Full Guide: From Song Upload to Karaoke Video
This guide walks you through the entire Karapella workflow - from uploading a song and selecting a stem, through previewing and processing, to generating a synced karaoke video.
Selecting Your Stem with the DJ Knob
On the home page, you'll see the DJ Knob - a circular selector with dots around it representing 11 available stems: Karaoke, Vocals, BG Vocals, Drums, Bass, Acoustic Guitar, Electric Guitar, Piano, Synth, Strings, and Wind. Click a dot to select the stem you want to isolate. For karaoke video creation, select the "Karaoke" stem.
Uploading Your Song
Upload your audio file by dragging and dropping it onto the center of the DJ Knob, or click the center to browse your files. Once uploaded, the filename appears with a ✕ button to remove it if needed. If you selected the Vocals stem, you'll also see a Dereverb toggle. There's also a "Skip preview" toggle to process the full file directly (this costs balance).
Preview Processing
Click "Start Preview" to begin. A circular progress ring appears with a percentage indicator. Status messages cycle through: "Preparing your track...", "Separating stems...", "Analyzing audio...", "Creating your preview sample...", "Almost ready...", and finally "Done!"
Reviewing Your Preview
After processing, you'll see the DualPlayerMixer - an interactive waveform player where you can listen to and compare the separated tracks. An amber notice reminds you: "Preview includes a short Karapella jingle. Process full file for clean audio." For karaoke stems, you'll also see the KaraokeScreen - a 16:9 preview area with a "Generate Lyrics" button in the center.
Processing the Full File
When you're satisfied with the preview quality, click "Process Full File." A confirmation modal shows the balance that will be deducted (measured in seconds). Confirm to begin full processing. The same circular progress ring appears with status messages: "Separating stems...", "Processing full track...", "Separating audio layers...", "Finalizing your files...", "Done!"
Full Results
Once complete, the DualPlayerMixer updates with the full-length tracks and the "Download All" button becomes active. For non-karaoke stems, you can download your files immediately. For karaoke stems, you can now generate lyrics and create a video.
Generating Lyrics (Karaoke Stem Only)
With your full karaoke tracks ready, click "Generate Lyrics" on the karaoke screen. Within seconds, Karapella AI analyzes the audio and produces synced lyrics that appear overlaid on the video preview. Press play to see the synchronized lyrics in action.
Editing Lyrics
Click any lyric line on the karaoke screen, then click "Edit Line" to open an inline text editor where you can fix spelling or wording. Below the karaoke screen, the Timeline panel shows a waveform with colored regions for each lyric segment. Use the toolbar buttons - Split, Merge, Del, Undo, Redo - to adjust timing. The Delay slider shifts all lyrics globally (e.g., 0.5s earlier so singers can anticipate). Right-click any region for a context menu with Split at Cursor, Merge with Next, Delete Line, and Add Region Here.
Generating Your Karaoke Video
Once lyrics are finalized, click "Generate Video." A consent modal appears with a checklist (lyrics look good, background is right, maximum 3 attempts). Before generating, you can customize the background using the thumbnail strip at the bottom of the karaoke screen (select a color, image, or upload your own with the "+" button). Use the Subtitle Style drawer to adjust font, size, colors, outline, glow, pill, shadow, position, and margin. After confirming, a progress bar tracks generation. When complete, a green "Video ready!" card appears with a Download button.
Downloading Your Files
All your completed files - separated tracks and karaoke video - are available via the "Download All" button on the results page, or from the My Files section accessible via the navigation bar.