Dell UltraSharp U4021QW Monitor Review

Tested using Methodology v1.1
Reviewed Apr 14, 2021 at 09:22 am
Dell UltraSharp U4021QW Picture
7.5
Mixed Usage
8.1
Office
7.4
Gaming
7.4
Multimedia
7.7
Media Creation
5.5
HDR Gaming
Size 40"
Resolution 5120x2160
Max Refresh Rate
60 Hz
Pixel Type
IPS
Variable Refresh Rate
No VRR

The Dell UltraSharp U4021QW is a great office monitor with an impressive 5k x 2k resolution and a large 40 inch screen, making it very well-suited to productivity and multitasking. It also has some nice extra features, like Picture-in-Picture/Picture-by-Picture and KVM switch capability, but lacks others like HDR support, Black Frame Insertion (BFI), and variable refresh rate (VRR). It has a low contrast ratio, typical of an IPS panel, but its viewing angles are great, so the image stays accurate when viewed from the sides. It also has an incredible color gamut. It gets decently bright, enough to overcome glare in moderate lighting conditions, but it may struggle in very bright rooms. Its response time is decent; fine for casual gaming, but probably not fast enough for more competitive gamers.

Our Verdict

7.5 Mixed Usage

The Dell U4021QW is a good all-around monitor. The large size is well-suited to productivity or immersing yourself in a movie or game, and its exceptionally high resolution delivers a crisp image. It also has an incredible color gamut for content creators working in the sRGB color space. While its response time is fine for casual gaming, it may be too slow for serious gamers, and unfortunately, there's no VRR support.

Pros
  • 5k x 2k resolution delivers a super crisp image.
  • Incredible color gamut.
  • Wide viewing angles.
  • Large screen is ideal for multitasking.
Cons
  • Low contrast ratio.
  • No HDR, VRR, or BFI.
  • May struggle with glare in very bright rooms.
8.1 Office

The Dell U4021QW is a great office monitor. Its uniquely large size and resolution let you juggle multiple windows, and it comes with extra features like PIP/PBP and KVM switch. Text clarity is exceptional, and it has great viewing angles, making it easier to share content. Unfortunately, its peak brightness is only decent, so glare may be an issue in very bright, sunny rooms.

Pros
  • 5k x 2k resolution delivers a super crisp image.
  • Text looks exceptionally clear.
  • Wide viewing angles.
  • Large screen is ideal for multitasking.
Cons
  • Low contrast ratio.
  • May struggle with glare in very bright rooms.
7.4 Gaming

The Dell U4021QW is decent for gaming. It's limited to a 60Hz refresh rate, and while its response time is decent, it may be too slow for more serious gamers. On the upside, the input lag is low, and it has wide viewing angles. Also, its large size is perfect for immersing yourself in a game.

Pros
  • 5k x 2k resolution delivers a super crisp image.
  • Low input lag.
  • Large screen size feels immersive.
Cons
  • Low contrast ratio.
  • Doesn't support VRR.
  • Response time is only decent.
7.4 Multimedia

The Dell U4021QW is decent for multimedia. The size and resolution are incredible for watching movies or other content, delivering plenty of space and a super crisp image. Unfortunately, it has a sub-par contrast ratio, so black looks more like gray in the dark.

Pros
  • 5k x 2k resolution delivers a super crisp image.
  • Incredible color gamut.
  • Wide viewing angles.
Cons
  • Low contrast ratio.
  • Doesn't support HDR.
  • May struggle with glare in very bright rooms.
7.7 Media Creation

The Dell U4021QW is a good media creation monitor. It has an incredible color gamut, including great coverage of the Adobe RGB color space used in photo editing. The size is great for opening multiple windows, and its exceptional 5k x 2k resolution delivers a crisp image. Unfortunately, it has a low contrast ratio, so blacks look more grayish in the dark.

