Readability Score

Compute Flesch-Kincaid, Gunning Fog, Coleman-Liau, SMOG, and ARI scores.

freeworks offlinenothing uploaded
Input
Output
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About readability score

Readability Score is a small tool that does one job while you watch. Nothing is saved, so a reload gives you a clean start.

There is no account and no upload step. Whatever you paste lives in a variable until you close the tab, and then it does not.

You will find it under Counters, alongside 5 other tools for the same sort of job.

Provides grade levels, reading ease, and word/sentence/syllable stats.

How to use it

01
Start it
Every control is on the tool itself. Keyboard shortcuts, where there are any, are listed beside it.
02
Watch it run
It updates in the page as you go. Nothing is sent anywhere, so it keeps working with the network off.
03
Close when done
Nothing is stored between visits. Reloading gives you a clean start rather than picking up where you left off.

Examples

Analyze article readability
Calculate readability scores for a paragraph
Input
The cat sat on the mat. It was a warm day. The sun was shining brightly in the clear blue sky.
Output
Flesch kincaid grade: 0.1
Gunning fog: 2.8
Coleman liau: 0
Automated readability: 0
Smog: 3.1
Average grade level: 1.2
Summary: Text is suitable for elementary school readers

FLESCH READING EASE
Score: 100
Level: Very Easy (5th grade)

STATS
Words: 21
Sentences: 3
Syllables: 23
Complex words: 0

Questions

Does Readability Score work offline?+

Yes. It is JavaScript running in this tab, so once the page has loaded it needs nothing further from the network. Put the machine in flight mode and it carries on. Nothing you do here is sent anywhere, because there is nowhere for it to go.

Does it remember anything between visits?+

No. Reload the page and it starts from nothing. There is no account, no saved state and no cookie holding your last session. That is a deliberate trade: it cannot lose your data because it never keeps any.

Is it accurate?+

Timing comes from performance.now(), the high resolution clock the browser provides, rather than from setInterval, which drifts by a few milliseconds every tick and compounds over minutes. What can still shift things is the browser throttling a tab in the background, so leave it visible if the timing matters.

Does it make a sound?+

Where a sound makes sense, it is generated with the Web Audio API rather than loaded as a file, so there is nothing to download and nothing to block. Browsers refuse to start audio until you have interacted with the page, which is why the first press is what switches it on.

Can I use Readability Score on a phone?+

Yes. The controls are sized for touch and the layout collapses to one column on a narrow screen. Bear in mind that a phone locking its screen will suspend the page, and timing stops with it.