Clozemaster
Clozemaster is a language learning platform that uses cloze deletion (fill-in-the-blank) exercises to teach vocabulary and grammar through context. Supporting over 100 languages with content sourced from the open Tatoeba database, it offers a gamified approach focused on high-volume sentence repetition.
Score generated by AI agents based on publicly cited evidence and reviewed by the project maintainer. Not independently validated.
Score History
Timeline events are AI-curated from public reporting. Score trajectory is derived from documented events.
Clozemaster launched in early 2016 as a completely free side project by founder Mike, built on the open-source Tatoeba sentence database. All features were unrestricted with no monetization layer. The only notable concern was minimal lock-in from the gamification system (points, streaks) and the absence of data export for learning progress.
Clozemaster introduced Pro subscriptions at $8/month or $60/year, gating features like custom collections, grammar challenges, and advanced SRS customization behind a paywall. The core cloze-deletion practice remained free and unlimited. The freemium split introduced mild lock-in through Pro-only features and created light upsell friction, but monetization was restrained with a lifetime purchase option available.
Clozemaster expanded significantly with Cloze-Listening, Radio Mode, Grammar Challenges, and a major collections overhaul. Many new features were Pro-exclusive, deepening the freemium divide. The platform grew to support 170+ language pairs. Lock-in increased as invested users accumulated progress across more feature types. The privacy policy disclosed third-party advertising network data sharing, though no ads appeared in the product itself.
The August 2022 imposition of a 30-sentence daily limit for free users was Clozemaster's most significant enshittification event, fundamentally changing the product from unlimited-free-with-Pro-extras to a hard-capped trial. The limit was widely criticized as too restrictive for a method built on high-volume repetition. A 50% discount code was offered to existing users, and the forum was restricted to Pro users only for posting. Pricing remained at $8/month, $60/year, $140 lifetime.
Clozemaster has stabilized as a freemium product with modest enshittification. New features like AI-powered sentence explanations and revamped Fast Track collections added value, but the Cloze-Listening spinoff to Common Ear and persistent bugs in Hands-Free Mode offset these gains. Pricing continued to creep upward, and progress data remains non-exportable despite user requests.
Alternatives
Free and open-source spaced repetition flashcard program with a massive library of community-made decks for virtually every language. Highly configurable and supports cloze deletion natively — so you can replicate Clozemaster's core method entirely. Steeper learning curve than Clozemaster's web interface, but unlimited free usage, offline support, and complete data portability. The AnkiWeb sync is free; mobile apps are free on Android (AnkiDroid) and a one-time $24.99 on iOS.
The most popular language learning app with gamified lessons, a large user community, and a free tier with ads. Best for beginners and intermediate learners building vocabulary and basic grammar — less suited for the high-volume advanced sentence practice that Clozemaster specializes in. Many learners use both: Duolingo for structure and Clozemaster for high-volume vocabulary drilling. Easy switch for casual learners.
Dimensional Breakdown
Summaries below were written by AI agents based on the cited evidence. They are editorial interpretations, not independent research findings.
Dimension History
Timeline (31 events)
Clozemaster Launches as Free Web-Based Side Project
Founder Mike launched Clozemaster as a free side project built on the open-source Tatoeba sentence database. The platform used cloze-deletion exercises to help language learners drill vocabulary in context, positioning itself as a 'post-Duolingo' tool for intermediate and advanced learners. All features were completely free with no usage limits.
Clozemaster iOS Mobile App Released
Language Innovation LLC published the Clozemaster iOS app on the Apple App Store, expanding the platform beyond web-only access. The Android app followed shortly after. Mobile apps provided offline access to some features but lacked full feature parity with the web version, a gap that persists to this day.
Clozemaster Featured on Hacker News Show HN
Founder Mike posted Clozemaster as a Show HN on Hacker News, introducing the platform to the tech community. At that point the site had been running for 'just under a year' with support for over 50 languages, mobile apps, and thousands of users. The post generated significant interest and discussion about the cloze-deletion learning methodology.
Custom Cloze-Collections Launched as Pro Beta Feature
Clozemaster introduced custom cloze-collections in beta for Pro subscribers, allowing users to create personalized sentence sets via manual input, file upload (CSV/TSV), or by selecting from existing Clozemaster content. This was one of the first significant features gated behind the Pro subscription, establishing the freemium model.
Grammar Challenges Feature Added for Pro Users
Clozemaster introduced Grammar Challenges for over 30 language pairings, offering fill-in-the-blank exercises focused on specific grammar points including prepositions, pronouns, and verb conjugations across indicative, subjunctive, and conditional moods. Like custom collections, this feature was gated behind Pro subscription.
