Simon Willison’s Weblog

Timing and Synchronization in JavaScript. Comprehensive overview of how browsers (Opera in particular) load scripts and queue events, with suggestions for best practices.

Posted 30th April 2007 at 2:24 pm

Recent articles

GPT-5.2 - 11th December 2025
Useful patterns for building HTML tools - 10th December 2025
Under the hood of Canada Spends with Brendan Samek - 9th December 2025

browsers 93 javascript 727 opera 31 timing 1

Monthly briefing

Sponsor me for $10/month and get a curated email digest of the month's most important LLM developments.

Pay me to send you less!

Sponsor & subscribe