Privacy Policy for DevUtilities

Last Updated: October 2025

Overview

DevUtilities ("the App") is a native macOS developer utility application created by Hengfei Yang. This privacy policy explains how the App handles your information.

Information Collection and Use

Anonymous Usage Analytics

DevUtilities collects anonymous usage analytics to improve the app and understand which features are most valuable to users.

What We Collect

We collect anonymous usage events only:

• App Start Events: When you launch the app
• Feature Usage: Which tools you use (e.g., JSON Formatter, Base64, JWT)
• Navigation Patterns: How you navigate between different tools
• Session Information: App version, anonymous session ID

What We DO NOT Collect

We do not collect any personal or sensitive information:

• ❌ No personal information (name, email, phone number)
• ❌ No device identifiers (UDID, serial numbers, MAC address)
• ❌ No IP addresses or location data
• ❌ No file contents or data you process in the tools
• ❌ No API keys or credentials
• ❌ No chat messages or translation content
• ❌ No advertising tracking or third-party analytics services

Anonymous Identifiers

• User ID: A randomly generated UUID stored locally on your device. This is NOT linked to your Apple ID, email, or any personal information. It helps us understand unique users and retention.
• Session ID: A temporary UUID generated each time you launch the app. This helps us understand session duration and feature usage patterns within a single session.

Both identifiers are completely anonymous and cannot be used to identify you personally.

Local Data Storage

The App stores the following information locally on your device only:

1. User Preferences: Your customization settings (enabled/disabled tools, tool order)
2. API Configuration: AI feature API keys and endpoints (stored in macOS UserDefaults)
3. Chat History: AI Chat conversation history (stored locally in app container)
4. Recent History: Recent conversions, requests, or inputs for convenience

All this data:

• Remains on your device
• Is never transmitted to our servers
• Can be deleted by removing the app
• Is protected by macOS sandboxing

Network Usage

DevUtilities requires network access for specific features only:

1. AI Features (AI Chat, AI Translate)

• Purpose: Connect to user-configured AI API endpoints
• User Control: Users must provide their own API keys
• Data Sent: Chat messages and translation text to user's chosen API provider
• We Do Not: Store, log, or have access to API keys or conversation content
• Third Party: Your data is subject to your chosen AI provider's privacy policy

2. IP Query Tool

• Purpose: Lookup IP address geolocation information
• Services Used: ipinfo.io and ip.sb public APIs
• Data Sent: IP addresses you choose to query
• We Do Not: Log or store queried IP addresses

3. HTTP Request Tool

• Purpose: Developer testing tool for making HTTP requests
• Data Sent: Only to endpoints you explicitly specify
• We Do Not: Log, monitor, or intercept your requests

4. Usage Analytics

• Purpose: Understand feature usage and improve the app
• Service Used: Our analytics server (api.devutilities.feiliwu.com)
• Data Sent: Anonymous events (see "Anonymous Usage Analytics" section above)
• Data Format: GET requests with query parameters (version, module, submodule, anonymous user_id, session_id)
• Opt-Out: You can disable analytics in app preferences (coming soon)

5. Update Checking

• Purpose: Check for new app versions on GitHub
• Service Used: GitHub Releases API
• Data Sent: Standard HTTP request (no personal information)

Offline Functionality

The following tools work completely offline without any network access:

• Timestamp Converter
• Unit Converter
• JSON Formatter
• Base64 Encode/Decode
• Hex String Converter
• Regex Test
• UUID Generator
• URL Tools
• QR Code Generator/Scanner
• SQL Formatter
• HTML Formatter
• JWT Encoder/Decoder
• Parquet Viewer
• Crypto Tools

Cryptographic Features

The App provides cryptographic tools (hash functions, encryption/decryption) for developer use:

• All cryptographic operations are performed locally on your device
• The App uses standard Apple frameworks (CryptoKit, Security)
• No encryption keys are transmitted or stored by us
• Users are responsible for securing their own keys

Third-Party Services

Analytics Server

DevUtilities sends anonymous usage events to our own analytics server to understand feature usage. No third-party analytics services (Google Analytics, Mixpanel, etc.) are used. We control the data and do not share it with any third parties.

No Advertising or Tracking

• No advertising networks
• No cross-site tracking
• No data brokers
• No data sales to third parties

AI Features

When you use AI Chat or AI Translate with your own API keys, you are directly connecting to third-party AI services (OpenAI, DeepSeek, or custom providers). Your usage is subject to those providers' privacy policies and terms of service.

Children's Privacy

DevUtilities is not directed to children under 13. We do not knowingly collect information from children. If you believe a child has used the App, please contact us.

Data Security

• All user data is stored locally using macOS sandboxing
• API keys are stored in UserDefaults on your device only
• Anonymous analytics transmitted over HTTPS with TLS encryption
• Events queued locally if network unavailable, sent later
• Standard macOS security protections apply
• We do not store, log, or have access to your processed data (JSON, text, files, etc.)

Your Rights

You have complete control over your data:

• Access: All personal data is stored locally and accessible via standard macOS file locations
• Deletion: Remove the App to delete all local data and stop sending analytics events
• Portability: Export any data using standard macOS tools
• Opt-Out: Analytics can be disabled in app preferences (feature in development)
• Anonymous Data: Since analytics are anonymous and not linked to you personally, we cannot retrieve or delete specific analytics data upon request

Changes to This Privacy Policy

We may update this privacy policy from time to time. Updates will be posted on this page with a new "Last Updated" date. Continued use of the App after changes constitutes acceptance of the updated policy.

Contact Information

If you have questions or concerns about this privacy policy:

• Issues: Report an issue
• GitHub: https://github.com/hengfeiyang/devutilities
• Website: https://hengfeiyang.github.io/devutilities

Analytics Data Details

Example Analytics Event

GET https://api.devutilities.feiliwu.com/event?
    user_id=550e8400-e29b-41d4-a716-446655440000&
    session_id=6ba7b810-9dad-11d1-80b4-00c04fd430c8&
    version=2.5.0&
    module=json_formatter&
    submodule=format

What this tells us:

• An anonymous user (identified by random UUID) used the JSON Formatter feature
• They're running version 2.5.0 of the app
• This was during a specific app session

What this does NOT tell us:

• Who you are or any identifying information
• What data you formatted (your actual JSON content)
• Your location or IP address
• Any other apps you use or personal information

Data Retention

• Local Queue: Anonymous events stored locally for up to 7 days before automatic cleanup
• Server Storage: Anonymous usage statistics retained for analytics and product improvement
• No Personal Data: Since no personal information is collected, there's nothing personally identifiable to delete

Compliance

This privacy policy complies with:

• Apple App Store Review Guidelines
• General Data Protection Regulation (GDPR) principles
• California Consumer Privacy Act (CCPA) principles
• macOS App Sandbox requirements

Developer Information

• Developer: Hengfei Yang
• App Name: DevUtilities
• Version: 2.6.0
• Bundle ID: com.hengfeiyang.devutilities

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