Fully private by design
No data is ever uploaded to any server or shared with any third party. All processing happens locally in your browser — ideal for source code, client files, credentials, or sensitive documents.
100% Private — Zero Server Uploads
Browser tools that never send your data to a server or any third party
LightDarkTools is built for people who need free, secure online tools without trusting a third-party backend with their files. Whether it's source code, confidential documents, archives, app screenshots, or personal QR data — every tool runs entirely on your device, inside your browser. No uploads, no accounts, no data sharing. Ever.
Zero server uploads
No data shared with third parties
Runs 100% locally in your browser
No account or login required
Universal Diff Tool
Compare text, code and readable documents. Supports all data storage formats. Secure and private. No data is ever uploaded to any server. All comparisons happen locally within your browser.
Secure QR Code Generator
Create premium, custom QR codes locally. Supports URLs, Wi-Fi, Contacts (vCard), and more. Customize colors, shapes, and logos. 100% client-side. No data is sent to servers, no login needed.
App & Play Store Screenshot Maker
Create Play Store and App Store screenshot listings. Upload up to 8 (Android) or 10 (iOS) screenshots, add captions, choose gradient backgrounds, and download them all as a ZIP. 100% client-side - no login required, nothing is ever uploaded to any server.
Make PDF Mobile Friendly
Upload a PDF and rebuild it into a more mobile-friendly reading PDF. Text is reflowed into readable blocks and mapped images are carried into the output for easier reading on smaller screens. 100% client-side - your PDF never leaves your browser.
New
ZIP & TAR.GZ Compressor and Extractor
Securely compress or extract ZIP and TAR.GZ files directly in your browser. Fast, 100% private processing with no file uploads. Supports folders and multiple files.
Play Store
Offline Password Manager
An Android app for storing and managing passwords directly on your device, with an offline-first approach focused on privacy and simple access.
New
Secure PDF Password Remover
Unlock encrypted PDFs locally in your browser. Enter the password once and download a decrypted copy. 100% private, no uploads.
🚧 Development in Progress
More tools are currently being built. Check back soon.
Why people use this site
Built for real tasks people search for
These tools are designed around jobs users commonly need help with: comparing two JSON files online, creating a Wi-Fi QR code, compressing a folder without uploading it, turning a wide PDF into something readable on a phone, or preparing app store screenshots quickly.
Focused workflows
Instead of overwhelming dashboards, each page is tuned for one clear job so users can arrive from search, finish the task, and move on quickly.
Discover related tools easily
Tool pages and guides link to adjacent workflows, making it easy to move between tasks like QR creation, file comparison, and archive handling without starting from scratch.
Guides
Step-by-step guides for common tasks
Each guide walks through a real task step by step and links directly to the tool that handles it. Useful when you have a specific question and want a clear answer fast.
Diff
How to compare two JSON files online without uploading them
Practical ways to review API responses, config files, and structured data with a browser-based diff workflow.
QRHow to create a Wi-Fi QR code that guests can scan instantly
Set up a QR code for a home, office, or event network without sharing the password manually.
PDFHow to make a PDF easier to read on a phone
Use a reflow-style workflow to turn cramped pages into a more comfortable mobile reading format.
PDF SecurityHow to remove a password from a PDF when you already know it
Create a password-free copy locally in your browser for documents you are authorized to access.
App MarketingApp store screenshot tips for Android and iPhone listings
Improve screenshot clarity, sequencing, captions, and exports before you upload store assets.
ArchiveHow to compress and extract ZIP or TAR.GZ files online
Pack files locally into archives or extract zip and tarballs entirely in your browser without uploads.
FAQ
Common questions about LightDarkTools
Is my data safe? Are files ever uploaded to a server?
Completely safe. Every tool on LightDarkTools runs 100% in your browser — no data is ever sent to any server, stored remotely, or shared with any third party. Your files, text, and QR data stay entirely on your device.
Which tool should I use for a specific task?
The Universal Diff Tool handles text, code, JSON, and document comparisons. The QR page covers URL, Wi-Fi, contact, email, and SMS codes. Other pages focus on ZIP and TAR.GZ workflows, making PDFs readable on phones, and creating app listing screenshots.
Can I find related tools from each page?
Yes. Tool pages include related guides and links so you can move between archive, QR, PDF, screenshot, and comparison workflows without going back to the homepage.