Readability Checker

How it works

Paste text, get a score from 0 to 100. Higher means easier to read. The tool detects the language from the text itself: English gets the original Flesch Reading Ease formula, German gets Toni Amstad's adaptation, because German words carry more syllables and the original formula would rate every German text as academic prose.

Both formulas only look at two things: average sentence length and average syllables per word. That's the whole trick. Syllables are counted with a heuristic (vowel groups, language-specific rules for silent e and diphthongs), which is accurate enough for scoring, though it will miscount the occasional word.

The most useful part is probably the bottom list: your five longest sentences. If the score is bad, that's where it comes from.

When to use it

• Checking a blog draft before publishing. I aim for 60+ in German web copy; below 50 means I start splitting sentences.
• Comparing two versions of the same paragraph after an edit.
• Making the "this reads like a legal document" feedback measurable.

What the score doesn't measure

Whether the text is any good. You can score 90 with content-free filler, and some genuinely clear technical writing sits at 45 because the terminology is long. The score measures sentence mechanics, nothing else. Use it as a smoke detector, not as a judge.