Dev Tools for Mobile Developers
Mobile developers work at the intersection of tight resource constraints and diverse screen sizes. App icons at every required resolution, image assets optimized for bandwidth, JWT tokens from auth APIs, push notification payloads as JSON, and regex patterns for client-side validation — all are daily concerns. This collection covers the tools that eliminate the tedious parts of mobile development: asset generation, data inspection, and format conversion, all accessible from a browser without additional tooling.
Generate all standard iOS and Android app icon sizes from a single source image.
Resize images to exact dimensions with optional aspect ratio lock, entirely in your browser.
Compress images by adjusting JPEG quality to reduce file size without leaving your browser.
Resize multiple images to a target width while preserving aspect ratio. Preview and download each result.
Compress multiple images at once with a quality slider. See savings per file and download individually or all at once.
Convert JPEG images to WebP format with a quality slider — runs entirely in your browser.
Convert PNG images to JPEG with a quality slider and see the before/after file size.
Convert an image file to a Base64 data URI string.
Convert a Base64 data URI string back to a viewable image.
Pretty-print and format JSON with proper indentation.
Check if your JSON is valid and find syntax errors.
Decode and inspect JSON Web Token header and payload.
Break down a URL into its individual components using the browser URL API.
Decode Base64-encoded strings back to readable text.
Encode text or binary data to Base64 format.
Generate random UUIDs (v4) for use as unique identifiers.
Test regular expressions against text with real-time match highlighting.
Convert Unix timestamps to human-readable dates and vice versa.
Generate a scannable QR code from any text or URL and download as PNG.
Convert colors between HEX, RGB, and HSL formats with a live preview swatch.
FAQ
- How do I generate all required app icon sizes at once?
- Use the App Icon Generator — upload a single high-resolution image (1024×1024 minimum) and it generates all required icon sizes for iOS App Store, Android adaptive icons, and web app manifests in a single download.
- How do I inspect a JWT from a mobile auth SDK?
- Copy the JWT from your debugger or log output and paste it into the JWT Decoder. It shows the header (algorithm), payload (claims like user ID, roles, and expiry time), and verifies the structure. This is useful for debugging auth flows without making extra network requests.
- How do I optimize images for a React Native or Flutter app?
- Use the Bulk Image Compressor to reduce file sizes without visible quality loss. The Image Resizer generates assets at exactly the @1x, @2x, @3x (iOS) or mdpi/hdpi/xhdpi (Android) sizes you need. Converting PNG to WebP with the converter can reduce image asset sizes by 25–35%.