Pros
  • 5k x 2k resolution delivers a super crisp image.
  • Incredible color gamut.
  • Large screen is ideal for multitasking.
Cons
  • Low contrast ratio.
  • May struggle with glare in very bright rooms.
5.5 HDR Gaming
  • 7.5 Mixed Usage
  • 8.1 Office
  • 7.4 Gaming
  • 7.4 Multimedia
  • 7.7 Media Creation
  • 5.5 HDR Gaming

Test Results

perceptual testing image
Design
Design
Style
Curved Yes
Curve Radius 2500R
Weight (without stand)
20.9 lbs (9.5 kg)
Weight (with stand)
30.4 lbs (13.8 kg)

The Dell U4021QW has a curved ultrawide screen and a similar overall design as other UltraSharp monitors. It's sleek and simple, with thin black bezels and a silver body, and it should look great whether you're working in the office or using it at home.

Design
Stand
Width
15.2" (38.5 cm)
Depth
9.7" (24.7 cm)

The Dell U4021QW has a similar trapezoidal stand as other Dell UltraSharps like the Dell U3818DW. It supports the monitor well and doesn't take up too much space.

6.4
Design
Ergonomics
Height Adjustment
4.7" (12.0 cm)
Switch Portrait/Landscape No
Swivel Range -35° to 35°
Tilt Range -20° to 5°

The ergonomics are good, although it scores lower because it can't rotate into portrait mode. That's because of its ultrawide screen, though, which you likely wouldn't want to rotate anyway.

Design
Back
Wall Mount VESA 100x100

The back of the monitor is clean and simple. There's a cutout in the stand for cable management.

Design
Borders
Borders
0.4" (1.1 cm)
Design
Thickness
Thickness (with stand)
8.3" (21.1 cm)
Thickness (without stand)
4.0" (10.1 cm)

Because of the screen's curve, it has a somewhat thicker profile, but all things considered, it's quite thin and doesn't require a deep desk.

7.0
Design
Build Quality

The Dell U4021QW feels fairly well-built. It's very heavy, and the plastic is quite rigid, and the feet grip very well, so you're unlikely to move it by accident. However, there's some flex where the panel meets the plastic backing all around the monitor that makes it feel less well put together.

Picture Quality
5.9
Picture Quality
Contrast
Native Contrast
943 : 1
Contrast With Local Dimming
N/A

The Dell U4021QW has a sub-par contrast ratio, although it's about expected for an IPS panel. Our unit is slightly lower than the advertised 1000:1, but contrast can vary between individual units.

0
Picture Quality
Local Dimming
Local Dimming
No
Backlight
Edge

This monitor doesn't have a local dimming feature. The video above is provided for reference only.

7.1
Picture Quality
SDR Peak Brightness
SDR Real Scene
256 cd/m²
SDR Peak 2% Window
279 cd/m²
SDR Peak 10% Window
279 cd/m²
SDR Peak 25% Window
280 cd/m²
SDR Peak 50% Window
280 cd/m²
SDR Peak 100% Window
280 cd/m²
SDR Sustained 2% Window
278 cd/m²
SDR Sustained 10% Window
279 cd/m²
SDR Sustained 25% Window
279 cd/m²
SDR Sustained 50% Window
279 cd/m²
SDR Sustained 100% Window
280 cd/m²
SDR ABL
0.000

SDR peak brightness is decent, although it's slightly lower than the advertised 300 nits. It stays very consistent with difference scenes, though, which is great.

We measured the SDR brightness after calibration using the 'Custom Color' Picture Mode, with Brightness set to max.

0
Picture Quality
HDR Peak Brightness
HDR Real Scene
N/A
HDR Peak 2% Window
N/A
HDR Peak 10% Window
N/A
HDR Peak 25% Window
N/A
HDR Peak 50% Window
N/A
HDR Peak 100% Window
N/A
HDR Sustained 2% Window
N/A
HDR Sustained 10% Window
N/A
HDR Sustained 25% Window
N/A
HDR Sustained 50% Window
N/A
HDR Sustained 100% Window
N/A
HDR ABL
N/A

The Dell U4021QW doesn't support HDR.

