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Google Says Adding Dark Mode To Apps Saves Battery (betanews.com)

Dark Mode is not just more aesthetically pleasing to many people, there are real battery-life boosts to be had -- and Google has the numbers to prove it. From a report: Touting the benefits of Dark Mode, Google showed that with screen brightness set to 50 percent, using YouTube with Dark Mode enabled resulted in 14 percent less battery usage. With screen brightness set to 100 percent, the saving jumps to 60 percent. These are not numbers to be sniffed at, but the biggest savings are to be seen on phones with AMOLED screens as anything that is black does not require pixels to be powered. Slides from the event show Google comparing the power usage of its own Pixel phone with an LCD iPhone 7. It shows a 63 percent battery saving when displaying a screenshot of Google Maps in normal and night mode.

61 comments

  1. Here's my question by slashmydots · · Score: 2

    Aren't normal screens backlit by an LED array and they're on constantly and black pixels just blocks and absorb or reflect the light? So making an app all black would simply make your phone warmer and the only solution is dimming it?

    1. Re:Here's my question by slinches · · Score: 3, Interesting

      They are backlit, but many new displays will dim or turn off the backlight in darker regions of the screen.

      --
      Knowledge Brings Fear
    2. Re: Here's my question by Anonymous Coward · · Score: 1

      AMOLED screens, such as those Samsung uses, do not have a backlight.

      It's why Samsung has massive screens and always on screen features without obliterating battery life.

      They are also better looking.

    3. Re:Here's my question by EvilSS · · Score: 2

      They are backlit, but many new displays will dim or turn off the backlight in darker regions of the screen.

      Are there any phones doing local dimming? Aren't the majority of LCD screens on phones edge lit?

      --
      I browse on +1 so AC's need not respond, I won't see it.
    4. Re:Here's my question by Anonymous Coward · · Score: 1

      OLED is per-pixel dimming.

    5. Re:Here's my question by fluffythedestroyer · · Score: 1

      To my understanding, LED when the color is black should require less or no power

    6. Re:Here's my question by ceoyoyo · · Score: 5, Informative

      LCD screens yes. Google is talking about their phone with an OLED screen. In OLED screens each pixel actually emits light, so turning it off (or down) saves energy.

    7. Re:Here's my question by Anonymous Coward · · Score: 0

      That is incorrect. First off its important to note that the energy required to change the liquid crystal alignment is quite low compared to the energy required to drive the backlight. Secondly, the default state with no power applied for a liquid crystal is transparent. When enough voltage is applied the polarization changes to make the liquid crystal opaque. So Black should technically require slightly more power than all white for a standard TN liquid crystal display. Again though, the power required to switch the LCD from transparent to opaque is quite small.

      The most important thing to remember is that an LCD panel has its backlight on at all times (ignoring dynamic contrast adjustment and local dimming for now). For all these reasons I would guess that a standard TN LCD screen wouldn't use much less power with a black background vs a white background. Any active emitting display such as OLED would see a benefit however since black equates to no light emission (compared to just blocked emission in the LCD panel).

      For more advanced displays that support local dimming/dynamic contrast I could see an improvement but it might come at the cost of visual fidelity. I have an older LCD panel that makes an absolute mess of dynamic contrast, making bright highlights in dark movie scenes appear dull/washed out. I can't imagine text being any better although I've not yet tried to read white text on a black background using such a display.

    8. Re:Here's my question by Anonymous Coward · · Score: 0

      OLED is per-pixel dimming

    9. Re:Here's my question by Anonymous Coward · · Score: 0

      Exactly, looks like someone (google) forgot there's 2 technologies and now all LCD displays get screwed.

    10. Re:Here's my question by infolation · · Score: 2

      Therefore we should watch films on our devices that are set predominately at night like Michael Mann's The Keep & Collateral, David Fincher's Se7en, Alien Vs Predator and The Evil Dead '91.

    11. Re:Here's my question by thegarbz · · Score: 1

      Actually LCDs save power too. The backlight is constant but most common LCD technologies will actually use energy to block the light away from its default transparent arrangement.

