I built a free keyword density checker that runs entirely in the browser

If you write docs, landing pages, blog posts, or product copy, you’ve probably had this moment:

You finish a draft, read it back, and realize you may have repeated the same phrase way too many times.

Not because you were trying to game SEO.
Just because when you edit around the same topic for 30 minutes, repetition creeps in.

That’s why I built this free tool:
Keyword Density Checker

The goal wasn’t to make another “SEO hack” tool.

The goal was to create something simple that helps writers, devs, indie hackers, and marketers quickly answer questions like:

Am I overusing the same keyword?
Are my main phrases actually clear in the draft?
Which 2-word and 3-word phrases dominate this content?
Is this article balanced, or does it sound stuffed?
Why I built it

A lot of keyword tools feel bloated.

You paste content, wait on a server roundtrip, close popups, and dig through a UI that feels built for agencies instead of normal people trying to publish one clean article.

I wanted something faster and more practical:

paste text
click analyze
instantly see what terms and phrases repeat most
spot possible over-optimization before publishing

That’s it.

What it does

The checker analyzes:

single-word keywords
2-word phrases
3-word phrases

It also includes:

stop-word filtering
over-optimization warnings
CSV export
content stats like word count and read time
fully client-side processing, so your content stays in the browser

For me, the 2-word and 3-word phrase analysis is the most useful part.

Single-word counts alone don’t tell the whole story. A phrase like “keyword density checker” or “technical SEO audit” is often more meaningful than isolated word frequency.

Why client-side mattered

One thing I cared about from the start was privacy.

A lot of people want to check drafts that are not ready to be shared anywhere yet. Blog drafts, client copy, internal docs, product pages, proposal text — that stuff can be sensitive.

So I kept the analysis browser-side.

No signup. No upload flow. No unnecessary friction.

Who it’s for

I think this is useful for:

developers writing documentation
indie makers writing launch pages
bloggers editing drafts
SEO folks doing quick on-page checks
freelancers reviewing client content
anyone trying to reduce repetitive wording

It’s not meant to replace good writing.

It’s more like a fast diagnostic pass before you hit publish.

What I learned building it

A few things stood out while making this:

1. Simplicity is underrated

A focused tool that does one thing well is often more useful than an “all-in-one” dashboard.

1. Phrase-level analysis matters more than people think

Looking at 2-word and 3-word patterns gives much better signal than just raw word counts.

1. Speed changes behavior

When a tool is instant, people actually use it during editing instead of treating it like a chore.

1. Privacy can be a feature

Keeping processing in the browser makes the tool feel safer and more lightweight.

Try it

If you want to audit a draft, check phrase repetition, or catch possible keyword stuffing before publishing, here’s the tool:

👉 Free Keyword Density Checker

Would love feedback from other builders here, especially on the UX, phrase analysis, and any features you’d want next.