CVLA3.2: CEFR-based Vocabulary Level Analyzer
CVLA assigns CEFR-J levels to words based on 8 textual features using the CEFR-J Wordlist. The level of the input text is determined based on 6 features, with the minimum and maximum values excluded to ensure stable results. For more details, please read our paper. If you have any questions or suggestions, please send your feedback via this form. CVLA2.0 is available here.
News
See earlier news
  • Mar 25, 2026: Listening monologue mode has been added to the top page, and CVLA has been updated to version 3.1.
  • May 6, 2025: The desktop version of CVLA3 has been developed and is now available as a beta release (please note it may take about 30 seconds to launch). Feel free to contact me if you notice anything unusual (kyudai.uchida.lab[at]gmail.com).
  • May 6, 2025: The CWLA, a tool for estimating CEFR-J levels in writing, is now available.
Correction to the AvrFreqRank equation and recalibration of the Listening mode (21 August 2026)

We have corrected an error in the regression coefficient that converts AvrFreqRank (average frequency rank) into CEFR units.

What was wrong. The correct coefficient derived from the calibration data is 0.010821 (intercept −2.802030), but the released version used 0.004493 (intercept −0.608127). As a result, AvrFreqRank was reported lower than it should have been, and it advanced by only 0.41 per CEFR level where the other seven measures advance by about 1.0.

Effect on the predicted level. CVLA3 predicts a level by discarding the highest and lowest of the eight measures and averaging the remaining six. The under-reported AvrFreqRank was the discarded minimum for about 40% of the texts in our validation data, so for those it had no effect on the predicted level at all. Overall accuracy is almost unchanged: on our development validation data, accuracy went from 65.7% to 63.0%, while agreement within one level improved from 99.1% to 100%. Individual texts can still change, however: the CEFR-J level changed for about a quarter of them.

When this matters to you. If you read the individual measures or their chart, AvrFreqRank will now appear higher than before. Many cases where vocabulary frequency looked lower than the other measures were an artefact of this error. Please take this into account when comparing per-measure results with earlier output. If you have results for a particular text from an earlier version, please re-run it rather than assuming the level is unchanged.

Recalibration of the Listening monologue mode. The listening adjustment had been derived from listening texts scored with the old coefficient, so it had to be re-derived. Version 3.1 added a fixed amount to the regression score (+0.6 when the score was 1 or below, +1.1 otherwise). Version 3.2 instead maps the listening score onto the reading scale with a linear transformation:

Adjusted score = 1.0897 × Regression score + 0.2876

This was fitted on level-graded listening and reading corpora (A1, A2, B1 and B2; 9,000–43,000 words per file) by regressing the score of each listening file onto the score of the reading file at the same CEFR level (r² = .967). All four listening files are assigned their correct level under the new equation. Listening results therefore differ from version 3.1, generally coming out lower, because the earlier adjustment was partly compensating for the under-reported AvrFreqRank. Reading results are not affected by this change.

We apologise for the inconvenience, and we welcome questions and reports via this form.


Text Input Mode
Tip: line breaks affect the result. Remove line breaks inside a paragraph (text copied from a PDF often has one at the end of every line), keep one line break between paragraphs, and avoid blank lines and double spaces. When you compare several texts, format them all the same way.

Word count: 0 Please enter between 10 and 1000 words.

Sample 1 (Simple Wikipedia) | Sample 2 (Center Exam 2018 Q3B-1) | Clear


File Mode
Files should be in UTF-8 format. Only .txt files are allowed. Maximum of 30 files, each up to 10KB. Tip: line breaks affect the result. Remove line breaks inside a paragraph (text copied from a PDF often has one at the end of every line), keep one line break between paragraphs, and avoid blank lines and double spaces. When you compare several texts, format them all the same way.

Papers

Uchida, S., & Negishi, M. (2018) Assigning CEFR-J levels to English texts based on textual features. In Y. Tono and H. Isahara (eds.) Proceedings of the 4th Asia Pacific Corpus Linguistics Conference (APCLC 2018), pp. 463-467. [PDF]
内田諭・根岸雅史(2021)「英語読解教材のCEFRレベルの推定 : CVLAの妥当性評価」Journal of Corpus-based Lexicology Studies, 3, pp.1-14. [Link]
Uchida S., & Negishi, M. (2025) Estimating the CEFR-J level of English reading passages: Development and accuracy of CVLA3『英語コーパス研究』(English Corpus Studies) 32. pp.165-174. https://doi.org/10.69193/ecs.32.0_165 [Link]

History

Aug 21, 2026: CVLA 3.2 released. Corrected the AvrFreqRank regression coefficient (0.004493 → 0.010821, intercept −0.608127 → −2.802030).
Aug 21, 2026: Recalibrated the Listening monologue adjustment to 1.0897 × score + 0.2876 (previously +0.6 / +1.1).
Aug 21, 2026: CVLA3 Desktop 3.2 released for Windows and macOS, with the same correction, the Reading/Listening monologue mode selector, and results aligned with the online version (identical values for all eight measures). Version 3.0 (2025) remains downloadable for reproducing earlier analyses.
Mar 25, 2026: CVLA 3.1 released. Added Reading/Listening monologue selector and listening-specific CEFR conversion adjustment.
May 7, 2025: The UI of this page has been updated.
May 6, 2025: The desktop version of CVLA3 (beta) released.
Feburary 9, 2025: CVLA 3.0 released.
October 23, 2024: CVLA 3.0 beta released.

Links
The desktop version of CVLA3
CVLA 2.0
CWLA (CEFR-based Writing Level Analyzer)
CEFR-J Project