    12. Re:Here's my question by thegarbz · · Score: 1

      Aside from the fact that a large portion of phones on the market use OLED displays, and they consume power only to light up individual pixels having no backlight, you are right while you don't understand why.

      On an LCD you block light to make pixels black, this incidentally uses power, when the power is released the LCD becomes transparent. That said it isn't really relevant, it's a minor difference in power compared to an OLED panel.

    13. Re:Here's my question by Anonymous Coward · · Score: 0

      Any active emitting display such as OLED

    14. Re:Here's my question by ceoyoyo · · Score: 1

      LCDs use energy to twist the crystals and change the polarization. It's pretty arbitrary what the rest state is, but when I looked previously it seemed like most LCDs were set up for a default light blocking state. Might have changed of course, but it would seem to make sense to orient the polarizer so the rest state was whatever used the least energy on average.

    15. Re:Here's my question by KiloByte · · Score: 1

      I found a claim that new monitors started doing this around 2005, and that (post from 2013) "the majority of monitor sales" do this. So, it's good to have on real computers, too.

      I'd thus like to advertise a nice GTK2+3 theme: you want to "apt install darkcold-gtk-theme" (or darkmint if you prefer green). Despite no css skills I fixed them up, and since then the original author returned from years of no show. Somehow, any other theme shipped in Debian is at most mid-gray rather than actual black.

      --
      The creatures outside looked from Alt-Right to Antifa; but already it was impossible to say which was which.
    16. Re:Here's my question by Anonymous Coward · · Score: 0

      That claim can be refuted with a little reading. There are hardly any monitors with 'local dimming' and they are priced above $1000.

      Unless you're using an OLED display, or one with local dimmin, a dark theme does nothing to save energy

    17. Re:Here's my question by hawk · · Score: 1

      you can usually tell by looking when it's powered off.

      In high school, when a TI-30 (?) was the basic thing most had for Physics, we discovered that one of the variants had a case that would pop open easily.

      We would grab an unwatched phone, hide behind one of those dinosaurs that still walked the earth, and flip the display--giving our victim white numbers on a black background.

      Then we'd do something innocuous to get him to look at the calculator, and enjoy the ensuing panic . . .

      hawk

    18. Re:Here's my question by KiloByte · · Score: 1

      Unless you're using an OLED display, or one with local dimmin, a dark theme does nothing to save energy

      Right then. A dark theme is still good for your eyes during the night, so you save wetware even if no electricity.

      --
      The creatures outside looked from Alt-Right to Antifa; but already it was impossible to say which was which.
  2. Pixel 3 vs iPhone 7 by u19925 · · Score: 0

    Google comparing its $799 phone with $449 iPhone. WOW.

    1. Re:Pixel 3 vs iPhone 7 by Pieroxy · · Score: 0

      Google comparing its $799 phone with $449 iPhone. WOW.

      It's worse than that: Google comparing its $799 latest flagship phone with a 2 years old $449 iPhone.

      WOW indeed.

    2. Re:Pixel 3 vs iPhone 7 by Anonymous Coward · · Score: 1

      They compared the ORIGINAL Pixel to the iPhone 7, not the Pixel 3. Both phones came out in 2016, just one month apart. Please learn how to read before you start jerking your knee, you illiterate, raging fanboi.

  3. Duh by Anonymous Coward · · Score: 0

    Duh.. it is 2018. Why is it so tough to catch up with how LED works?

    1. Re:Duh by Anonymous Coward · · Score: 0

      They did a "Google Dark" years ago when dark became trendy. Physicists were quick to point out that an LCD screen showing black does not actually use less electricity.

      But now Google is talking about their phone with an OLED screen. In OLED screens each pixel actually emits light, so turning it off (or down) saves energy.

    2. Re:Duh by Anonymous Coward · · Score: 0

      All of android was "dark mode" up until about kitkat i believe, with lolipop they decided to copy apple with its ultra bright, white, pastel UIs.

      https://www.google.com/search?q=kitkat+screenshot&source=lnms&tbm=isch&sa=X

    3. Re:Duh by Anonymous Coward · · Score: 0

      It's kinda funny, google ditched the dark mode just as OLEDs were coming to prominence in the market. What a stupid move. Uses so much less energy to light 5% of the pixels on an OLED with a dark mode than to light up 95% of the pixels with a light mode.

