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Text Analyzersentence complexity checker

Sentence Complexity Checker

Inspect sentence length and structural load so you can see whether a text feels difficult because of syntax, not just vocabulary.

FreeInstant resultNo upload needed
Measure average sentence length and long-sentence share.
Separate structural difficulty from lexical difficulty.
Use it to compare candidate books or chapters before building a deck.

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Paste text and watch the estimate update immediately.

Live analysis
Sentence structure looks dense. This sample averages 29.0 words per sentence, with 100% of sentences in the long range.
Sentence structure
Dense
Heuristic read on structural load rather than vocabulary level alone.
Average sentence length
29.0 words
Longer average sentences usually increase reading friction.
Longest sentence
29 words
Single very long sentences often create return-reading and parsing cost.
Long sentence share
100%
Sentences with 22+ words.

Takeaways

Even if the words are not all advanced, dense syntax alone can make this text feel tiring over several pages.

The sample does not rely heavily on extreme sentence length spikes.

This result leaned mostly on structure, not on explicit signal-word matches.

Matched signals

No strong signal words detected in this sample.

How to interpret this tool

Some texts feel tiring even when the words themselves are not extreme. The problem is often sentence structure: long clauses, delayed resolution, and too much parsing per line.

This checker isolates that structural layer so you can tell whether the passage is hard because of vocabulary, syntax, or both.

Usage notes

Treat short samples as directional only. The tool becomes more useful when the text reflects the real body of the book.
If vocabulary looks manageable but the text still feels hard, syntax or topic familiarity may be doing the damage.
Use the result to compare texts against each other, not to pretend the score is an official assessment.

FAQ

Can syntax make a text feel hard even if the words are common?

Yes. Long or nested sentences can raise reading cost even when the vocabulary itself is not especially advanced.

What counts as a long sentence here?

This tool treats 22 or more words as a long sentence. It is a heuristic threshold, not a formal linguistic boundary.

How should I use this with BookToAnki?

If structure is the main problem, more flashcards will not fully solve it. Choose a simpler text or treat the book as a stretch project.

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Pair good structure with selective extraction

Once the syntax looks manageable, keep the deck small so vocabulary review supports reading instead of replacing it.

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