iNatSpectro by Japh

iNatSpectro v3.5.0

Visualise Nature's Sounds on iNaturalist

This extension adds a dynamic spectrogram visualisation beneath audio recordings on iNaturalist.org observation pages. Whether you're identifying frog calls, bat echolocation, bird songs, or other natural sounds, this tool lets you see what you're hearing.

🎧 Why use it?
Many wildlife sounds are easier to interpret with visual context—especially in noisy environments or when calls are hard to distinguish by ear. This spectrogram helps researchers, identifiers, and curious naturalists analyse recordings at a glance.

🔬 How it works
The extension uses the Web Audio API to render a real-time spectrogram whenever you play an audio file on an iNaturalist observation. It loads automatically and blends seamlessly with the existing page.

🔍 Features in v3.5.0:
• Security & reliability - Hardened message handling, secure fetch timeouts, and extension-only storage for your settings
• CRITICAL FIX: Audio playback restored - Fixed CORS issue that prevented audio from being audible (v3.4.0)
• Enhanced CORS handling - Improved timing ensures audio loads correctly with Web Audio API access
• Automatic error recovery - Smart fallback mechanisms prevent audio failures
• Automatic spectrogram loading - Spectrograms appear instantly when you visit observation pages
• Enhanced zoom functionality - Smooth, error-free zooming from 100% to 2000% with progressive high-resolution rendering
• Advanced caching system - Intelligent memory management with LRU eviction for better performance
• Automatic taxon-based profile selection (bat, bird, frog, insect, cetacean, general)
• Full spectrum analysis - Including ultrasonic frequencies up to 384 kHz for bat research
• Configurable high-resolution rendering (50-800 pixels/second) with automatic performance optimization
• Multiple frequency scales - Toggle between logarithmic, linear, and mel (perceptual) scales
• Interactive controls - 7 adjustable parameters for brightness, frequency range, smoothing, and resolution
• Professional viewport caching - Progressive rendering delivers crisp detail during zoom operations
• Robust error handling - Comprehensive fallbacks ensure reliable operation across all browsers
• No tracking, lightweight — Built specifically for the iNaturalist community

🧬 Perfect for:
• Citizen scientists and professional biologists
• Bat, frog, bird, insect, and whale call analysis
• Educators and ecoacoustics enthusiasts
• Research-grade bioacoustic analysis up to 384kHz
• Anyone who wants to bring audio observations to life visually

🚀 What's New in v3.5.0:
• Security hardening - Sender verification for extension messaging, scoped internal events, and URL re-validation before loading audio
• Performance improvements - Safer handling of long recordings, faster rendering via optimized data transfer and batched canvas drawing
• Reliability - Finite fetch timeouts, session limits, and sanitized error reporting for a more stable experience
• Settings storage - Your preferences now persist securely in extension storage only (no page storage)

iNatSpectro integrates seamlessly into iNaturalist, respects your privacy, and helps you get more from every audio observation—visually. All audio processing happens locally in your browser using the Web Audio API, with no data collection or transmission.

Version 3.5.0 delivers security and performance improvements under the hood, with hardened messaging, safer audio loading, and faster spectrogram rendering—especially on long recordings. Perfect for both casual nature enthusiasts and professional researchers.