      They didn't even think to make it toggleable, since they already had all the code for the dark mode, they could have put a option in the settings for a dark or light mode. Instead those who were dead set on a "dark" mode could go into accessibility and invert their screens, but of course that fu*ks up all the other colors than black, white or grays

  4. Why not offer the alternative up front? by Anonymous Coward · · Score: 0

    Not dark mode. Take the glaring blinding white of Google's home page makes it impossible to use inside a moviehouse or place of worship. Then ask us to preview Dark mode, after we've seenwhat 10% gray loks like while driving.

    Of course, I was kidding about the driving part; I was really texting.

    1. Re:Why not offer the alternative up front? by Anonymous Coward · · Score: 1

      Not dark mode. Take the glaring blinding white of Google's home page makes it impossible to use inside a moviehouse or place of worship...

      I have a better alternative up front.

      Don't use your fucking smartphone inside a moviehouse or place of worship.

    2. Re:Why not offer the alternative up front? by gerald.edward.butler · · Score: 1

      Yeah, but, can I eat popcorn and slurp a giant soda in church and stand up, raise my hands, and "speak" in tongues in a movie house? No? Then, why are you equating these two things?

    3. Re:Why not offer the alternative up front? by Anonymous Coward · · Score: 0

      Why don't you stop licking the assholes of random homeless drunks/addicts? That's just nasty! Fucking disgusting pig!
      goose, gander, sauce

    4. Re:Why not offer the alternative up front? by Anonymous Coward · · Score: 0

      Better question, why are you?

      You need to work on your reading comprehension, the post you replied to wasn't equating them.

  5. Oh really Google? by Anonymous Coward · · Score: 0

    Then why in the heck do you keep releasing all-white themes ala the new Google News? Maybe they should take their own advice.

  6. Genius by Anonymous Coward · · Score: 0

    > Touting the benefits of Dark Mode

    Neither google or slashdot used to render correctly with the white on dark grey desktop theme that my browser followed. The W3C were specific - setting either background or text colors means you must set them both.

    1. Re:Genius by DontBeAMoran · · Score: 1

      +1 million informative.

      --
      #DeleteFacebook
  7. WELL DUUUUH! by Anonymous Coward · · Score: 0

    I'm so sick of developers of all kinds making everything bright white, it's like staring into a flashlight sometimes it's so bright.

  8. Whoooo...Caahh... by xsspd2004 · · Score: 3, Funny

    Behold, the lack of power of the dark mode.

    --
    This is not an illusion, a rip-off, or a ninja technique!
    1. Re: Whoooo...Caahh... by Anonymous Coward · · Score: 0

      Vader was a tree hugging hippy?

  9. Racism by Anonymous Coward · · Score: 0

    Didn't Google just make their entire UI white?

  10. Duh by azcoyote · · Score: 2

    Now why has Google been burning my eyes and draining my batteries for years with their excessive use of all-white UXs?

    --
    Incipiamus, fratres, servire Domino Deo, quia hucusque vix vel parum in nullo profecimus.
  11. NO SHIT, SHERLOCK. by Anonymous Coward · · Score: 1

    Thanks for admitting your design team is being run by retards.

  12. Black Pixels by CanHasDIY · · Score: 1

    Whether or not black pixels save energy is the technological equivalent of the "are eggs healthy" debate:

    CRT screen? Black saves energy over white by not firing the beam at the dark pixels.

    LCD screen? White saves energy over black by not diffusing the backlight.

    OLED/AMOLED screen? Black saves energy by not lighting the pixel.

    So will the next revolution in display technology swing the pendulum back?

    --
    An enigma, wrapped in a riddle, shrouded in bacon and cheese
    1. Re:Black Pixels by thegarbz · · Score: 1

      LCD screen? White saves energy over black by not diffusing the backlight.

      Wrong. Most LCD configurations are transparent without energy and block light when energy is applied. The difference is only slight compared to OLED / CRT (unless you have a HDR display where the backlight adjusts depending on the content) but none the less black is actually the energy saving state not white.

