What causes a gap when looping an AudioBufferSourceNode?

AudioBufferSourceNode is single-use and its default loop spans the whole buffer including decoder padding, so restarting or trailing silence creates an audible gap.

How do I catch this when it only happens for some players?

Capture it automatically from the player's device with the full stack trace, the device and OS, the build, and a breadcrumb trail of what they did. That turns a vague complaint into a specific, reproducible issue you can fix without owning the hardware it happens on.

How to Fix a Gap When Looping with AudioBufferSourceNode in Web Audio

Quick answer: Set node.loop with precise loopStart and loopEnd to skip padding, and create a fresh source node for each playback since a stopped node can't be reused.

Your looping track has a hiccup at the seam, or it just won't play a second time. Web Audio source nodes are one-shot and loop over the entire decoded buffer by default.

How to fix it

1. Trim the loop region

Set source.loopStart and source.loopEnd to the exact musical region in seconds, excluding MP3/AAC decoder padding that causes the gap.

2. Create a new node each time

An AudioBufferSourceNode can be started once. To replay, build a new node from the same AudioBuffer rather than reusing the old one.

3. Prefer WAV for tight loops

Encoders like MP3 add priming samples that break seamless loops. Decode a WAV/Ogg source for sample-accurate loop boundaries.

Catching the ones you can't reproduce

The hardest version of this to fix is the one you can't reproduce — it only happens on a player's hardware, OS, driver, or save state, under conditions that simply aren't present on your machine. A report that says “it crashed” or “it froze” gives you nothing to act on, so the bug survives release after release while quietly costing you players.

Automatic error capture closes that gap. Each failure arrives with its full stack trace, the device and OS, the build number, and a breadcrumb trail of what the player did right before it broke, so even a failure you have never seen becomes a specific, reproducible issue. Fold identical failures into one signature ranked by how many players each hits, and your worklist sorts itself worst-first instead of arriving as a stream of vague complaints.

This is where a tool like Bugnet earns its place. Its SDK captures every HTML5 error automatically with the full stack trace plus device, OS, memory, build, and game-state context, folds duplicates into one grouped issue with an occurrence count, and ties each to the build it first appeared on — so you fix the problem that hurts the most players first and confirm it is gone when its signature disappears from the next release.

Reproduce it once with full context and the fix writes itself. The hunt is the expensive part.