Claude readability checker & score

Claude readability checker

What the Claude readability checker does

This app checks a Claude-drafted passage for how it actually reads: sentence length, paragraph density, an approximate grade level, and the sentences driving that estimate. It's tuned to a specific habit Claude's writing has, building long sentences from nested, qualifying clauses, which raises the reading level even when the vocabulary stays plain.

It runs as a server tool. Text you paste goes to our server to be read and described, and comes back with specifics attached. 5 free checks in any rolling 24 hours, no account required.

This is separate from grammar. Readability looks at sentence architecture; grammar looks at correctness. Use the app's Claude grammar checker when correctness is the actual question.

The problem

Where Claude's readability actually gets harder

Claude's vocabulary is usually plain. The reading level rises from sentence architecture instead, specifically from how many qualifying clauses get stacked into one sentence.

Front-loaded qualifiers

A caveat or exception arriving before the main claim, so a reader has to hold it in mind before reaching the point it modifies.

Nested subordinate clauses

Several qualifying clauses in one sentence, each extending the distance between the subject and its resolution.

Plain words, long sentences

A grade-level score driven by length rather than vocabulary, which a word-difficulty tool alone would miss entirely.

Delayed main point

The actual claim landing at the very end of a long sentence, after all its qualifications.

Stacked hedges

More than one caveat layered into a single sentence, each one adding another clause a reader has to carry forward.

Workflow

How to check a Claude draft's readability in three steps

Three steps, no prep work.

1. Paste the draft

Drop in the Claude text you're checking, up to 12,000 characters. A full passage gives a steadier read than one line.

2. Run the check

The text goes to our server once, gets read for structure and difficulty, and the description comes back to the page.

3. Split the long sentences

Start with the sentences named as longest or most nested, and split the qualifying clauses into their own sentences.

Why it matters

What this check shows that a word-difficulty tool can't

A word-difficulty check would tell a team Claude's vocabulary is fine, and stop there, missing the actual source of the reading difficulty. This check separates sentence length from vocabulary explicitly, naming the long, nested sentences responsible for a higher grade level.

That specificity changes the edit. Simplifying vocabulary in an already-plain sentence does nothing. Splitting a front-loaded qualifying clause into its own sentence is what actually brings the reading level down.

It also saves an editor from chasing the wrong fix. Without this separation, a team might spend time simplifying word choice in a passage where the words were never the problem to begin with.

How it's measured

Why Claude's sentences read harder than their words suggest

Claude is tuned toward completeness and nuance, which tends to mean stating a caveat before the main claim rather than adding it afterward as a separate sentence. That front-loading extends the distance a reader has to travel before reaching the point.

A reading-level formula weighs sentence length heavily alongside word difficulty, so a long sentence built from plain words can score higher than a shorter one using slightly harder vocabulary. This app reports the two separately so a team can see which one actually needs fixing.

Straight answer

Does a harder score mean the draft is worse?

No. A higher reading level from sentence length can reflect real nuance, not poor writing. Claude's qualifying clauses are often doing legitimate work that a shorter sentence would have to cut.

Match the target level to the audience instead of treating every high score as a defect. A technical or research audience may need exactly this structure; a general audience usually benefits from splitting it.

Who uses it

Who runs the Claude readability checker before publishing

Same check, different points in a workflow.

Content teams

Checking that a Claude-drafted piece hasn't crept into long, nested sentences for a general audience.

Research teams

Confirming a Claude-assisted summary reads at the level intended for its actual readers, not just correctly.

Educators

Matching Claude-assisted material to the reading level appropriate for a specific class.

Writers

Catching their own over-qualified sentences before publishing, especially ones that read fine on a fast pass.