Keyword Research
Free keyword research tool: expand seed terms into hundreds of buyer-intent and question keywords with instant volume estimates, difficulty scores and CSV export. No signup.
Open →SEO & GEOZero-Token (Instant)
Free Keyword Density Checker & Readability Score Tool
Paste your content and see phrase-by-phrase density with over-optimisation warnings plus a Flesch Reading Ease score — all computed locally.
Why use this instead of doing it manually
Free keyword density checker: analyse any text for 1-word and 2-word phrase density, spot keyword stuffing, and get Flesch readability, word count and reading time instantly. No upload, no signup.
| Capability | The manual way | With ContentSERP |
|---|---|---|
| Density vs stuffing | Grep the word and guess | 1-gram + 2-gram density with a red over-optimisation flag |
| Readability | Separate browser tab | Flesch Reading Ease + FK grade inline with the density |
| Privacy | Paste copy into a cloud editor | Analysed on-device, nothing is uploaded |
| Export | Retype the numbers | One-click CSV with metrics and top phrases |
Frequently asked questions
What is a good keyword density?
There is no magic number — aim for natural usage, roughly 0.5–2.5%. The tool highlights any phrase above about 3% so you can spot over-optimisation before it reads as stuffing.
Which readability formula does it use?
The Flesch Reading Ease score and the Flesch–Kincaid grade level, computed from a deterministic syllable heuristic. For web copy, a Reading Ease of 60–70 is a good target.
Is my content uploaded anywhere?
No. Tokenising, counting and scoring all run in your browser, so your draft stays private.
Does it count stop words as keywords?
Common words (the, and, for…) are filtered from the top-keyword list so the results surface the phrases that actually matter for SEO.
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