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Dell S2421H Monitor Review

Tested using Methodology v1.1
Reviewed Dec 03, 2021 at 10:53 am
Dell S2421H Picture
6.9
Mixed Usage
7.1
Office
7.3
Gaming
6.8
Multimedia
6.7
Media Creation
5.2
HDR Gaming
Size 24"
Resolution 1920x1080
Max Refresh Rate
75 Hz
Pixel Type
IPS
Variable Refresh Rate
FreeSync

The Dell S2421H is a basic 24 inch monitor with a 1080p panel and very few additional features. It's part of Dell's S Series of monitors, which are mainly entry-level to mid-range monitors designed for everyday use with a few advanced gaming features. The small screen and relatively low pixel density result in only decent text clarity. However, it has good visibility in most environments, with wide viewing angles, satisfactory peak brightness, and very good reflection handling. It has superb low input lag, a good response time, and it supports FreeSync, but it has a relatively low refresh rate, which might disappoint some gamers. Unfortunately, it has terrible ergonomics, so it's hard to place it in an ideal viewing position, and it has low contrast, so it doesn't look as good in a completely dark room.

Our Verdict

6.9 Mixed Usage

The Dell S2421H is an okay monitor for most uses. It's decent for office use, with excellent gray uniformity, wide viewing angles, and good visibility in bright settings. It's also decent for gaming, with low input lag, a good response time, and FreeSync support. It's okay for watching videos or media creation, as it has an excellent SDR color gamut, good gradient handling, and satisfactory accuracy out of the box. Unfortunately, it doesn't support HDR.

Pros
  • Image remains accurate at an angle.
  • Superb low input lag.
  • Very good reflection handling.
  • Excellent gray uniformity.
Cons
  • Terrible ergonomics.
  • Mediocre contrast ratio.
  • Small, low-resolution screen.
  • No DisplayPort input.
7.1 Office

The Dell S2421H is decent for office use. The relatively low pixel density results in only decent text clarity, and it's a bit small for multitasking. On the other hand, it has excellent gray uniformity, wide viewing angles, and good visibility, with satisfactory peak brightness and very good reflection handling. Sadly, it has terrible ergonomics, so it's hard to place it in an ideal viewing position.

Pros
  • Image remains accurate at an angle.
  • Very good reflection handling.
  • Excellent gray uniformity.
Cons
  • Terrible ergonomics.
  • Small, low-resolution screen.
  • No DisplayPort input.
7.3 Gaming

The Dell S2421H is a decent monitor for gaming. It has superb low input lag, meaning you can respond quickly to the action on-screen. It also has a good response time, but there's some noticeable blur behind fast-moving objects. It supports FreeSync variable refresh rate technology, which helps reduce screen tearing. Unfortunately, the relatively small screen doesn't deliver a very immersive gaming experience, and the response time at 60Hz is just okay.

Pros
  • Superb low input lag.
  • FreeSync support.
  • Good response time at the max refresh rate.
Cons
  • Terrible ergonomics.
  • Mediocre contrast ratio.
  • Small, low-resolution screen.
  • No DisplayPort input.
6.8 Multimedia

The Dell S2421H monitor is just okay for watching videos. The relatively small size doesn't deliver a very immersive movie-watching experience. However, it has wide viewing angles, great if you're not sitting directly in front or if you're sharing the screen with someone else. It has very good reflection handling, low input lag, and excellent gray uniformity. Unfortunately, it doesn't support HDR, and it has a low contrast ratio, so it's not a good choice for a dark room.

Pros
  • Image remains accurate at an angle.
  • Excellent SDR color gamut.
  • Excellent gray uniformity.
Cons
  • Terrible ergonomics.
  • Mediocre contrast ratio.
  • No HDR support.
  • Small, low-resolution screen.
  • No DisplayPort input.
6.7 Media Creation

The Dell S2421H monitor is just alright for media creation. It has good viewing angles, excellent gray uniformity, and good gradient handling. It also has an excellent SDR color gamut, but it's limited to the sRGB color space. Sadly, the small, low-resolution screen means you won't be able to see much of your workflow at once. It also has terrible ergonomics, so you can't easily place it in an ideal viewing position or turn it to share the screen with others.

Pros
  • Image remains accurate at an angle.
  • Excellent SDR color gamut.
  • Excellent gray uniformity.
Cons
  • Terrible ergonomics.
  • Mediocre contrast ratio.
  • Small, low-resolution screen.
  • No DisplayPort input.
5.2 HDR Gaming
  • 6.9 Mixed Usage
  • 7.1 Office
  • 7.3 Gaming
  • 6.8 Multimedia
  • 6.7 Media Creation
  • 5.2 HDR Gaming
  1. Updated Dec 03, 2021: Review published.
  2. Updated Dec 01, 2021: Early access published.

Test Results

perceptual testing image
Design
Design
Style
Curved No
Curve Radius Not Curved
Weight (without stand)
7.4 lbs (3.3 kg)
Weight (with stand)
8.7 lbs (3.9 kg)

The Dell S2421H has a simple design, with very thin bezels on three sides and a white finish on the back. It looks great in any environment, and like most Dell monitors, it's decently well-built.

