| Price from | — | $7.42/mo |
| Free plan | — | Yes |
| Free trial | Yes | — |
| Open source | — | — |
| Web | Yes | Yes |
| Windows | Yes | — |
| macOS | Yes | — |
| Linux | Yes | — |
| iOS | Yes | — |
| Android | Yes | — |
| API | Yes | Yes |
| Plans published | 7 | 8 |
| Spec score · Language learning apps | 9.3 (#3) | 8.8 (#27) |
| API authentication | The API requires project-specific API keys supplied as Bearer tokens in the Authorization header. | API requests use personal bearer tokens over HTTPS; third-party apps must not collect WaniKani passwords. |
| Company founding | SuperMemo World was founded on July 5, 1991 by Krzysztof Biedalak and Piotr Woźniak in Poznań. | LinkedIn lists Tofugu’s founding year as 2007. |
| Company size | LinkedIn lists SuperMemo World as a privately held e-learning company with 11–50 employees and 23 discoverable employees. | LinkedIn lists Tofugu as privately held with 11–50 employees. |
| Founded | 1991 | 2011 |
| Free plan | Yes | Yes |
| Headquarters | Poznań, Poland | Crunchbase lists Tofugu’s headquarters as Portland, Oregon, United States. |
| Languages offered | 25 | 1 |
| Licence | SuperMemo’s commercial algorithm implementations remain proprietary trade secrets rather than open-source software. | WaniKani’s service code and design are proprietary and copyright Tofugu; the service is not open source. |
| Mobile apps | Yes | WaniKani states that it currently has no official iOS or Android app; mobile apps mentioned in its help pages are made by users. |
| Notable news | SuperMemo announced its SM-20 API debut in 2026, allowing external products to embed its adaptive repetition engine. | A July 3, 2026 WaniKani blog post announced removal of Google Analytics as part of reducing third-party trackers. |
| Offline lessons | Yes | No |
| Personalized review | Yes | Yes |
| Rating on Trustpilot | 3.7 out of 5 from 1 review. | 3.5 out of 5 from 5 reviews |
| Spaced repetition | The scheduling algorithm selects individualized review intervals from a learner’s recall results and history. | The SRS adjusts the interval for each item using the learner’s previous session performance. |
