Convert HTML, Articles and Web Pages
into EPUB eBooks

Zin Flow is a cross-platform app for iOS and Mac that converts web articles, HTML pages, and website URLs into clean EPUB e-books.

Getting started is simple:
1. Safari extension (recommended): Browse as usual and save articles to your Library with one tap
2. URL input: Paste any article link directly into the app
3. Share sheet: Share a URL from any app using the share extension

Once saved to your Library, select multiple articles and export them as a single, beautifully formatted EPUB e-book — complete with chapters, cover, and metadata, ready for Kindle, Apple Books, or any e-reader.

📖 Step-by-step guide: Save web pages as e-books with one click →

Yes! Converting HTML content to EPUB is exactly what Zin Flow is built for. When you paste a URL or use the Safari/Chrome extension, Zin Flow automatically extracts the article's HTML content, strips away navigation and ads, and reformats it into a clean, beautifully structured EPUB file. Whether it's a blog post, news article, or tutorial, you get a reader-friendly e-book ready for Kindle, Apple Books, or any EPUB-compatible app.

EPUB is the industry-standard open format for e-books, supported by virtually all e-readers and reading apps. Unlike PDF, EPUB content reflows to fit any screen size, making it perfect for reading on phones, tablets, and e-readers. It also supports rich metadata (title, author, cover, language), table of contents, embedded images, and adjustable font sizes — all while keeping file sizes small. This is why Zin Flow uses EPUB as its export format, giving you maximum compatibility and the best reading experience across all your devices.

Yes! Zin Flow is a fully cross-platform application that supports both iOS and macOS. Whether you're using an iPhone, iPad, or Mac computer, you can enjoy the same features and experience. Your subscriptions and purchases are shared across all your devices, with iCloud sync keeping your Library data automatically consistent across all devices.

Zin Flow works best with article-style content such as blog posts, news articles, and research papers. It is designed to extract the main text content and relevant images while removing navigation and other distractions. For content with very little text, the extraction functionality may not work as expected. With the Library feature, you can also organize multiple related articles into a themed e-book, which is perfect for series articles or tutorials.

The Chrome extension is a major feature in Zin Flow v2.1!

This means Windows users can now seamlessly use Zin Flow's core features!

How it works:
1. Install the Zin Flow extension in Chrome browser on your Windows PC
2. Browse the web in Chrome and click the extension button when you find an article to save
3. The extension syncs the article through the cloud to your Zin Flow app on your phone/iPad
4. Open Zin Flow on your mobile device - the article is already in your Library
5. Convert articles to EPUB e-books anytime, anywhere on your mobile device

What this means for Windows users:
• Cross-platform breakthrough: No Windows app needed - use core features through the browser extension
• Seamless integration: Collect content in your familiar Chrome browser environment
• Mobile reading: Perfect combination of collecting on PC and reading on mobile/tablet
• Just one device needed: Only need to install Zin Flow app on your phone or iPad

Key advantages:
• Solves the limitation of no native Windows app
• Lets Windows users enjoy Zin Flow's powerful content conversion features
• Takes full advantage of PC browsing convenience and mobile reading comfort
• Seamless data connection across all devices through iCloud sync

Use cases:
• Collect materials at office PC, read on phone during commute
• Research topics at home PC, organize into e-books on tablet
• Any content collection and reading scenario requiring cross-device collaboration

The Library feature is the core functionality of Zin Flow, similar to a "Read It Later" service or browser bookmarks. You can save URLs of interest to your Library without immediately converting them to EPUB. Later, you can select multiple articles from your Library and export them as a single EPUB file.

The Library feature is especially useful for:
1. Collecting multiple articles on related topics and exporting them as an organized e-book
2. Saving quality content you discover for reading later
3. Organizing multiple serial articles in the correct order to form a complete work

When exporting, you can customize the chapter structure and order of articles for a personalized reading experience.

📖 Learn how to merge multiple articles into a custom e-book →

Yes! Zin Flow v2.6 introduced the Chapter Editor, giving you full control over your e-book's table of contents.

