Google open-sources Walt, a tool that measures lag for touch and voice commands

Google today talked for the first time about Walt, a piece of software that people can use to figure out how long it takes for a device to respond to touch or voice input. Google has been using Walt to do performance tests on Android devices and Chromebooks, and now the software is available under an open source Apache license on GitHub.

To use Walt, you’ll need some hardware like a microcontroller, an accelerometer board, and a laser, but the entire kit shouldn’t cost more than $50, Google software engineer Mark Koudritsky wrote in a blog post. Here’s how it works, according to Koudritsky:

An important innovation in WALT (a descendant of QuickStep) is that it synchronizes an external hardware clock with the Android device or Chromebook to within a millisecond. This allows it to measure input and output latencies separately as opposed to measuring a round-trip latency.

Like other big web companies, Google regularly open-sources software, such as its TensorFlow machine learning software library.

Systems for optimizing hardware are not very common, though. Because it’s out in the open now, it could help other companies intent on measuring and ultimately improving device responsiveness, like Apple.