tl;dr;

Although it’s not supposed to be supported – it’s possible to know whether the Chrome console is opened or not.

Check it out.

Reddit discussion.

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Ever wondered if it’s possible to tell whether the browser’s Development-Tools are opened or not. Apparently it’s not possible in Chrome. And that’s a good thing, it’s no website business to know when I inspect their code.

The thing is… it is possible to tell.

When you run console commands it runs slower when the console is opened. That’s it. You simply run console.log and console.clear a few times and if it’s slower – than the console is open.

With this hack you can find out pretty reliably when the console is open and when it is closed.

Frankly, I don’t see how this can be mitigated without harming the performance of the browser. When the console is opened it has to be slower. Hence this hack will most likely continue to work. And I assume it’ll work similarly on other browsers and with other consoles.

Although others will claim otherwise, the only way I see this hack being used legitimately is by geeks to impress their peers.

Other than that the only valid reasons that I can think of are malicious, but I’m not gonna tell you how 😉

*

Making it perfectly accurate*

In the demo I’ve used a benchmark ratio of 1.6 to determine if the console is open or not. In a perfect implementation the ratio will be dynamic and will change between environments.

Currently if a user will open the page with the console already opened it’ll be detected only after the user will close it at least once.

It’ll be possible to create another independent benchmark to tell whether the console was opened when the page first loaded.

Demo is here