What you can do:
1. Rename chapters and sections — Directly edit any chapter or section title before exporting
2. Create new chapters — Add empty chapters to better organize your content
3. Delete unwanted sections — Remove sections you don't need
4. Hierarchy protection — Deleting a sub-section preserves the parent chapter, so your planned structure stays intact

On Mac, you can also double-click any title or press the Return key to quickly rename, and use the right-click menu or Delete key for fast management.

📖 Full chapter editing guide →

Yes! Zin Flow v2.7 introduced EPUB cover customization.

Before exporting your EPUB, you can change the cover image to make your eBook truly your own. Here's how:

How to change the cover:
1. Select the articles you want to export
2. Tap the export button and proceed through the chapter organization page
3. On the final export screen, tap the cover image area
4. Choose a new image from your photo library or files
5. The new cover will be applied to your EPUB

If you don't set a custom cover, Zin Flow will automatically scan your articles and select the most suitable image as the cover.

📖 Full cover and export guide →

Yes! Zin Flow v2.7 introduced book metadata editing.

Before exporting your EPUB, you can edit the following book information:

Editable metadata fields:
1. Title — Customize the book title as it appears in your e-reader's library
2. Author — Set the author name for proper attribution
3. Language — Set the language metadata for better reader compatibility
4. Publication Date — Add a publication date to your eBook
5. Publisher — Set the publisher name

How to edit metadata:
1. Select articles and tap export
2. On the final export screen, tap the info/edit icon
3. Modify the fields you want to update
4. The changes will be embedded in the EPUB metadata

📖 Full metadata and export guide →

The article tagging feature helps you better organize and manage your Library content:

How to use:
1. Select any article in your Library and tap the tag button to enter the tag management interface
2. Smart recommendations: The system automatically extracts keywords from the original webpage's meta tags as recommended tags
3. You can choose to use the recommended tags or create custom tags
4. Add multiple tags to a single article for more precise categorization
5. Tags can be reused across different articles once created

Smart recommendation advantages:
• Automation: No need to manually input common tags, saving time
• Accuracy: Based on the original webpage's keyword information, tags are more relevant to the content theme
• Flexibility: Recommended tags are for reference only, you can freely choose or modify them

Overall tag advantages:
• Quickly filter and find articles by topic
• Works with search functionality to improve content retrieval efficiency
• Create personalized content classification systems
• Enhance the organization and manageability of your Library content

The Library search feature makes content finding more convenient:

Supported search methods:
1. Title search: Search by keywords in article titles
2. Description search: Search for keywords in article descriptions
3. Tag search: Find related articles through tag names
4. Source filter: Filter by article source/domain
5. Combined search: Use multiple criteria simultaneously for precise targeting

Search tips:
• Using accurate keywords yields better search results
• Both Chinese and English keywords are supported
• Search results are sorted by relevance
• Combined with tags, you can locate target content faster

For content behind login walls or paywalls, we recommend the following approach:

Recommended: Safari Extension + System Browser (Best Practice)
1. Log in to websites normally in Safari or your preferred system browser
2. Navigate to the article page you want to save
3. Use Zin Flow's Safari extension to save it to your Library with one tap

Safari Extension advantages:
• Seamless experience: Use your familiar system browser with native browsing experience
• Better compatibility: Supports all website login mechanisms and interactive features
• More convenient: No app switching required, one-tap saving
• Auto-login: Leverages your browser's saved login state

iCloud sync allows your Library data, app settings, and saved articles to automatically synchronize across all your iOS and Mac devices. This means articles you save on your iPhone can be immediately accessed on your iPad or Mac without manual transfer.

This feature is enabled by default and requires no additional setup. As long as your devices:
1. Are signed in with the same Apple ID
2. Have iCloud enabled
3. Have iCloud access enabled for Zin Flow

If you don't want to use this feature, you can disable iCloud for Zin Flow in your device's system settings.

