SEO content analyzer for English text

How to use the content analyzer

Paste your article or page copy as plain text, as Markdown or as the HTML straight from your editor. The analyzer detects the format on its own. If you paste HTML you also get the heading structure (H1–H6), images missing alt text and the number of internal and external links. Then add your main keyword (it can be a phrase of two to four words) and, if you like, a few secondary ones. Results update as you type, and everything stays in your browser.

What the numbers mean

• Keyword density: how often the phrase appears compared with the total word count. There is no magic value. If the phrase shows up naturally in the introduction, in a heading and a few times in the body, that is plenty. Above roughly 3% the text starts to sound forced.
• Word variants: the tool also counts simple variants, so “optimize”, “optimizing” and “optimized” are related, as are singular and plural forms. It uses a light suffix-stripping rule rather than a full dictionary, so irregular forms (“mouse” and “mice”) are not matched.
• Flesch Reading Ease: a score from roughly 0 to 100 built from average sentence length and average syllables per word. Higher is easier. A score of about 60 to 70 is often called plain English, which suits most web copy for a general audience; specialist or technical writing usually scores lower, and that can be fine for the right readers.
• Flesch–Kincaid Grade: the same ingredients, expressed as an approximate US school grade. Because syllables are estimated, small differences between tools are normal.
• LIX: a readability index that does not depend on the language: average sentence length plus the percentage of long words (over six letters). Under 30 is very easy, 40 to 50 is medium, and above 60 is very difficult (these bands are rules of thumb).
• Phrases (n-grams): the most repeated words and two- or three-word combinations, without filler words. They show quickly what the text seems to be about, and whether you have repeated something too often.

English style checks, and their limits

Beyond readability, the analyzer flags a few habits that make English copy harder to read: heavy passive voice, long sentences, three or more sentences in a row that open with the same word, and weasel words (vague hedges and hype such as “very”, “basically” or “world-class”). These are rule-of-thumb heuristics, not grammar checking. Passive voice is sometimes the right choice, and a hedge is sometimes honest. Treat the flags as prompts to reread a sentence, not as errors.

Good practice for SEO content

• Answer the reader's main question in the first lines, then add detail. Start from what the person is trying to do, which we explain in our piece on search intent.
• Use one H1, H2s for the main sections and H3s for detail, without skipping levels. Our guide to the H1–H6 heading structure shows how.
• Keep paragraphs short (two to four sentences) and use lists for steps and enumerations.
• Write descriptive alt text for images and link to relevant pages with anchor text that says where the link goes, never “click here”.
• Put the keyword in the title, the introduction and one subheading, then write naturally. Choose phrases through proper keyword research, and preview the title and description with the SERP snippet simulator.

Common mistakes

Mechanically repeating the same phrase, long blocks of text with no subheadings, content copied from other sites, vague claims with no source, and pages that do not answer what the person searched for. A good score here is only a starting point: real quality comes from the author's expertise and experience, which is why trust signals matter too (see how to build E-E-A-T). If you want copy that is built to rank and persuade, take a look at our SEO content and copywriting service.