Volunteer Moderator System Announced for Content Curation
Mike announced plans to contact community volunteers to serve as language-specific moderators, including named contributors for French and German. The moderator program aimed to help resolve reported sentence errors more efficiently, addressing a persistent quality concern with the Tatoeba-sourced content.
Major Platform Update Reorganizes Collections and Expands Pro Features
Clozemaster released a significant update reorganizing all content around collections, enabling collection-level review, favorites, and search. Pro users gained the ability to edit sentence translations, add notes and hints, customize mastery percentages, and download all collections for offline mobile use. Cloze-Listening expanded to 30+ languages for all Clozemaster-created collections.
Radio Mode Launched for Hands-Free Passive Listening
Clozemaster introduced Radio Mode in mobile app version 2.7, enabling hands-free passive listening practice. The feature played sentence audio with pauses for translation and repetition, allowing learners to practice while multitasking. It included a sleep timer and was available as a beta feature for Pro subscribers.
Cloze-Listening Beta Feature Launched
Clozemaster introduced Cloze-Listening as a beta feature, allowing learners to hear sentences recorded by native speakers and fill in missing words by ear. Initial availability included Spanish, French, German, Italian, and Russian from English, with 1,000 sentences per language pair. The feature used real native speaker audio with varying accents.
Points System and Leaderboard Changes Discussed
The Clozemaster community discussed proposed changes to the points system and leaderboards, which drove engagement through weekly, monthly, and all-time rankings. The gamification system including streaks, daily point goals, levels, and competitive leaderboards created soft lock-in by making accumulated progress non-transferable to competing platforms.
Community Encouraged to Contribute to Tatoeba Database
Clozemaster promoted community contributions to the Tatoeba open-source sentence database that underpins its platform. This highlighted the symbiotic relationship where Clozemaster builds commercial value on volunteer-curated Creative Commons content, while also helping improve the underlying database that remains freely available to anyone.
Free Tier Restricted to 30 Sentences Per Day Per Language
Clozemaster announced that free accounts would be limited to 30 sentences per day per language, effective August 14, 2022. Previously, free users had unlimited access to sentence practice. The company offered existing users a 50% discount code (CMPRO22) valid until August 13. The change was widely criticized as too aggressive for a cloze-deletion method that relies on high-volume repetition. Users on the forum noted that zero non-Pro users appeared in the top 10 leaderboard after implementation.
User Documents Free Tier Frustration After Limit Change
A Medium article by Dalandan Studio documented the frustration of being a free Clozemaster user after the 30-sentence daily limit, calculating it would take over 7 years to work through all sentences even without mistakes. The article highlighted how the limit fundamentally changed the platform's value proposition for non-paying users.
Users Request CSV Export for Learning Progress Data
Forum users requested the ability to export words and progress data from collections to CSV or Excel format. Despite the request, Clozemaster has not implemented a progress export feature. While users can import content via CSV upload (Pro only), there remains no way to export accumulated learning progress, SRS schedules, or mastery data to portable formats.
Italian Course Reported to Have Large Number of Cloze Errors
Users reported a significant number of errors in the Italian course sentences, including inaccurate translations and mismatched cloze entries. This highlighted ongoing quality issues with the Tatoeba-sourced content, where crowd-sourced translations can contain errors that persist without dedicated curation for less-popular languages.
Early ChatGPT Explain Feature Reports Incorrect Explanations
Shortly after Clozemaster introduced ChatGPT-powered sentence explanations, users began reporting that the feature produced incorrect explanations. Reports included wrong grammatical analysis, factual errors about word origins, and misleading information particularly for less-common languages where the AI model had less training data.
Lifetime Pro Subscription Discounted to $98 on SlickDeals
Clozemaster offered a 30% discount on all Pro plans, bringing the lifetime subscription from $140 to $98. The deal was tracked on SlickDeals, highlighting that the company periodically ran deep discounts to drive conversions. The availability of a lifetime option remains a positive counter to subscription-only monetization models.
Duolingo Forum Users Describe Clozemaster as Very Pushy to Upgrade
Users on the Duolingo Forum (Duome) discussed Clozemaster's Pro upgrade prompts, describing the app as 'very pushy to PRO.' While not as aggressive as dark patterns used by larger platforms, the sentiment reflected frustration with the frequency of upsell prompts shown to free users within the app interface.
Dashboard Stats and Calendar Features Updated
Clozemaster version 2.9.5 added toggleable dashboard stats showing played today, new, and review counts per collection. The calendar stats feature was restored after being previously removed. These quality-of-life improvements enhanced visibility into learning progress for active users.
Duolingo Mothballs Welsh Language Course
Duolingo announced it would pause updates to its Welsh language course from November 2023, channeling resources toward higher-demand languages like Spanish and French. This created an opportunity for Clozemaster to expand Welsh content and fill the gap left by the market leader's retreat from minority languages.
