If the readability analysis gives you a red bullet for sentence length, you’re using long sentences too often. Click on the eye icon next to the check to see which of your sentences consist of more than 20 words. The SEO Onpage app will highlight these sentences for you. Go through these sentences, reread them and see which ones you can cut into 2 or maybe 3 sentences. It’s no problem if some sentences consist of more than 20 words, but try to keep the occurrence under 20%. Also, try to avoid using a long sentence after another long sentence. Try to mix longer and shorter sentences, this improves the readability of your text.