SEO Tool

SEO WRITING ASSISTANT

Write better content that ranks higher — real-time readability, SEO, and AI readiness analysis with actionable recommendations.

Private by design No signup · Free

Content

Paste or Type Your Content

Target Keyword (optional)

Structured Data (optional, for AI Readiness)

Paste JSON-LD structured data to check AI readiness completeness.

Words

Sentences

Reading

Chars

Unique

Avg Wd

Long Wd

Content Grade

—

0/100

Grade Level

—

Reading Ease

—

Avg Sentence

—

words

Long Sentences

>25 words

Fog Index

—

target 7-12

Sent. Types

—

Transition Words

0found

Recommendations

Enter content to see recommendations.

Frequently Asked Questions

What does the SEO Writing Assistant check?

The tool analyzes your content across 5 dimensions: Readability (Flesch-Kincaid, sentence length, transition words), SEO (keyword density, placement, word count), Structure (heading hierarchy, paragraph length), AI Readiness (entity density, extractable chunks, structured data), and Voice (passive voice, sentence variety).

Is my content sent to any server?

No. All analysis happens entirely in your browser. Your content never leaves your device — the tool works fully offline after the initial page load.

What is a good content grade?

A grade of B+ (80/100) or higher is publish-ready. Grades below C (65) have critical readability, structure, or SEO issues that should be addressed.

What is entity density and why does it matter for AI?

Entity density measures how many named entities (brands, dates, prices, metrics) appear in each paragraph. AI/LLM retrieval systems favor content with 4-7 entities per paragraph because it signals factual depth and verifiability.

What keyword density is ideal?

A natural keyword density of 0.5% to 2.5% is ideal. Below 0.5% and search engines may not clearly identify your topic. Above 3% risks over-optimization.

Which browsers does this work on?

All modern browsers including Chrome, Firefox, Safari and Edge on desktop and mobile. No install needed; the analyzer runs fully client-side after first load.

Is the SEO Writing Assistant free?

Yes, completely free with unlimited analyses, readability scoring, keyword density checks and content grades. No sign-up needed and everything runs locally in your browser.

How to Use

Paste or Type Your Content

Paste your article, blog post, or webpage content into the text area.

Enter Your Target Keyword

Type the primary keyword you want to rank for. The tool checks its placement across headings, first 100 words, and overall density.

Review the Content Grade

The tool computes an A-F readability and SEO grade in real time, with specific warnings and recommendations for each dimension.

Fix Issues

Use the detailed breakdown to fix long sentences, passive voice, heading skips, or low entity density.

Export the Report

Copy a summary of findings or the cleaned content back to your editor.

How to Calculate

Grades combine Flesch reading ease, grade level, keyword density, sentence-length spread, passive-voice share, and heading plus alt-text coverage. Fix the lowest sub-score first for the fastest grade lift.

About the SEO Writing Assistant

The SEO Writing Assistant is a free, private, browser-based tool that helps content creators, SEO professionals, and website owners write content that ranks higher in both traditional search engines and AI-powered answer engines.

Unlike generic readability checkers, this tool analyzes content across five modern scoring dimensions — Readability, SEO Optimization, Structure, AI/LLM Readiness, and Engagement/Voice — and produces a single A-F content grade with specific, actionable recommendations.

All processing happens in your browser. No sign-up, no data storage, no tracking.

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Methodology & feedback

Figures run locally in your browser from the values you enter (page updated 2026-10-02). Estimates are educational only — verify finance, tax and health decisions with a qualified professional (see Disclaimer). Spotted an error? Report it via contact and we correct with a new update date.

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