Tag: warnings

Firefox got real slow

One day Firefox just came to a crawl when running web pages with JavaScript. Then I found out what was causing it and how to fix it. Here’s how.

I was using the Firefox 3.6.16 web browser and it got really slow.  Unbearably so.

When I went to look at the console, it was filled with all kinds detailed of JavaScript warnings, the kind one might expect out of JSLint.  It was spending so much time checking the JavaScript code that it was barely spending time executing it.

The “culprit” was the Web Developer add-on.

Normally, the Disable / Disable JavaScript / Strict Warnings menu item is checked.  Unchecking it gives some fantastic diagnostic messages when writing code.  Forget to re-check it and regular web usage may come to a crawl.

Aside from the console being a clue, you may also see a caution sign or a red circle with a white ‘x’ in it on the Web Developer toolbar.

For normal speeds when regularly browsing, just disable strict checking.