On-page content checker is a free tool that gives you five checks in one place: length, keyword use, readability, heading structure and a clean URL slug. Paste an article or a page’s HTML and fix the page in one pass. This on-page content checker works as an H1 and heading checker, a keyword stuffing checker and a readability checker at the same time, and it replaces our separate word counter, keyword density checker, readability checker, heading checker and slug generator.
On-page content checker: test your text and headings
Summary
1. Length
2. Keyword use
3. Readability
4. Headings
5. URL slug
/How to use the On-Page Content Checker
- Type the main keyword you want the page to rank for. You can leave it empty if you only want length and readability.
- Paste your article into the on-page content checker as plain text, or paste the full HTML of a live page to include the heading check.
- Read the summary first. Red items hurt the page most, amber items are worth a second look.
- Fix the text in your editor, paste it again and check that the red items have gone.
What the on-page content checker looks at
- Length: words, characters, sentences, paragraphs and reading time at about 238 words a minute.
- Keyword use: how often your exact keyword appears, its density, whether it is in the first 100 words and in a heading, plus the words and phrases you repeat most.
- Readability: the Flesch reading ease score, a school grade level, long sentences and likely passive voice.
- Headings: the H1 to H6 outline of the page, missing or extra H1 tags, skipped levels and empty headings.
- URL slug: a short, lowercase slug built from your keyword or H1, without filler words.
What good looks like
There is no perfect number for any of these checks, so use the on-page content checker as a guide, not a target. A useful page answers the search fully, uses the keyword where it reads naturally, has one clear H1 with logical subheadings, and is easy to read on a phone. Common problems are a keyword that never appears in the H1 or first paragraph, more than one H1, and sentences long enough to lose readers on mobile.
What the on-page content checker tells you
The on-page content checker reviews the length of your text, how the keyword is used, how easy the writing is to read, how the headings are structured and what a clean URL slug could look like. It is a quick way to find the pages that need attention before a full audit.
It is most useful for writers and site owners who publish often and want a fast check before a page goes live.
How to act on the results
Start with the issues that hurt the page most: a missing H1, more than one H1, or a keyword that never appears in the first 100 words. Then review the body text for depth and clarity, because a checker can count words but cannot judge whether the answer is useful.
Run the check again after changes, and compare the results across similar pages to keep the whole site consistent.
Who should use an on-page content checker
Writers and editors can use an on-page content checker as a last step before publishing, to catch long sentences, a missing keyword in the first paragraph or a broken heading outline. Site owners can use it to review old pages that have lost traffic and decide which ones need a rewrite.
Agencies can paste a client page next to a competitor page and compare length, headings and keyword use, which shows quickly where a page is thin. Developers can paste the HTML of a template to confirm that every page type has exactly one H1 and a logical heading order.
A workflow for using the on-page content checker on a new page
First, write the page for the reader and decide on one main keyword. Paste the final HTML into the on-page content checker, with the keyword filled in, so the heading check and the keyword check both run.
Second, fix the red items in this order: heading problems, keyword missing from the first 100 words or a heading, then long sentences. Third, look at the most used words and two-word phrases. If one phrase dominates the list, replace some uses with related words, so the page reads naturally.
Last, copy the suggested slug, shorten it if needed, and publish. Check the page again after the next update to make sure the structure still holds.
Limits of the on-page content checker
No automated check can judge whether the content is accurate, helpful or written for the right audience. The score is a guide to structure and basic signals, not a promise of rankings. The final decision on quality should always come from a human who knows the topic and the customer.
Pros and cons
The on-page content checker reads your text and shows word count, keyword use, readability and headings, so you can improve a page before you publish it.
Pros
- Free and instant, so writers can check word count, headings and keyword use before publishing.
- Shows readability and keyword use in one view, which helps content stay on topic.
- Helps spot missing headings and overused phrases.
- Useful for any article, not only for SEO pages.
Cons
- A word count alone does not make content rank; the answer quality still matters most.
- Readability scores are a guide, not a rule, and technical topics often score lower.
- Keyword counts can encourage stuffing if taken too literally.
- The tool checks the text, not the page speed or links.
How to use the results well
Start with the main question your page answers. Then check that the headings cover the sub-questions a reader has.
Use the keyword count as a guide. The main keyword should appear naturally in the title, the first paragraph and one or two headings.
Check readability on the sections that matter most, such as the intro and the call to action.
What the checker does not show
It does not tell you search volume, competitors or backlinks. Use Search Console and a keyword tool for those.
Frequently asked questions
What is an on-page content checker?
An on-page content checker is a free tool that reads your text or page HTML and reports its length, keyword use, readability, heading structure and a clean URL slug, so you can fix a page before you publish it.
What is a good keyword density?
Google does not use a target density. Many SEOs treat roughly 0.5% to 2% for the exact phrase as natural, and above 3% usually reads as forced. Write for the reader and use related words.
Is my text saved anywhere?
No. The checks run in your browser and nothing is sent to our server.
Where did the word counter and other tools go?
They are all part of this checker now, so you can run every on-page check on one piece of content at once.
Want more than the on-page content checker?
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