The Q.Z.L Ecosystem

Q.Z.L Corp builds practical tools and software for developers, learners, and researchers. From our flagship URL shortener to vocabulary learning apps and developer utilities, every product is crafted to solve real problems — simply and reliably.

🌐 Web Applications🤖 Android Apps🍎 iOS & macOS (Coming Soon)

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Core Platform

Our flagship service — smart URL shortening with analytics, QR codes, and AI-powered safety.

QZ-L URL Shortener

Live

Free URL Shortener · Link Analytics · QR Code Generator

QZ-L is a free, fast, and feature-rich URL shortener at qz-l.com. Beyond simply shortening links, it offers detailed click analytics, QR code generation for every link, a safety preview system that warns users before visiting suspicious URLs, and an AI-powered link analysis layer that flags malicious or misleading content. The platform supports custom short codes, an open API for developers, and optional subscription plans for power users who need higher limits and advanced analytics.

Problem it solves

Long URLs are unwieldy to share and give recipients no context about the destination. Public shorteners offer no analytics, no safety checks, and no customization. QZ-L fixes all three: every shortened link comes with click tracking, a browser-based safety preview page, and AI analysis — all for free.

Intended users

Content creators, marketers, developers, social media managers, newsletter writers, and anyone who shares links regularly and wants to understand how their audience engages with them.

Use cases

✓Shorten affiliate or campaign links and track click-through rates over time
✓Generate QR codes for print materials, business cards, or event signage
✓Preview any short link safely before clicking — great for security-conscious teams
✓Use the public REST API to automate link creation in CI/CD pipelines or marketing tools
✓Monitor referrer sources, device types, and geographic distribution of link clicks

Visit qz-l.com →

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Developer Tools

Utilities built for developers, DevOps engineers, and technical teams.

QZL Compare

Live

Free Online File, Folder & Text Diff Tool

QZL Compare is a free, browser-based file and folder comparison tool at compare.qz-l.com. It brings the power of desktop diff software like Beyond Compare directly to your browser — with zero installation, zero account creation, and zero file uploads. Every comparison runs entirely locally in your browser, which means your source code, configuration files, and sensitive documents never leave your machine. The tool supports side-by-side and unified diff views, recursive folder comparison, real-time text diff, character-level inline highlights, and export to standard patch files.

Problem it solves

Professional diff tools like Beyond Compare cost money and require installation. Web-based alternatives often upload your files to remote servers, creating serious privacy and security concerns. QZL Compare processes everything locally so your files never leave your device — and it is completely free.

Intended users

Software developers, DevOps engineers, system administrators, technical writers, QA engineers, and students who need to compare code, configuration, or documentation without installing software or exposing sensitive files.

Use cases

✓Compare configuration files across staging and production environments without installing anything
✓Quickly diff two versions of a SQL migration or Dockerfile in the browser
✓Check differences between submitted student code and a reference solution
✓Generate a standard .patch file from text differences for version control workflows
✓Compare entire project folders to detect which files changed between two releases

Visit compare.qz-l.com →

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Learning & Study Tools

Educational tools for vocabulary mastery and theological study — available on Web and Android.

COCA Vocabulary

Live · Web & Android

IELTS & TOEFL Vocabulary Learning · Web & Android

COCA Vocabulary at coca.qz-l.com is a structured vocabulary learning platform built around the Corpus of Contemporary American English (COCA) word frequency list. The app guides learners through the top 16,500 most-used English words with flashcards, quizzes, spaced repetition, and an AI tutor. Progress is tracked with XP points, streaks, and mastery percentages. The same experience is available as an Android app on Google Play under the name COCA Vocabulary IELTS & TOEFL.

Problem it solves

IELTS and TOEFL test-takers often study vocabulary inefficiently, memorizing random word lists without frequency-based prioritization. COCA Vocabulary focuses effort on the words that matter most in academic and professional English, using proven spaced repetition techniques and AI-assisted tutoring.

Intended users

Non-native English speakers preparing for IELTS or TOEFL, university students strengthening academic vocabulary, professionals improving business English, and self-learners who want a structured, data-driven approach to English vocabulary.

Use cases

✓Systematically work through the 16,500 most frequent English words from the COCA corpus
✓Prepare for IELTS Academic or TOEFL iBT vocabulary sections with targeted word practice
✓Use daily streak tracking and XP gamification to build a consistent study habit
✓Ask the AI tutor to explain word usage, nuance, and example sentences in context
✓Track mastery progress from Beginner to Master level across the full word list

Visit coca.qz-l.com →

Westminster Shorter Catechism

Live · Web & Android

Reformed Theology Study Tool · Web & Android

The Westminster Shorter Catechism tool at wsc.qz-l.com provides a clean, accessible interface for studying all 107 questions and answers of the Westminster Shorter Catechism — one of the most significant summary documents in Reformed Christian theology. The tool is designed for daily memorization and review, presenting each Q&A in a readable format optimized for both personal study and group discussion. An Android app version is available on Google Play for offline study on mobile devices.

