False positives

[abrahamjuliot]

From what I see, the Chrome detection is based on storage quota < physical memory from here, but this condition is not exclusive to incognito mode. It's also in:

• Guest mode
• Privacy and security settings
  • Clear cookies and site data when you close all windows
  • Sites that clear cookies when you close them
• Anytime storage quota < jsHeapSizeLimit. Example: 3.99GB quota and 4GB jsHeapSizeLimit would get detected as incognito

---

Firefox can also produce false positives if the user disables Service Workers and Push API

• dom.serviceWorkers.enabled
• dom.push.enabled

[Joe12387]

I was not aware of the Guest mode false positive, thank you. Guest mode seems to effectively be incognito mode in everything but name so this is not surprising, but I do see this as a problem. Unfortunately quota < jsHeapSizeLimit has been the predominant method for Chrome for something like five years and I am yet to find an alternate method.

[abrahamjuliot]

Based on this line

settings.per_host_quota = settings.pool_size / 3;

I think this gives higher accuracy in Chrome. The real pool size is computed by the incognito_pool_size_ratio.
jsHeapSizeLimit / 3 just estimates the max value if the ratio was 1.

quota = (await navigator.storage.estimate()).quota;
memory = performance.memory.jsHeapSizeLimit / 3;

console.log([quota, memory])
console.log(quota < memory )

[abrahamjuliot]

Scratch that... it did not work on Android.

[jhk115]

@abrahamjuliot were you able to find a more reliable solution to this?

[Joe12387]

quota < jsHeapSizeLimit is no longer used, it's a little bit different now as of v1.2. See source for details.

[abrahamjuliot]

This works where device memory is reliable, but I like the v1.2 solution.

quota < (jsHeapSizeLimit / 3)
|| (quota / 1024 ** 3) < (navigator.deviceMemory / 3)

[coder0107git]

As far as I can tell the message from @devarya and @fastkood are scams or spam at the very least.

[coder0107git]

The message seem to be a widespread issue. The earliest message that I've found like the message from @devarya was from 4 hours ago. I spotted another almost identical message from @devarya here. When I looked into the message from @devarya the image linked to wwww [dot] bnb-chainexchaing [dot] online. I did a quick search and found about 600 message like that included that link. The strange thing is the earliest comment containing this link was from 4 hours ago. For whatever reason my account doesn't seem to be able to report these spam messages so I'm going to contact github support.