Oanor Readability API vs Text Inspector

Oanor Readability API has no write-up on Specifiction yet; its figures are above.

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.