Developer Builds DIY Clozemaster Alternative Using Open Tatoeba Data
Software developer Fernando Borretti published a detailed blog post explaining how to build a Clozemaster-like tool using Tatoeba's freely downloadable Creative Commons sentence data. The post demonstrated that Clozemaster's core content is not proprietary, as anyone can replicate the cloze-deletion experience using the same open dataset, mitigating lock-in concerns.
Hands-Free Mode Stuttering and Crashing Reported
Multiple users reported persistent stuttering and crashes in Clozemaster's Hands-Free Mode, particularly on Android devices. The bug affected a key usability feature for learners who practiced while driving or exercising. Despite forum reports, the issue persisted for months without a fix, reflecting the small team's limited capacity for bug resolution.
New Fast Track Feature Launches with 10,000 Curated Sentences
Clozemaster launched a revamped Fluency Fast Track with 10,000 sentences split into 10 levels of 1,000 each, organized by word frequency. Unlike the Tatoeba-sourced bulk content, Fast Track sentences were vetted by language experts for accuracy. Over 80 topic-specific pages offered curated subsets. The feature expanded across languages including Chinese, German, Hindi, Italian, Japanese, Korean, and Spanish.
AI-Driven Sentence Explanation Feature Officially Announced
Clozemaster formally announced the integration of an AI-driven explanation feature powered by ChatGPT, providing in-depth sentence analysis including grammar breakdowns, vocabulary explanations, and contextual notes. While many users found it valuable, the feature introduced opacity about the accuracy of generated content, as AI explanations sometimes contained factual errors.
Loop Pronunciation Feature Enables Continuous Audio Replay
Clozemaster introduced the Loop feature, allowing learners to continuously replay sentence audio for pronunciation practice. Accessible through game settings, the feature helped users master intonation and rhythm through repeated listening. It was part of a series of 2024 updates improving the audio learning experience.
Clozemaster Expands Welsh Content as Duolingo Retreats
Clozemaster significantly expanded its Welsh language resources with over 10,000 new sentences spanning beginner to advanced levels. The expansion came after Duolingo mothballed its Welsh course in November 2023, positioning Clozemaster as an alternative for Welsh learners. The move reflected the platform's ability to serve minority language communities underserved by larger competitors.
Cloze-Listening Deprecated, Moved to Separate Common Ear Platform
Clozemaster announced that Cloze-Listening would no longer be offered to new users and would receive no further updates, with listening comprehension development shifting to a new separate platform called Common Ear. Existing Cloze-Listening users retained access, but the feature was effectively deprecated. A discount code (COMMONEARFIRST) was offered for Common Ear signups through November 8, 2024.
Forum Users Request Removal of AI Explain Feature
A Clozemaster forum thread titled 'Please consider removing the Explain feature entirely' raised concerns about ChatGPT-generated explanations being unreliable, environmentally wasteful, and potentially misleading for non-expert users. Founder Mike responded that most users benefit from the feature despite shortcomings and that the platform's ChatGPT usage was minimal in environmental terms.
Hands-Free Mode Crashing Continues on Android
Months after initial reports, users continued to report that Hands-Free Mode kept crashing on Android, interrupting learning sessions. The persistence of this bug across multiple app versions highlighted the small team's difficulty maintaining quality across all features and platforms simultaneously.
Pricing Increased to $12.99/Month, $69.99/Year, Up to $199.99 Lifetime
By early 2025, Clozemaster's pricing had risen significantly from its 2022 levels: monthly from $8 to $12.99 (62% increase), yearly from $60 to $69.99 (17% increase), and lifetime from $140 to $159.99-199.99 (14-43% increase depending on platform). iOS pricing remained higher at $79.99/year due to Apple's App Store commission. The increases were implemented without a single announcement, as incremental adjustments over time.
UI V5 Dashboard Redesign Launched
Clozemaster rolled out a major User Interface V5 redesign featuring a simplified dashboard with a green mesh perspective grid background, redesigned statistics layout, new onboarding flow, and mobile widgets for tracking Days Played, Reviews Ready, and Streak. A new 'Teach Me' button was added to the vocabulary text input mode, revealing the cloze answer in light grey when clicked.
Evidence (36 citations)
D1: User Value Erosion
D2: Business Customer Exploitation
D3: Shareholder Extraction
D4: Lock-in & Switching Costs
D5: Twiddling & Algorithmic Opacity
D6: Dark Patterns
D7: Advertising & Monetization Pressure
D8: Competitive Conduct
D9: Labor & Governance
D10: Regulatory & Legal Posture
Scoring Log (4 entries)
Stripped for Phase 2 re-enrichment