Problem it solves

The Westminster Shorter Catechism is a dense theological text that benefits enormously from structured, repeated exposure. Most digital formats make it difficult to navigate or study systematically. This tool presents the full catechism in a focused, distraction-free interface designed specifically for memorization and deep engagement.

Intended users

Reformed Christians, theology students, church members in catechism classes, Sunday school teachers, pastors, and anyone studying historic confessional Reformed theology.

Use cases

✓Daily memorization of questions and answers for personal spiritual formation
✓Preparation for church membership classes or confirmation programs
✓Teaching resource for Sunday school teachers and small group leaders
✓Quick reference for all 107 questions and their scriptural answers
✓Offline study via the Android app during commutes or travel

Visit wsc.qz-l.com →

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AI Experiments

Exploratory projects that probe the boundaries of large language model reasoning.

Gemini Guess

Experiment

AI Reasoning Experiment · Powered by Google Gemini

Gemini Guess at gemini-guess.qz-l.com is an interactive experiment that explores how Google Gemini reasons through multi-turn deduction problems. Users think of anything — a historical figure, a philosophical concept, a rare animal, or any object — and Gemini attempts to identify it through a series of targeted questions and logical inferences. The experiment reveals the depth and limits of large language model reasoning in open-ended guessing scenarios.

Problem it solves

Large language models are widely discussed but rarely tested in transparent, interactive ways that non-technical users can engage with directly. Gemini Guess creates a playful yet revealing window into how AI systems build and refine hypotheses across multiple conversational turns.

Intended users

AI enthusiasts, researchers studying LLM behavior, educators demonstrating AI capabilities, product teams evaluating AI reasoning depth, and curious users interested in exploring what modern language models can and cannot do.

Use cases

✓Test how well Gemini identifies obscure historical figures or rare scientific concepts
✓Demonstrate AI reasoning to students or colleagues in an engaging, interactive format
✓Explore the failure modes and confident misfires of multi-turn LLM reasoning
✓Compare performance across different types of subjects: abstract vs. concrete, famous vs. obscure
✓Use as a benchmark exercise when researching AI capabilities for your own projects

Try Gemini Guess →

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Android Mobile Apps

Q.Z.L Corp apps on Google Play — carry your learning tools wherever you go.

Q.Z.L Corp publishes and actively maintains Android applications on Google Play. Our mobile apps bring the same quality and focus of our web tools to your smartphone, with offline support and native mobile experiences. All apps are published under the Q.Z.L Corp developer account.

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COCA Vocabulary IELTS & TOEFL

Learn COCA vocabulary for IELTS & TOEFL with flashcards, quizzes, and an AI tutor. 500+ downloads.

Live on Play Store

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Westminster Shorter Catechism

Study all 107 questions and answers of the Westminster Shorter Catechism on your Android device.

Live on Play Store

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Heidelberg Catechism

Study the Heidelberg Catechism — a foundational document of Reformed Christian theology — on Android.

Live on Play Store

More catechism and theology study apps are currently under development and will be released to Google Play in the coming months.

View all apps on Google Play

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Coming Soon

Q.Z.L Corp is expanding to Apple platforms — iOS and macOS applications are in development.

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iTrans

Fast iPhone Photo & Video Transfer for macOS

iTrans is a native macOS application that enables fast, reliable transfer of photos and videos from iPhone to Mac. Designed as a lightweight, focused alternative to iTunes and Finder for media transfers — purpose-built for speed and simplicity. iTrans will be published on the Apple App Store.

Problem it solves

Transferring large photo and video libraries from iPhone to Mac using Finder or iCloud is slow and unintuitive. iTrans provides a direct, fast path for media transfers with a straightforward interface.

Target users

Mac users who take large volumes of photos and videos on iPhone and want a fast, reliable way to move them to their Mac without using iCloud or iTunes.

Coming to Mac App Store

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iOS Applications

Q.Z.L Corp expanding to the iPhone platform

Following the success of our Android applications, Q.Z.L Corp is developing iOS versions of our most popular apps. Learners and students using iPhone will soon be able to access the same high-quality tools available on Android — fully optimized for iOS and published on the Apple App Store.

◆COCA Vocabulary for iOS
◆Westminster Shorter Catechism for iOS
◆Additional theology and study apps

Coming to App Store

About Q.Z.L Corp

Q.Z.L Corp is an independent software company that builds practical tools and applications for developers, learners, and researchers. Our philosophy is simple: identify a real problem, build the simplest tool that solves it well, and make it freely available to the community.

We develop and maintain products across four platforms: Web, Android, iOS, and macOS. Each product is actively maintained and improved based on user feedback. We share our building journey with the community through our blog, where we write about product decisions, technical challenges, and lessons learned along the way.

Our flagship product — the QZ-L URL Shortener — remains the heart of the ecosystem. All other tools reflect the same commitment to quality, privacy, and usefulness that defines the Q.Z.L approach to software.

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Web Applications

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Android Apps

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Soon

Apple Platforms

🛠️

Free

Open API

Start with our flagship tool

The QZ-L URL Shortener is free to use. Shorten your first link, generate a QR code, and explore your analytics — no account required.

Shorten a Link for Free Learn More About Us