Lextutor
Lextutor, formally the Compleat Lexical Tutor, is Tom Cobb's web-based suite of vocabulary, corpus, and reading tools at https://www.lextutor.ca. It is the most widely cited free profiling and concordancing platform in ELT research and the default first stop for materials writers checking the lexical level of a draft text. Everything runs in the browser; nothing installs.
Core tools
VocabProfile is the headline routine. It runs a pasted text against a frequency list and returns coverage figures band by band, plus a colour-coded version of the text that marks each token by its band of origin. The English VocabProfile offers several list pairings: the classic K1+K2+AWL+off-list scheme inherited from West and Coxhead, the BNC-20 family lists, and the BNC/COCA 25K family lists prepared by Nation. VP-Compleat extends the same logic with additional list combinations and editable categories.
Beyond profiling, the suite includes a Concordance for KWIC searches against several corpora (Brown, BNC sampler, COCA samples, learner corpora), a Cloze Test Builder that auto-generates rational and Nth-word cloze items, a Family Lists browser, a Range comparator that contrasts two texts' lexical profiles, group lexical density and diversity calculators, and a host of teaching-oriented utilities (flashcards, hypertext readers, frequency-graded dictionaries).
Pedigree
Lextutor's profiling logic descends directly from the RANGE desktop tool released by Heatley, Nation, and Coxhead. Cobb adapted the algorithm for the web in the late 1990s and has maintained and extended the platform from the Université du Québec à Montréal since then. The 2007 Language Learning & Technology paper "Computing the vocabulary demands of L2 reading" sets out the methodology and remains the standard citation for profiling-based studies that use the site.
Why researchers use it
Three properties account for the platform's adoption. It is free and requires no install, lowering the barrier for student researchers and teacher-trainees. It supports multiple list combinations from a single interface, letting users compare profiles against different reference frames. And it pairs profiling with concordancing in one ecosystem, so a researcher who finds an interesting off-list token can immediately check its corpus behaviour without leaving the site.
The trade-offs are also stable. Pasted texts are processed on the server, which raises copyright and data-handling considerations for licensed material. List vintages drift, and reproducibility across years requires recording which list was used. And the interface is functional rather than polished, which favours users who already understand what a coverage figure means.
References
- Cobb, T. (n.d.). The Compleat Lexical Tutor. https://www.lextutor.ca
- Cobb, T. (2007). Computing the vocabulary demands of L2 reading. Language Learning & Technology, 11(3), 38–63. https://www.lltjournal.org/item/441/
- Heatley, A., Nation, I. S. P., & Coxhead, A. (2002). RANGE and Frequency programs. Victoria University of Wellington. https://www.wgtn.ac.nz/lals/resources/paul-nations-resources/vocabulary-analysis-programs
- Nation, I. S. P. (2013). Learning Vocabulary in Another Language (2nd ed.). Cambridge University Press.