ATOS Analyzer vs Text Inspector

ATOS Analyzer is a free web tool for estimating the readability level of text and books in English or Spanish. Users can enter a passage, analyze an entire book, or submit a sample with an estimated word count. Text can be typed or uploaded as a .txt, .docx, or .epub file, with uploads limited to 10 MB. The suggested passage length is 150 to 25,000 characters. Results include an ATOS level, grade-level equivalent, word count, AR Points, average word length, average sentence length, and language. ATOS estimates complexity on a grade-level scale using sentence length, word length, and word difficulty; its measure also accounts for book length. For a sampled book, Renaissance recommends three passages of about 150 words from different parts and an estimated total word count. Scanned documents need OCR to become recognized text before submission; changing a file extension does not convert them. The page includes a CCSS/ATOS grade-band chart for grades 1 through 12. Renaissance presents the measure as guidance for matching students with appropriately leveled reading material.

Text Inspector analyses English text for difficulty, readability, lexical diversity, and CEFR levels. Its overall difficulty score draws on more than 200 metrics, while the CEFR Level Checker gives individual words a level along with their commonness and difficulty. Listed tools include Statistics and Readability, Lexical Diversity, Scorecard, Tagger, EVP, BNC, COCA, Academic Word List and Phrases, Knowledge-Based Vocabulary Lists, and Metadiscourse Markers. An API lets people and organisations add analysis and scoring to their own products. The maker describes it as useful to language professionals, academics, and students preparing teaching materials or tests and evaluating student work. English is fully supported; other languages may receive limited statistics or lexical-diversity information. The Free plan covers 250 words and automatically deletes analysis data after six hours. The Organisation plan allows up to 13,000 words, the largest stated limit. A 30-day trial is listed for API access, which starts from £360 per year.