English-Corpora.org is a collection of large online English text databases — corpora — built and maintained by linguist Mark Davies at Brigham Young University. It is the most widely used set of free online English corpora in the world, with billions of words of searchable real English.

The site hosts more than 20 corpora, including the headline ones every linguist has heard of:

• COCA (Corpus of Contemporary American English) — 1.0 billion words, 1990–2019, balanced across genres.
• COHA (Corpus of Historical American English) — 475 million words, 1820–2019, balanced historical.
• NOW (News on the Web) — 20+ billion words, 20 countries, 2010–yesterday, web news.
• iWeb — 14 billion words, 6 countries, 2017, general web.
• GloWbE (Global Web-Based English) — 1.9 billion words, 20 countries, 2012–2013, web + blogs.
• TV / Movies / Soap corpora — 100M–325M words for spoken-style reference.
• Hansard, EEBO, Supreme Court, TIME, BNC, Strathy, CORE, Wikipedia, Coronavirus — specialized reference corpora.

The online interface is free to use for academic and personal research. Companies and academic groups can purchase Premium (individual) and Academic (group) licenses to download the raw data for their own servers.

English-Corpora.org is a research tool, not a lesson platform. Teachers use it in these specific ways:

• Verify a vocabulary claim: "Is make a decision really more common than take a decision in American English?" — a 5-second corpus query answers it with hard numbers.
• Build a frequency list for a level: pick a subcorpus (e.g., spoken American English), pull the top 1,000 words by frequency, and use it as a syllabus backbone.
• Check collocations and prepositions: "Which preposition follows interested?" — the collocates view shows in, by, and with ranked by frequency.
• Compare US vs. UK English: the compare-by-subcorpus view lets you put American and British side by side to decide which form to teach.
• Cite real examples in academic writing: advanced learners and grad students can pull authentic concordance lines to use as evidence in a research paper.
• Cross-check a publisher's word list: when a textbook says "these 500 words are A2," run the corpus against an A2 subcorpus to verify.

Yes — for what it is. English-Corpora.org is the standard reference corpus for English-language research, period. It is free at the point of use, well-maintained, and the data is cited by academia, lexicographers, and language-tech companies.

Where teachers need to set expectations: this is a research tool, not a learner-facing app. The interface is dense, the learning curve is steep, and the value comes from knowing what to query. If you are not already comfortable with the idea of a concordance line, expect to spend an hour with the help videos before the tool starts feeling useful.

Honest recommendation: bookmark English-Corpora.org as the reference resource to settle vocabulary, frequency, and collocation questions with real data. For everyday classroom teaching, pair it with a structured lesson-plan resource like ESL Brains or Teach-This — the corpus backs up your claims; the lesson plan delivers them to the class.