Everything happens inside your browser, on your own device. Your score and audio are never uploaded.
Your files stay with you
When you add a PDF or an audio file, your browser reads it into this tab’s memory. Nothing is sent to a server, and closing the tab clears it. The only things fetched from the internet are the PDF tools and the fonts the page uses, including any font you pick for the credits.
Your score
PDF.js, from Mozilla, draws each page. Reordering, leaving pages out, rotating, repeating, resizing and watermarks are kept as a list of instructions on top of your original, so your original PDF is never changed. Export PDF builds a new file from that list and keeps the pages as sharp vector artwork.
Your audio
Your browser decodes the audio and the waveform is measured on your device. Trim, fades, normalize and gain are applied the same way when you listen and when you export. WAV files are written directly, and M4A files are encoded by your browser’s built-in AAC encoder.
Page turns
Each turn is drawn with WebGL, the graphics your browser uses for 3D. The page bends, casts a shadow and flips on your graphics hardware, and the timing comes entirely from the turns you set.
Your video
Every frame is rendered and encoded by your browser, with audio encoded as AAC. A small piece of code in the page packs them into an MP4 file. If your browser can’t encode fast enough, it records the preview in real time instead.
Saved settings
Your settings are remembered in this browser only. Import and Export save them to a small text file that you keep.