What are the earliest versions of Internet Explorer, Firefox, Chrome, Safari and Opera that define window.Worker?

W3Schools states

Internet Explorer 10, Firefox, Chrome, Safari and Opera support Web workers.

But it is a bit vague for me. It does not state which versions of all the latter browsers have web workers. Also, does this mean that Internet Explorer 9 does not have web workers?

What are the earliest versions of Internet Explorer, Firefox, Chrome, Safari and Opera that define window.Worker?

W3Schools states

Internet Explorer 10, Firefox, Chrome, Safari and Opera support Web workers.

But it is a bit vague for me. It does not state which versions of all the latter browsers have web workers. Also, does this mean that Internet Explorer 9 does not have web workers?

• javascript
• patibility
• web-worker
• worker
• browser-support

• 4 caniuse./#feat=webworkers – ssbiswal1987 Commented Jan 28, 2015 at 10:51
• ^^ Lol - that is literally in my clipboard to paste, right now :D – Reinstate Monica Cellio Commented Jan 28, 2015 at 10:52
• Thanks, that's a helpful link, but the history does not reach back very far. It answers my question for IE, Opera Mini and the Android browsers, but not for Firefox, Chrome, Safari, and Opera. The page simply makes no statement of earlier browsers. Firefox 32 was released on the 2nd September 2014. I would bet that it did support web workers. – Malte Skoruppa Commented Jan 28, 2015 at 10:56
• 1 FYI, if you search on Google for the title you've given this question "Browser versions that support web workers?", the first result answers this. – James Donnelly Commented Jan 28, 2015 at 10:56
• 2 @MalteSkoruppa click "Show All". The answer I've posted lists the earliest versions supported as given when clicking the "Show All" button. – James Donnelly Commented Jan 28, 2015 at 10:57

1 Answer 1

From Can I Use...'s browser support for Web Workers:

The earliest versions which support Web Workers are:

• IE: 10
• Firefox: 3.5
• Chrome: 4
• Safari: 4
• Opera: 10.6

The Mozilla Developer Network's page on Web Workers also gives this information:

Feature         Chrome  Firefox (Gecko)  Internet Explorer  Opera  Safari (WebKit)
Basic support   4       Unknown (3.5)    10.0               10.6   4