    2. Re:Black Pixels by Anonymous Coward · · Score: 0

      If an LCD is transparent without energy, how is black (i.e. non-transparent) the energy saving state?

  13. Google late to the party by thegarbz · · Score: 2

    Google finally realises what Samsung users have known about for over 8 years thanks to a long history of using OLED displays.

    Seriously the energy saving benefits on not lighting the screen up actually made it into Samsung's variant of Eclair back in the day which gave you the option to use a dark mode or invert the display.

  14. Dark backgrounds... by DriveDog · · Score: 1

    ...are good with me. I've always hated white backgrounds and dark text/objects, on any screen, small or large. More eyestrain, less distinct objects/letters/whatever. So fine, make all the blank areas black. BTW, how do I get Slashdot to use a grey background???

    1. Re:Dark backgrounds... by Anonymous Coward · · Score: 0

      ...are good with me. I've always hated white backgrounds and dark text/objects, on any screen, small or large. More eyestrain, less distinct objects/letters/whatever. So fine, make all the blank areas black. BTW, how do I get Slashdot to use a grey background???

      The bolded section is the exact opposite of the truth. Dark text + light background is easier to focus on than light text + dark background. With a dark background in a dark room, your pupils dilate in order to read the light text, which makes the lettering blurry. With a light background, your pupils contract, bringing the letters into sharper focus.

    2. Re:Dark backgrounds... by Anonymous Coward · · Score: 0

      Dark text + light background is easier to focus on than light text + dark background.

      Maybe for you, not for me. Please don't speak for other people.

  15. Google Homepage by WankerWeasel · · Score: 2

    And yet their homepage is still white. A blog post some years ago calculated that a black Google homepage would save 750 megawatt-hours a year. http://ecoiron.blogspot.com/20...

    1. Re:Google Homepage by jafffacake · · Score: 1
    2. Re:Google Homepage by Anonymous Coward · · Score: 0

      And yet their homepage is still white.

      Black Homepages Matter!

  16. Blackberry beat them to it - how is this news? by Anonymous Coward · · Score: 0

    Big friggin' deal. All the QNX-based BB10 OS models had a black UI on OLED screens and thius was pointed out in reviews and sales literature at the time. This was one of the reasons I switched from Android and purchased my Z30, (Still happily running along too.)

    Ye gods people have short memories - or is it all this corporate newspeak constantly re-writing history and reality?

  17. dark google - blackle ! by jafffacake · · Score: 1

    Does anyone remember http://www.blackle.com/ ?

  18. Dark vs. Black Mode by Anonymous Coward · · Score: 0

    Some apps and Android custom firmware distinguish between a dark (grey) mode and a true black mode, where the text and graphic free areas are black-hole black and not just some dark shade of grey? Which is which?

  19. Um, duh? by sremick · · Score: 1

    Why is this news? We've known this for years:
    https://www.greenbot.com/artic...

    What next? We need Google to announce that water is wet so that people can finally go jump in a lake?

  20. Nothing new by Anonymous Coward · · Score: 0

    I find it funny that people have only just discovered all this like it's some sort of new thing. People always seem to accept the defautl themes on their desktops and devices, as if the default was the only choice and they should never befoul the designer's vision of the desktop.

    Since Windows98 I've been tweaking my themes to use far darker colours and tones as the bright white tones always hurt my eyes and gave me headaches. People always found it very odd that my Outlook windows where always dark grey backgrounds with light grey text but staring at a screen for 10+ hours a day I cannot sit staring at black text on white for hours without it giving me severe headaches. The fact that it also reduced burn on the old CRTs and now saves power on LCDs is nice fringe benefit. My terminals were always soft green on black, something I liked back on the old 1980's IBM terminals I first cut my teeth on, all my command lines and IDE windows are always softer light tones on black backgrounds, coders tend to perfer it as they can sit and stare for hours without straining their eyes. Now general users are learning that darker themes are better for their health with less eye strain and less headaches and better for the environment with less power required. I can imagine the huge boost to the environment if all the millions and millions of screens around the world simply toned down their screens by 30%.