HTML (HyperText Markup Language) is the standard language for creating web pages. It's designed for browser display and often includes navigation, ads, and dynamic elements. EPUB, on the other hand, is a dedicated e-book format that packages content into a portable, reflowable file. An EPUB file is essentially a ZIP archive containing HTML, CSS, and images — structured and organized for reading rather than browsing. Zin Flow bridges this gap by taking web HTML and converting it into a clean, structured EPUB with proper chapters, metadata, and formatting optimized for long-form reading.

The free version has the following limitations:
1. Generated e-books will have watermarks
2. Maximum of 10 total trial exports (once used up, exports are disabled)
3. An in-app purchase prompt will appear before each conversion

Upgrading to the Pro version removes all limitations and lets you fully use all features, including unlimited Library capacity, iCloud sync, and Offline Mode. Offline Mode allows paid users to cache article content and images for access anytime without an internet connection.

The Pro version supports one-time purchase as well as monthly/yearly subscriptions. A subscription lets you continue receiving new features and ongoing support.

This is a common issue for users in some regions. When opening the app for the first time after installation, iOS requests network access authorization, which may delay the loading of in-app purchase options.

The solution is simple:
1. Allow network access permission
2. Fully close the app (remove from background tasks)
3. Reopen the app

After restarting the app, the in-app purchase and subscription options should display correctly. This usually only happens after the first installation and won't recur after authorizing network access.

Yes! We recommend using the most stable and reliable methods for different platforms:

For iOS users:
1. Install the official Kindle App on your iPhone/iPad
2. When exporting EPUB in Zin Flow, choose to share with the Kindle App
3. The Kindle App will automatically sync the document to all your Kindle devices

For Mac users:
1. Export the EPUB file to your local storage
2. Upload the document via Amazon's official Send to Kindle website (https://www.amazon.com/sendtokindle)
3. The document will automatically be pushed to all your Kindle devices

Common advantages of these methods:
• More stable and reliable transfer, not limited by email services
• More generous file size limits
• Avoids attachment parsing issues with iCloud Mail Drop functionality
• Avoids various instability issues when sending large file attachments via email in background

Of course, you can still use the email sending feature by configuring your Kindle email address in the app settings, but we strongly recommend using the above methods.

📖 Complete EPUB export and Kindle guide →

Offline mode!

Basic usage still requires an internet connection to fetch web content, but pro users can now use the offline mode:
• When enabled, the system caches article content and images
• Access cached content anytime, even without an internet connection
• Library interface now shows offline cache file sizes for storage management
• Mac version also supports direct viewing of cached articles

Storage Limit Information:
• Offline mode is subject to storage space limits to prevent excessive device storage usage
• You can adjust the maximum offline cache storage capacity in the app's settings page
• When the cache approaches its limit, the system automatically cleans up older or less frequently accessed content
• We recommend regularly reviewing and cleaning up unnecessary offline content to maintain reasonable device storage usage

Note: Initial conversion and saving articles to the Library still requires internet connection, but once offline mode is enabled, you can access this content within the storage limits.

If you see a "Storage Limit Reached" message while saving articles for offline reading, this does not mean your subscription plan has reached any limit.

Offline Mode includes a configurable storage limit to prevent unintentionally caching too many articles and occupying excessive device storage. By default, it's set to 500 MB, but you can change it at any time.

How to resolve it:
Open Settings → Offline Mode → Offline Content Storage Limit, then either:
1. Increase the storage limit according to your available device space
2. Remove offline content you no longer need

This setting only controls local offline storage and does not affect your Pro features or subscription benefits.

Some Kindle devices may display Chinese and other East Asian characters (Chinese confirmed, Japanese and Korean potentially affected) with inconsistent thickness when reading EPUBs if the device doesn't have appropriate built-in fonts. While embedding East Asian fonts into the EPUB would solve this issue, it would significantly increase the file size.

The recommended solution is to install your preferred compatible font in the /fonts directory of your Kindle device. This approach gives you control over which font to use while keeping the EPUB file size manageable.

If you encounter a URL that does not convert properly or has formatting/content issues after conversion, please contact us through our contact page: Contact page. Please provide details about the issue and the URL in question, and our development team will investigate and improve the conversion process. Your feedback helps us continuously enhance Zin Flow's conversion capabilities.