Monophonic Synth - Online Play with Oscillator & Envelope
Play a simple monophonic synthesizer with your keyboard. Choose waveform, attack, decay, and filter. For music fun.
UD5 Toolkit
Online CW Practice & Play — Convert text to Morse code audio instantly
Click the paddle or press Space to send. Release to stop.
Fast character speed with longer spacing between characters — ideal for beginners.
Settings are saved automatically in your browser.
Play a simple monophonic synthesizer with your keyboard. Choose waveform, attack, decay, and filter. For music fun.
Pomodoro timer with built‑in lo‑fi music playlist (synthetic). Focus and rest cycles. No copyright music; generated tones.
Play a sweep from 20Hz to 20kHz. Test your speakers and your hearing. Simple and effective. Web Audio API.
Drop an audio file and instantly see its duration in seconds and formatted time. Read metadata without full playback.
Play a selection of local lo‑fi tracks (embedded). Simple UI with play/pause. No copyright issues. Stay focused.
Connect an audio source to an Analyzer Node and display frequency and time‑domain data. Learn Web Audio visualization.
Paste text to see a live letter frequency bar chart. Helps break substitution ciphers. All local analysis.
Load an audio file and see its spectrogram with frequency over time. Adjust resolution and color map. Discover hidden sounds.
Play a collection of retro 8‑bit synth pads and leads using your keyboard. Record sequences and export as WAV. Pure Web Audio API.
Hear a common bird song and choose the correct species from multiple choices. Ear training for birders.
Complete a series of visual pattern puzzles and get a fun estimated score. Purely for entertainment. No data collected.
Mix multiple ambient sounds (rain, fireplace, cafe, forest) at different volumes. Create your perfect background noise. Local loops.
Choose a base color and see its complementary, split‑complementary, triadic, and tetradic harmonies. Copy palettes. Local.
Trigger different vibration patterns on mobile devices. Test if your phone supports haptic feedback. Simple demo.
Mix white noise, pink noise, rain, thunder, wind, and cafe sounds. Individual volume, save presets. Relax or focus. All client‑side.
Register a periodic background sync to fetch fresh data even when the tab is closed. Understand the API and limits.
Process audio faster than real‑time with OfflineAudioContext. Apply filters and export the result. Dev tool.
Apply lowpass, highpass, and reverb to an audio source. See frequency response. Create your own guitar pedal. All local.
Route your microphone input through a chain of virtual effects (distortion, reverb, delay) using Web Audio API.
Interactive piano showing typical vocal ranges from Bass to Soprano. Highlight your range. For choir members.
Experiment with the experimental Prompt API and Summarization API right in your browser. See how the on‑device AI model responds. Requires Chrome with AI features enabled.
Zoom through the electromagnetic spectrum from radio waves to gamma rays. See wavelength, frequency, and applications. Static educational page.
Create experimental glitch noises by toggling virtual circuit bend points. No real electronics harmed. Fun noise toy.
Register a periodic background sync with a minimum interval. See the registration state and tags. Keep content fresh.
Use the Magnetometer API to build a digital compass. See magnetic field strength and heading in real time.
Select color bands to decode a resistor's value, tolerance, and temperature coefficient. Essential for anyone working with electronics hardware.
Pick a method, URL, headers, and body, then send an HTTP request directly from your browser. Debug APIs easily.
Write a pattern and test it against URLs instantly. See which groups match. Learn the modern alternative to regex for routing. Works entirely in the browser.
Register a periodic background sync and see the status. Schedule content updates for your PWA. API demo.
Read the ambient atmospheric pressure in hPa using the Pressure Sensor API (if available). Real‑time graph.