How to enable WhatsApp dark mode on iOS?
Make sure that the device runs on iOS 11 or later versions. If you are not sure of your device version, you can follow these steps as outline below from How To Geek.

How To Check Your iOS Version
You can check which version of iOS you have on your iPhone, iPad, or iPod touch via the Settings app. To do so, navigate to Settings > General > About. You’ll see the version number to the right of the “Version” entry on the About page.

To enable WhatsApp dark mode in your iOS device, go to Settings > General > Accessibility > Display Accommodations > Invert Color > Smart Invert.
Now you have now enabled dark theme across all the apps in the device.
Then you will have to choose dark or no wallpaper for WhatsApp chat threads. Go to WhatsApp Settings > Wallpaper> None.

How to enable WhatsApp Dark Mode on Android?
Enabling WhatsApp dark mode on your android device is very similar as on iOS device, go to Settings > Display > Select theme > Dark.
Then once the dark mode is turned on, go to Settings > About phone and scroll down to Build number and tap on it seven times.
Now you will see a message pop-up saying Developers options is turned on. Tap on Override force-dark so that you can apply the dark theme to other apps.
Final step will be the same that you have performed on iOS device, go to WhatsApp Settings > Wallpaper > None.
So there you have it.

Regardless of whether you’re using an Android or iOS gadget, you can enable this mode in WhatsApp by following the steps outlined in this tutorial post.

Source: https://www.techsblog.com.ng/2019/09/11/whatsapp-dark-mode-how-to-enable-it-on-ios-and-android/

Alfred200825:
How to enable WhatsApp dark mode on iOS?
Make sure that the device runs on iOS 11 or later versions. If you are not sure of your device version, you can follow these steps as outline below from How To Geek.

How To Check Your iOS Version
You can check which version of iOS you have on your iPhone, iPad, or iPod touch via the Settings app. To do so, navigate to Settings > General > About. You’ll see the version number to the right of the “Version” entry on the About page.

To enable WhatsApp dark mode in your iOS device, go to Settings > General > Accessibility > Display Accommodations > Invert Color > Smart Invert.
Now you have now enabled dark theme across all the apps in the device.
Then you will have to choose dark or no wallpaper for WhatsApp chat threads. Go to WhatsApp Settings > Wallpaper> None.

How to enable WhatsApp Dark Mode on Android?
Enabling WhatsApp dark mode on your android device is very similar as on iOS device, go to Settings > Display > Select theme > Dark.
Then once the dark mode is turned on, go to Settings > About phone and scroll down to Build number and tap on it seven times.
Now you will see a message pop-up saying Developers options is turned on. Tap on Override force-dark so that you can apply the dark theme to other apps.
Final step will be the same that you have performed on iOS device, go to WhatsApp Settings > Wallpaper > None.
So there you have it.

Regardless of whether you’re using an Android or iOS gadget, you can enable this mode in WhatsApp by following the steps outlined in this tutorial post.

Source: https://www.techsblog.com.ng/2019/09/11/whatsapp-dark-mode-how-to-enable-it-on-ios-and-android/

Bless you. Love the dark mode on my iOS. Got some flaws tho

I don't see "override force dark" on developer

Op you have to be on android OS version 10 to have that feature

HisExcellence:
I don't see "override force dark" on developer

It is only available for android Q

KrazzyAndy:
Op you have to be on android OS version 10 to have that feature

Yes sir