# Speaker Tester Check your left and right speakers (or headphones) with a clean test tone — one channel at a time or both. Tones are generated on the fly with no audio files. Runs in your browser. ### How it works A Web Audio `OscillatorNode` generates a pure sine tone, and a `StereoPannerNode` sends it fully to the left channel, the right, or both. If you hear the tone from the correct side, that speaker works. Everything is synthesised live in your browser — no downloads, no files, nothing sent anywhere. --- *Source: [ocxly.com/speaker-tester.html](https://ocxly.com/speaker-tester.html) — OCXLY, free 100% client-side privacy-first tools. Free online speaker tester. Check your left and right speakers or headphones with a clean test tone, one channel at a time or both. Tones are generated live, entirely in your browser.*