Willison ships a millisecond-to-time converter to stop doing the math himself

Simon Willison published a small utility that converts milliseconds into seconds and minutes, built because LLM tooling routinely emits prompt durations in raw ms and the mental conversion was getting tedious. It’s a single-purpose web tool aimed squarely at developers who stare at LLM telemetry all day.

The post is brief and pragmatic — no framework, no abstraction, just a concrete fix for a recurring papercut in the LLM developer workflow. It sits alongside Willison’s other recent tinkering (DeepSeek V4 evaluations, in-browser PDF text extraction, and GPT-5.5 pelican drawings) as part of his ongoing pattern of shipping tiny tools that scratch immediate itches.