8.0
Picture Quality
Horizontal Viewing Angle
Color Washout From Left
43 °
Color Washout From Right
45 °
Color Shift From Left
49 °
Color Shift From Right
51 °
Brightness Loss From Left
49 °
Brightness Loss From Right
51 °
Black Level Raise From Left
70 °
Black Level Raise From Right
70 °
Gamma Shift From Left
40 °
Gamma Shift From Right
41 °

The Dell U4021QW has great horizontal viewing angles, which is good for sharing content and ensures the edges of the screen remain accurate when sitting up close.

7.1
Picture Quality
Vertical Viewing Angle
Color Washout From Below
33 °
Color Washout From Above
30 °
Color Shift From Below
38 °
Color Shift From Above
33 °
Brightness Loss From Below
36 °
Brightness Loss From Above
32 °
Black Level Raise From Below
70 °
Black Level Raise From Above
70 °
Gamma Shift From Below
43 °
Gamma Shift From Above
36 °

Verticle viewing angles are decent, but you still lose some image accuracy when viewing from above or below.

8.5
Picture Quality
Gray Uniformity
50% Std. Dev.
2.994 %
50% DSE
0.122 %
5% Std. Dev.
0.398 %
5% DSE
0.032 %

The Dell U4021QW has excellent gray uniformity, although this can vary between units. The corners and edges are a bit darker, and there's some slight dirty screen effect, but it should be very hard to notice with actual content. In near-dark scenes, the uniformity is even better.

6.8
Picture Quality
Black Uniformity
Native Std. Dev.
1.434 %
Std. Dev. w/ L.D.
N/A

The Dell U4021QW scores a bit higher for black uniformity than it should. Due to its size and the screen's curve, the corners of our test photo are cropped, but as you can see here, there's noticeable backlight bleed in the corners. The whole screen looks more gray than black, and there's a bit of clouding throughout, as well as blooming around the test cross. Keep in mind that black uniformity may vary between units.

9.1
Picture Quality
Pre Calibration
Picture Mode
Color Space (sRGB)
Luminance
210 cd/m²
Luminance Settings
75
Contrast Setting
75
RGB Controls
Default
Gamma Setting
No Gamma Setting
Color Temperature
6281 K
White Balance dE
1.50
Color dE
0.99
Gamma
2.16

The Dell U4021QW has fantastic out-of-the-box color accuracy, but this can vary between individual units. Most colors are very accurate, and the white balance is excellent too. Gamma follows the curve fairly well, although very dark and very bright scenes are a bit over-brightened. The color temperature is close to our 6,500K target but a bit on the warm side.

9.7
Picture Quality
Post Calibration
Picture Mode
Custom Color
Luminance
100 cd/m²
Luminance Settings
28
Contrast Setting
75
RGB Controls
98-97-100
Gamma Setting
No Gamma Setting
Color Temperature
6456 K
White Balance dE
0.65
Color dE
0.31
Gamma
2.18

After calibration, accuracy is incredible. Any inaccuracies shouldn't be noticeable to the naked eye. Gamma is improved overall, and the color temperature is close to perfect.

You can download our ICC profile calibration here. This is provided for reference only and shouldn't be used, as the calibration values vary per individual unit due to manufacturing tolerances, even for the same model.

9.4
Picture Quality
SDR Color Gamut
sRGB xy
100.0 %
Adobe RGB xy
88.5 %
sRGB Picture Mode
Custom Color
Adobe RGB Picture Mode
Custom Color

The monitor has an exceptional SDR color gamut. It has full coverage of the sRGB color space and excellent coverage of the wider Adobe RGB used in photo editing. It's also advertised as having 98% coverage of the DCI P3 color space, but this isn't something that we test outside of HDR, which isn't supported on this monitor.

9.6
Picture Quality
SDR Color Volume
sRGB In ICtCp
98.2 %
Adobe RGB In ICtCp
93.2 %
sRGB Picture Mode
Custom Color
Adobe RGB Picture Mode
Custom Color

SDR color volume is superb. It can produce a wide range of bright colors. It only really struggles a bit with deep, dark colors due to its limited contrast ratio.

