I’m excited to share iNatSpectro by  Japh, a multi-browser extension (Chrome 88+ / Firefox 85+) designed to integrate high-resolution spectrograms directly into iNaturalist observation pages. Built with vanilla JavaScript and the Web Audio API, the tool performs all Digital Signal Processing (DSP) locally in the browser to ensure data privacy and real-time performance. 

Key technical features include support for sample rates up to 384kHz (enabling ultrasonic analysis for bats), configurable FFT window sizes (256-4096 samples), and a perceptually uniform Viridis colormap for accurate signal intensity visualization. The extension uses Vite for its build system and handles CORS headers via declarativeNetRequest to seamlessly process audio across host permissions. We are actively looking for feedback on our DSP parameters—such as window functions and overlap processing—to better support specific taxonomic groups like cetaceans and amphibians. 

Check out our architecture documentation or submit a bug report/feature request to help us refine this open-source tool for the conservation community.