Guides ·
Troubleshooting the Audio Visualizer: Browser, AAC, and Large Exports
Most problems with the visualizer come from one of three places: the browser, the encoding library that loads when you first render, or the size of the export. This page goes through the messages you might see and what to do about each one.
Start with the browser check
The pill at the top right of the workspace shows a short check when the page loads:
- Encoder ready / Encoder unavailable: whether the browser supports WebCodecs and the MP4 library loaded. Both are needed for export. Hover over the pill to see which part failed.
- Saves straight to disk / Saves in memory: whether the browser can stream large exports straight to a file. With “Saves in memory”, exports still work but are held in memory until they finish.
If it shows “Encoder ready”, export will work. If not, preview still works, so you can tune the look while you fix the problem.
WebCodecs not available
What it means: The browser does not provide the WebCodecs video encoder, so the export buttons are disabled. The status line says the browser does not support WebCodecs.
Fix:
- Use a current version of Chrome or Microsoft Edge on desktop. These are the browsers the tool is built and tested on.
- Update the browser if it is old. WebCodecs is a relatively recent API.
- If you use a Chromium-based browser with privacy hardening, check whether it disables media APIs, and try regular Chrome to compare.
Mobile browsers are not a good fit even when they support WebCodecs: long exports need a lot of memory, and phones suspend background tabs aggressively.
The encoder failed to load
What it means: The MP4 library is part of the site and loads from the same address as the page. If it cannot load, the check shows “Encoder unavailable” and the status line under the preview shows the error.
Common causes and fixes:
- The connection dropped while the page was loading. Reconnect and reload.
- An aggressive script blocker blocked part of the page. Allow the site, then reload.
Preview does not need the library, so it keeps working while export is unavailable.
Analysis failed
What it means: When you select a track, the page decodes the whole file and analyzes it. If decoding fails, the status line shows “Analysis failed” with the browser’s error message.
Fix:
- Check that the file plays in Chrome on its own (drag it into an empty tab).
- Convert unusual formats or codecs to WAV, MP3, or M4A (AAC) in an audio editor.
- Re-export the file if it may be truncated or damaged.
Files with an audio-type extension but an unsupported codec inside will fail here even though they are accepted into the queue. Standard MP3 and WAV downloads from music services such as Suno decode normally in Chrome.
The export has no audio, or fails at the start
The MP4’s audio is encoded as AAC. The WebCodecs specification does not require browsers to support AAC encoding, and some builds do not. The page checks for native AAC support before each export, and if it is missing, loads a fallback AAC encoder that ships with the site and uses that instead.
If the fallback cannot load (same causes as the encoder failure above), the export can stop with an error. Reload and try again. Using a standard Chrome build from Google usually avoids the issue, because it includes native AAC encoding.
Buttons do nothing during analysis or export
While a track is being analyzed or an export is running, the page locks the queue: you cannot select a different track, reorder, play, or seek. This prevents the analysis data from changing under the encoder. Wait for the status line to finish, or stop the export.
To stop an export: click the export button again. During export it becomes a stop button. An in-memory export saves nothing when stopped. If the export was streaming to a file you chose, check that location afterward and delete any incomplete file.
Long playlist exports
When you export all tracks into one file, the page estimates the final size. If it is over about 80 MB, Chrome shows a save dialog before encoding starts, and the video streams to that file while encoding.
Problems you may hit:
- You cancel the save dialog. The status line shows that saving was canceled and nothing is exported. Click export again and choose a location.
- The save dialog fails to open. The page falls back to building the file in memory. That works for moderate lengths but can run out of memory on very long playlists.
- The browser tab crashes or the export stalls on a very long playlist. Split the queue into two or three parts and export them separately; the bars restart at every song boundary, so the joins in your editor are invisible.
- Progress stops when you switch tabs. Some browsers slow down background tabs. Keep the tab visible.
A track whose duration still shows “—” in the queue has not loaded its metadata yet. If any track in a multi-track export has an unknown duration, the page cannot estimate the size and asks for a save location to be safe.
Bars look wrong
| Symptom | Likely cause | Fix |
|---|---|---|
| Right side of the bars barely moves | Music has little high-frequency energy | Raise High-frequency boost |
| Most bars stay at the top | Track is loud for the current settings | Lower Sensitivity |
| Bars never drop to zero | Floor is too low for this track | Raise Floor |
| Bars twitch nervously | Smoothing too low, or High-frequency boost and Sensitivity amplifying hi-hats and noise | Raise Smoothing, then lower High-frequency boost a little |
| Bars feel sluggish | Smoothing too high | Lower Smoothing |
| Leftmost bars move in identical pairs | FFT resolution limit in the deep bass | Normal; fewer bars reduces it |
Problems in the video editor
- Black background still visible: set the visualizer clip’s blend or composite mode to Screen or Add, and make sure it sits on a track above your footage.
- Bars stutter: export at the same frame rate as your editing project.
- Bars look blurry: export at a larger size instead of scaling up in the editor.
The overlay guides for DaVinci Resolve, Premiere Pro, and CapCut cover each editor step by step.