0
Picture Quality
HDR Color Gamut
Wide Color Gamut
N/A
DCI P3 xy
N/A
Rec. 2020 xy
N/A
DCI P3 Picture Mode
No HDR
Rec. 2020 Picture Mode
No HDR
0
Picture Quality
HDR Color Volume
DCI-P3 In ICtCp
N/A
Rec. 2020 In ICtCp
N/A
DCI P3 Picture Mode
No HDR
Rec. 2020 Picture Mode
No HDR
10
Picture Quality
Image Retention
IR After 0 Min Recovery
0.00 %
IR After 2 Min Recovery
0.00 %
IR After 4 Min Recovery
0.00 %
IR After 6 Min Recovery
0.00 %
IR After 8 Min Recovery
0.00 %
IR After 10 Min Recovery
0.00 %

There are no signs of temporary image retention, but this may vary between units.

9.8
Picture Quality
Gradient
Color Depth
10 Bit

Gradient performance is incredible. You shouldn't notice any banding.

10
Picture Quality
Color Bleed
Pixel Row Error
0.001 %
Pixel Column Error
0.001 %

There's no noticeable color bleed on this monitor.

6.7
Picture Quality
Reflections
Screen Finish
Matte
Total Reflections
6.6 %
Indirect Reflections
3.2 %
Calculated Direct Reflections
3.4 %

The Dell UltraSharp U4021QW has adequate reflection handling, but we don't recommend placing it opposite a window or direct lighting.

9.5
Picture Quality
Text Clarity
Sub-Pixel Layout
RGB

Text clarity is exceptional. The monitor's 5k resolution produces very clear text. Enabling ClearType (top photo) makes text look a little bolder.

Motion
7.2
Motion
Response Time @ Max Refresh Rate
Best Overdrive Setting
Normal
Rise / Fall Time
6.5 ms
Total Response Time
18.7 ms
Overshoot Error
7.5 %
Dark Rise / Fall Time
6.6 ms
Dark Total Response Time
20.3 ms
Dark Overshoot Error
12.5 %

Overdrive SettingResponse Time ChartResponse Time TablesMotion Blur Photo
NormalChartTablePhoto
FastChartTablePhoto

The Dell U4021QW has a decent response time at its max refresh rate. It should be fine for casual gaming but wouldn't cut it for more competitive gamers. The recommended overdrive setting is 'Normal' because it's reasonably fast and has much less overshoot than the 'Fast' setting.

7.2
Motion
Response Time @ 60Hz
Best Overdrive Setting
Normal
Rise / Fall Time
6.5 ms
Total Response Time
18.7 ms
Overshoot Error
7.5 %
Dark Rise / Fall Time
6.6 ms
Dark Total Response Time
20.3 ms
Dark Overshoot Error
12.5 %

The max refresh rate is 60Hz.

10
Motion
Image Flicker
Flicker-Free Yes
PWM Dimming Frequency
0 Hz

The Dell U4021QW has a flicker-free backlight, which can help reduce eye strain.

0
Motion
Black Frame Insertion (BFI)
Black Frame Insertion (BFI)
No BFI
BFI Maximum Frequency
N/A
BFI Minimum Frequency
N/A

This monitor doesn't have a Black Frame Insertion (BFI) or backlight strobing feature.

5.9
Motion
Refresh Rate
Native
60 Hz
Max Refresh Rate
60 Hz
Variable Refresh Rate
No
FreeSync
No
G-SYNC
No
VRR Maximum
N/A
VRR Minimum
No VRR
VRR Supported Connectors No VRR

The Dell U4021QW has a maximum refresh rate of 60Hz, which should be fine for most people using it mostly for productivity. The max refresh rate over HDMI is only 30Hz, though, so you need to use DisplayPort to get 60Hz. Unfortunately, it doesn't support VRR to reduce screen tearing in games.

Inputs
9.0
Inputs
Input Lag
Native Resolution
8.9 ms
Native Resolution @ 60Hz
8.9 ms
Variable Refresh Rate
N/A
Variable Refresh Rate @ 60Hz
N/A
10 Bit HDR
N/A
Black Frame Insertion (BFI)