Design
Stand
Width
9.8" (24.8 cm)
Depth
6.1" (15.5 cm)

The Dell S2421H has a simple stand. It doesn't support the monitor very well, though, as it wobbles a lot. The stand has a relatively large footprint, but it's thin, and you can still place small objects on the base.

1.5
Design
Ergonomics
Height Adjustment
0.0" (0.0 cm)
Switch Portrait/Landscape No
Swivel Range No swivel
Tilt Range -20° to 5°

Unfortunately, the Dell S2421H has a very basic stand with terrible ergonomics, so it's hard to place it in an ideal viewing position. The Dell S2421HS variant has much better ergonomics, with height, pivot (rotation), swivel, and tilt adjustments.

Design
Back
Wall Mount VESA 100x100

The back of the monitor is very plain. There's a hole in the stand for very basic cable management.

Design
Borders
Borders
0.2" (0.5 cm)

The borders of the monitor are very thin on three sides.

Design
Thickness
Thickness (with stand)
4.4" (11.3 cm)
Thickness (without stand)
1.9" (4.9 cm)
7.0
Design
Build Quality

The Dell S2421H has just decent build quality. It's entirely plastic, and there's some flex in the back panel, as well as along the bottom bezel. The stand feels pretty cheap, though, and the monitor wobbles quite a bit.

Picture Quality
6.2
Picture Quality
Contrast
Native Contrast
1,126 : 1
Contrast With Local Dimming
N/A

Unfortunately, as expected for an IPS monitor, the Dell S2421H has mediocre contrast. This isn't really noticeable in a bright room, but blacks look gray if you're in a dark room. Contrast varies between individual units, but we don't expect IPS panels to get much better than this.

0
Picture Quality
Local Dimming
Local Dimming
No
Backlight
Edge

Unfortunately, this monitor doesn't have a local dimming feature. We still film this video so you can see how the backlight performs on the monitor and compare it to other monitors with a local dimming feature.

7.0
Picture Quality
SDR Peak Brightness
SDR Real Scene
250 cd/m²
SDR Peak 2% Window
265 cd/m²
SDR Peak 10% Window
266 cd/m²
SDR Peak 25% Window
266 cd/m²
SDR Peak 50% Window
267 cd/m²
SDR Peak 100% Window
267 cd/m²
SDR Sustained 2% Window
265 cd/m²
SDR Sustained 10% Window
266 cd/m²
SDR Sustained 25% Window
266 cd/m²
SDR Sustained 50% Window
266 cd/m²
SDR Sustained 100% Window
266 cd/m²
SDR ABL
0.000

The Dell S2421H has satisfactory peak brightness in SDR. It's bright enough to overcome glare in most rooms, and there's no noticeable variation in brightness with different content. The real scene peak brightness is exactly the same as the advertised peak brightness.

We measured the SDR peak brightness after calibration in 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

This monitor doesn't support HDR.

7.6
Picture Quality
Horizontal Viewing Angle
Color Washout From Left
36°
Color Washout From Right
39°
Color Shift From Left
48°
Color Shift From Right
50°
Brightness Loss From Left
44°
Brightness Loss From Right
46°
Black Level Raise From Left
70°
Black Level Raise From Right
70°
Gamma Shift From Left
35°
Gamma Shift From Right
36°

The Dell S2421H monitor has good horizontal viewing angles, as expected for an IPS panel. The image remains mostly accurate at a wide angle, but it's a bit washed out and reds lose accuracy.

7.0
Picture Quality
Vertical Viewing Angle
Color Washout From Below
32°
Color Washout From Above
32°
Color Shift From Below
36°
Color Shift From Above
35°
Brightness Loss From Below
33°
Brightness Loss From Above
33°
Black Level Raise From Below
70°
Black Level Raise From Above
70°
Gamma Shift From Below
37°
Gamma Shift From Above
39°

The Dell S2421H has decent vertical viewing angles. It's a bit worse than the horizontal viewing angle, but we don't expect this to be noticeable for most people.

8.6
Picture Quality
Gray Uniformity
50% Std. Dev.
3.554%
50% DSE
0.109%
5% Std. Dev.
0.394%
5% DSE
0.056%

The Dell S2421H has excellent gray uniformity. There's almost no noticeable dirty screen effect in the center, but the sides of the screen are a bit darker than the center. Near-dark scenes look much better, with almost no noticeable issues. Gray uniformity varies between individual units, but it's rarely an issue with recent monitors.

7.0
Picture Quality
Black Uniformity
Native Std. Dev.
1.345%
Std. Dev. w/ L.D.
N/A

The Dell S2421H monitor we bought has decent black uniformity, but this can vary between individual units. The entire screen has a bluish tint due to the low contrast ratio, but it's a bit patchy in spots. There's a bit of backlight bleed along the edges, but it's not too noticeable.

