exclusions field.

Absolutely secure. All text processing happens entirely in your browser using client-side JavaScript. No data is ever sent to any server, uploaded, stored, or logged. You can safely analyze sensitive or confidential documents — your text never leaves your device. This also means the tool works offline once the page has loaded.