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review with features, price and specifications

22 mayo, 2021

LG renewed its most economical range, the one formed by the K line, last February with two phones, the LG K40 and the LG K50, two devices with which the company intends to gain a foothold in the much-disputed entry range, where more and more manufacturers are launching a variety of phones to adapt to the needs of different audiences

Does the LG K40 stand out in it? Artificial intelligence is the hallmark of the smartphone, but it is not the only one. We analyze it thoroughly to discover what it hides.

LG K40 datasheet

LG K40


IPS 5.7 inch HD + (1440 x 720 pixels) 18: 9


Eight cores at 2GHz (MT6762)




32GB MicroSD up to 2TB


16 MP f / 2.2 with AI


8 MP


Android 8 Oreo


153.0 x 71.9 x 8.3 mm
145 grams


3,000 mAh


WiFi 802.11 a / b / g / n / ac, Bluetooth 5.0 BLE, NFC, 3.5mm jack, USB-B 2.0


Fingerprint reader
MIL-STD 810G protection
Surround Sound DTS: X 3D
Google Lens
Dual sim
Google Assistant button


179 euros

Lg K40 New Moroccan Blue 5.7" 2gb / 32gb Dual Sim

Lg K40 New Moroccan Blue 5.7 “2gb / 32gb Dual Sim

Design: In the absence of one, two LEDs

Lg K40 8 Jpeg

What seemed like the great novelty of high-end mobiles has also ended up reaching the entry range. We refer to the 18: 9 screen that is becoming more and more frequent, and from which the LG K40 does not escape either, giving it a certain air of modernity. The result is a narrower and longer mobile, which is comfortable to operate with one hand.

Its measurements contribute to this: 153.0 x 71.9 x 8.3 mm, and its weight of 145 grams, which makes it feel light. The rounded edges are a plus since gains in ergonomics by giving it a comfortable and practical grip, being very easy to hold, although, yes, the metal finish can sometimes be somewhat slippery depending on which surfaces.

Without notch, the screen comes with two LEDs, one for the front camera and the second for notifications

There is no notch here. The IPS screen is 5.7 inches with HD + resolution (1440 x 720). With hardly any frames on the sides, the same does not happen on the chin, with an important black stripe that also appears in the upper area. Here we have everything: the front camera is joined by an LED flash that (on paper) allows better selfies to the detriment of adding more things on the screen, although in practice this is not how we will see later.

But it does not arrive alone, since a second red LED for notifications. Upset? Perhaps a bit, as well as visually unattractive, although it can be disabled from the phone’s Settings.

The mobile comes in a single color, New Moroccan Blue (Matt), and has a 2.5D glass back, which gives it a plus of distinction, in addition to greater protection, since it better absorbs the impact against possible falls according to LG . But be careful, because it is a magnet for footprints, that appear at the slightest occasion. It is appreciated to find a microfiber in the box to try to keep them away as much as possible.

Lg K40 22 Jpeg

If we turn it over, on the back we find the camera module located in vertical position centered on the upper area of ​​the phone. And yes, we speak in the singular, because the LG K40 only has a rear camera. Weird at this point? It may seem like it, but considering that we are facing an entry range, it would be unfair to demand much more from you.

Inside the camera module is the LED flash and, a few millimeters away, the fingerprint reader. As we have seen on other occasions, this location is not ideal since, being so close to the lens, it is very likely that we constantly stain it every time we try to unlock the mobile.

Lg K40 20 Jpeg

We go to the sides. On the right we find the terminal’s on and off button, while on the left are the volume buttons and a button dedicated to Google Assistant, in addition to the trays for SIM and micro SD cards. At the bottom, the speaker, the 3.5 mm headphone port and the USB-B 2.0

LG K40




HUAWEI Y6 (2018)



5.7 inch

5.6 inch

5.7 inch

5.65 inch

5.7 inch

5.7 inch






75.4 %%



153 x 71.9 x 8.3 mm

151.3 x 70.1 x 8.2 mm

151.4 x 70.6 x 7.5 mm

151 x 71.9 x 7.6 mm

152.4 x 73 x 7.8 mm

154 x 72 x 8.9 mm


145 grams

147 grams

140 grams

149 grams

150 grams

156 grams


3,000 mAh

3,000 mAh

3,100 mAh

3,000 mAh

3,000 mAh

3,300 mAh

When facing it with other current models with a similar screen, we can verify that it is one of the ones with the best body / screen ratio, with 76.2%, only surpassed by the ZTE Blade V9, with 78.4%. Of course, the data is nothing to write home about, since we are talking that 23.8% of the front is intended for frames.

