Smartphone displays have rapidly improved at every single price point. Inexpensive smartphones often compromised on display quality, which ended up hurting much of the overall experience. However, even inexpensive smartphones now ship with IPS displays and high enough resolutions to render text without overwhelming aliasing.

The Lumia 640 has a 5" 1280x720 IPS display. At 294 pixels per inch, it’s fairly sharp for a phone of this price. It’s obviously not some 2560x1440 flagship phone, but I never felt like text appeared fuzzy or highly aliased. To evaluated the aspects of display quality beyond what you’ll see on a spec sheet we turn to our standard smartphone display tests. As always, measurements are performed with X-Rite's i1Pro 2 spectrophotometer and SpectraCal's CalMAN 5 software, with the exception of contrast measurements which are done with an i1Display Pro colorimeter.

Display - Max Brightness

Display - Black Levels

Display - Contrast Ratio

437 nits is a fairly good result for peak brightness. It’s not quite as high as the 500 and 600nit displays that you’ll see on flagship phones, but it’s noticeably higher than many other devices at this price point. The contrast is also pretty good. While the black level isn’t even close to the lowest we’ve seen, when you consider that many devices use CABC to cheat on contrast it’s actually a relatively good result.

Display - White Point

Display - Grayscale Accuracy

The greyscale results on the Lumia 640 are exceptional. RGB balance is great at every shade of grey, with only a very slight shift toward blue. All of the errors will only be visible if you compare static images with a reference monitor. There’s not much more to be said, as the greyscale accuracy on this display is essentially perfect.

Display - Saturation Accuracy

The next test examines saturations of primary and secondary colors on the display in increments of 20%. In this test the Lumia 640 does very well. There are definitely some issues with blue and magenta, and the fact that cyan maxes out at 80% saturation, but the overall accuracy is very good.

Display - GMB Accuracy

The final display benchmark is the Gretag MacBeth ColorChecker test. This test examines colors that are commonly found in the real world, and it’s the best benchmark of display color rendition. A display can hit its saturation targets accurately but fail to reproduce these color mixtures properly.

Fortunately, the Lumia 640 suffers from no such issues. Most of the colors are reproduced with a high degree of accuracy, with the big errors being in shades of blue. Skin tones are very well reproduced, which is something I’ve seen other devices struggling with in recent reviews.

Overall, the Lumia 640’s display is very good, and I would go as far as to say that it’s one of the best displays on a phone at this price point. It performs well in every category, from brightness, to contrast, to color accuracy, and the resolution is high enough to keep everything looking fairly sharp. I think Lumia 640 users will be very happy with the display on their phone.

System Performance Camera Architecture and UX


View All Comments

  • WinterCharm - Tuesday, June 9, 2015 - link

    That's a really nice phone for the price! :D

    Great look and design, too!
  • JohanAnandtech - Tuesday, June 9, 2015 - link

    That kind of performance is going to get frustrating pretty quickly. Simply using some kind of navigation will quickly show the limits of using an A7 core. Reply
  • Wolfpup - Tuesday, June 9, 2015 - link

    On Android an A9 is dirt slow, while it's not bad running real Windows, much less Windows Phone.

    I've got a 520 and a 635, and the A7 isn't an issue in the 635 at all...at least not for the stuff most people do (certainly including navigation software). This 640 looks like an awesome extension...2x the RAM and a larger screen. Naturally it's coming out not long after I bought a spare 635 lol
  • jospoortvliet - Thursday, June 11, 2015 - link

    As the review makes clear - Windows Phone lost its advantages in terms of performance... Reply
  • jakoh - Thursday, June 11, 2015 - link

    The review compares the 640 to a bunch of high spec'd android and IOS, it doesnt show that WP can run smoothly even on crappy specs. Reply
  • leexgx - Thursday, June 11, 2015 - link

    i do agree i got a nokia 820 seems to work well
    But the Main problem with windows phones is lack of ram some times background tabs are deep suspended and take to long to restore i ignore any windows phone with 512mb of ram but would recommend 2GB as a minimum
  • darkich - Friday, June 12, 2015 - link

    You clearly didn't even read the article.

    The author was specifically comparing this to low end Motorola moto E performance wise.

    And he stated for several times that the whole OS and browser feel really slow in comparison.
  • SirPerro - Monday, June 15, 2015 - link

    "I mentioned in my Moto E review that for a long time I recommended that users who wanted a cheaper smartphone go with Windows Phone over Android, because at the time the options on Android were janky, slow, and offered a poor experience. I can’t make that recommendation anymore, because the app gap is still here, while the experience gap in favor of Windows Phone is gone."

    Article is loud and clear
  • Murloc - Tuesday, June 9, 2015 - link

    not really, I have a 635 and the experience is fluid. Reply
  • testbug00 - Tuesday, June 9, 2015 - link

    Really? L520 running quite smoothly through everything I throw at it (web browsing, some music playing, few notes in OneNote) andf it's a dual core A7 chipset (SD200).


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