File Lens

File Lens is the fast, private file comparison tool for developers - compare Text, JSON, CSV, and XML files right on your phone. See every change instantly, with desktop-grade clarity built for a mobile screen.

YOUR FILES NEVER LEAVE YOUR DEVICE
File Lens compares your files entirely on-device. No account, no cloud sync, no AI processing, and no backend server ever sees your content - your code, configs, and data stay private, even without an internet connection. The app is ad-supported to stay free; ads are the only network activity in the app, and they never have access to your files.

SUPPORTED FORMATS
• Plain text - line-by-line comparison with a proper comparison algorithm
• JSON - structural comparison, not just raw text, with JSON-path locations for every change
• CSV - row and column comparison, with optional key-column matching
• XML - structural comparison of elements and attributes, with XPath-style locations

POWERFUL COMPARISON ENGINE
• Choose between Myers or Patience comparison algorithms
• Clearly marked added, removed, modified, and unchanged lines
• Ignore-whitespace and ignore-line-ending options
• JSON pretty-printing with optional key-order normalization
• CSV delimiter auto-detection and header handling
• Malformed files never crash the app - they gracefully fall back to a plain text comparison

BUILT FOR PHONES
• Side-by-side view on tablets and wide screens, stacked view on phones
• Line numbers and horizontal scrolling for long lines
• Synchronized scrolling between File A and File B
• Collapse unchanged sections to focus on what matters
• Jump straight to the next or previous change

SEARCH & FILTER
• Search across both files at once, with case-sensitive and regex modes
• Jump between matches with next/previous navigation
• Filter the view to show everything, changes only, or just added, removed, or modified lines

EXPORT & SHARE
• Export the full comparison as TXT or a styled HTML report
• Export a quick summary of what changed
• Share results instantly using your phone's native share sheet

RECENT COMPARISONS
File Lens remembers your recent comparisons - file names, format, and summary stats - so you can pick up where you left off. History stays on your device and can be cleared anytime; file contents are never stored.

WHO IT'S FOR
Developers, QA engineers, and anyone who needs to quickly compare config files, API responses, log snippets, spreadsheets, or markup - without opening a laptop.

File Lens is a lightweight, privacy-first alternative to desktop file comparison tools, designed from the ground up for mobile. Download it now and see what changed in seconds.