In addition, it is also one of the lightest, with 145 grams (also surpassed by the ZTE with 140 grams) offering a 3,000 mAh battery similar to the mobiles with which we have compared it, only surpassed (again) by the ZTE Blade. V9 with 3,100 mAh and the Sony Xperia L3 with 3,300 mAh. Therefore, we can affirm that the compaction work of the LG K40 is really good.

The mobile has MIL-STD-810G military certification that protects it against extreme conditions of temperature, humidity and against certain types of falls and shocks

Also highlights its MIL-STD-810G military certification, frequent in the high ranges of the brand, but not in the entry-level ones. In fact, it is the first phone in its class to have this certification used by the United States Department of Defense on equipment used by its soldiers. To do this, they subject mobile phones to different tests with extreme conditions of temperature, rain and humidity, solar radiation, freezing or mechanical vibrations, among others.

In short, the LG K40 does not attract attention especially in terms of design, since it follows the line of many of the mobiles that we currently find on the market, although it is quite functional and you cannot put too many drawbacks on it as it does its job. It is surprising, that yes, that when manufacturers look for the long-awaited “all screen” mode with solutions such as the notch or the retractable camera, LG not only inserts the camera in the upper frame, but also adds the notification LED and the flash to the front camera. They say that less is more, and here it would have worked without a doubt.

18: 9 screen with improved clarity

Lg K40 22

The LG K40 mounts a 5.7-inch IPS / LCD screen with 18: 9 format and HD + resolution, which translates into 1440 x 720 pixels with a density of 282 dots per inch, a figure that can be greatly improved and that results in a level of sharpness below the average, with the pixels becoming visible depending on what is displayed on the screen.

As we say, the resolution is really at the limit, with an HD + that is somewhat short. An increase in the figure of 282 dpi would have been appreciated, although logically this would have entailed a greater drain on the battery. Acceptable? Considering the league we’re in, yes. And don’t try to activate it with a double click, because it doesn’t work here.

The screen has an HD + resolution, which translates to 1440 x 720 pixels with a density of 282 dots per inch, with a level of sharpness below average.

In terms of colors, the LG K40 screen offers correct colors although sometimes they can seem somewhat saturated. In the Settings we find different options to regulate the view of the screen, but perhaps more than improving it, it may make it worse. Thus, there is the option “high contrast” that tries to resemble the dark mode, taking the background of the screen to black; the inversion of color (for people with vision problems) or the gray scale that brings the mobile to these tones.

Lg K40 Color Screen Settings

But perhaps the most surprising are the Screen color settings. There we can choose between Protanomaly (Red-green), Deuteranomaly (Red-green) or Tritanomaly (Blue-yellow). Depending on the one you choose, you will have as a result dull or exaggerated colors that become unpleasant to look at. So the best option, without a doubt, is the one that is activated by default in the factory settings.

Lg K40 Glossy On the left in direct sunlight; right in the shade.

The view from different angles can be improved, since reflections appear, as does the tactile response, where we have found some delay in the response.

The brightness has not convinced us. With a correct performance indoors, outdoors things change and in sunlight it costs you a lot of work. It can be automatically adjusted so that it changes only by adapting to the ambient light, something that it does, although it takes a few seconds to give an optimal response. Of course, under direct sunlight, the mobile screen is the closest thing to a mirror. It is difficult to see something in it even adjusting the brightness to 100% and you have to make a shadow on the panel to be able to see anything on the mobile.

DTS: X 3D surround sound offers virtual multi-channel sound through 360-degree objects, even though the volume remains too tight

The DTS: X 3D surround sound is perhaps one of the strengths of the LG K40 as it is capable of offering a virtual multi-channel sound for 360 degree objects. What does this translate to? According to the manufacturer, in an enveloping and immersive sensation in any video you are watching, whether with headphones or speakers, although the reality is somewhat different.

If you try to listen to any audio or video without headphones, the feeling is constantly wanting to turn up the volume because it is not heard well, which ends up generating a certain feeling of helplessness. Perhaps the location of the speakers, at the bottom, increases this feeling, forcing the phone to be tilted so that the audio reaches better. In the end, every time I tried I had to end up resorting to headphones, where the sound is much better.

Short performance with AI

Lg K40 Profile

At the controls of the LG K40 is the MediaTek Helio P22 (MT6762) processor, a chip that saw the light in May of last year intended for the mid-range with interesting features on board. Perhaps the most prominent is the presence of the artificial intelligence that we find in the LG K40. In fact, it offers dedicated AI functions thanks to the Neuropilot architecture that allows a faster interface with greater efficiency and less battery consumption, according to LG.

The CPU is the …