7.0
Picture Quality
Pre Calibration
Picture Mode
Standard
Luminance
275 cd/m²
Luminance Settings
100
Contrast Setting
75
RGB Controls
Default
Gamma Setting
No Gamma Setting
Color Temperature
7,347 K
White Balance dE
3.86
Color dE
2.98
Gamma
2.21

Out of the box, the Dell S2421H monitor we bought has just decent accuracy, but this can vary between individual units. Colors have good overall accuracy, but there are some noticeable issues, especially with highly-saturated colors. The white balance is mediocre, and most shades of gray are noticeably off. Gamma doesn't follow the sRGB target curve at all but is closer to a flat 2.2, so dark scenes are a bit too bright, and bright scenes are too dark. Finally, the color temperature is very cool, giving everything a bluish tint.

9.6
Picture Quality
Post Calibration
Picture Mode
Custom Color
Luminance
100 cd/m²
Luminance Settings
29
Contrast Setting
75
RGB Controls
99-100-93
Gamma Setting
No Gamma Setting
Color Temperature
6,428 K
White Balance dE
0.60
Color dE
0.60
Gamma
2.18

After calibration, the Dell S2421H has fantastic accuracy. Some colors are still a bit off, but everything else looks great, and no noticeable issues remain. Gamma is extremely close to the sRGB target curve, but bright scenes are a bit too dark. This is very common, though.

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.

8.5
Picture Quality
SDR Color Gamut
sRGB xy
95.9%
Adobe RGB xy
73.9%
sRGB Picture Mode
Custom Color
Adobe RGB Picture Mode
Custom Color

The Dell S2421H has an excellent SDR color gamut. It can display most of the sRGB target space used by the majority of desktop and web content. Sadly, it can't display colors wider than the sRGB primaries in the Adobe RGB color space.

8.6
Picture Quality
SDR Color Volume
sRGB In ICtCp
94.4%
Adobe RGB In ICtCp
77.9%
sRGB Picture Mode
Custom Color
Adobe RGB Picture Mode
Custom Color

This monitor has excellent SDR color volume. It can't display dark saturated colors very well due to the low contrast ratio, but other than that, it has no issues displaying colors at different brightness levels.

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

Unfortunately, this monitor can't display an HDR color gamut.

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

Unfortunately, this monitor can't display an HDR color gamut.

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 on our unit, but this can vary between individual units.

7.9
Picture Quality
Gradient
Color Depth
8 Bit

The Dell S2421H has good gradient handling. Since this monitor can only accept an 8-bit signal, there's noticeable 8-bit banding in our gradient test image. This isn't noticeable with regular 8-bit content.

10
Picture Quality
Color Bleed
Pixel Row Error
0.003%
Pixel Column Error
0.001%

There's no noticeable color bleed on our unit. This can vary between units, but it's rarely noticeable, even on displays that perform poorly on this test.

7.8
Picture Quality
Reflections
Screen Finish
Matte
Total Reflections
5.1%
Indirect Reflections
3.8%
Calculated Direct Reflections
1.4%

The Dell S2421H monitor has very good reflection handling. The matte anti-reflective coating does a good job reducing the intensity of direct lights, but it adds a bit of haze to the screen, which can be seen in our text clarity photo.

7.0
Picture Quality
Text Clarity
Sub-Pixel Layout
RGB

Due to the relatively low pixel density of this monitor, it has just decent text clarity. Running the ClearType wizard improves the appearance of diagonal lines (top photo), but there are some noticeable issues in apps that don't support ClearType.

Motion
7.6
Motion
Response Time @ Max Refresh Rate
Best Overdrive Setting
Normal
Rise / Fall Time
7.5 ms
Total Response Time
16.7 ms
Overshoot Error
3.0%
Dark Rise / Fall Time
8.7 ms
Dark Total Response Time
18.8 ms
Dark Overshoot Error
2.0%

Response Time SettingResponse Time ChartResponse Time TablesMotion Blur Photo
NormalChartTablePhoto
FastChartTablePhoto
ExtremeChartTablePhoto

The Dell S2421H has a good response time at the max refresh rate, but there's some noticeable blur behind fast-moving objects. Like most monitors, you can adjust the level of pixel overdrive. On this monitor, we recommend the 'Normal' Response Time setting, as it delivers the best results overall. There's some noticeable overshoot in a few transitions, but overall, it looks good. The 'Fast' setting has a much faster rise/fall time, but there's terrible overshoot in most transitions. Strangely, the 'Extreme' setting is a bit better overall than 'Fast'.

6.8
Motion
Response Time @ 60Hz
Best Overdrive Setting
Normal
Rise / Fall Time
7.2 ms
Total Response Time
20.9 ms
Overshoot Error
6.6%
Dark Rise / Fall Time
8.1 ms
Dark Total Response Time
21.9 ms
Dark Overshoot Error
7.4%

Response Time SettingResponse Time ChartResponse Time TablesMotion Blur Photo
NormalChartTablePhoto
FastChartTablePhoto
ExtremeChartTablePhoto

The response time is just okay at 60Hz, and it's worse than at the max refresh rate. With the same 'Normal' Response Time setting as the max refresh rate, there's more noticeable overshoot in most transitions, and the total response time is a bit slower. Again, the 'Fast' and 'Extreme' settings have terrible overshoot, but 'Extreme' is a bit better than 'Fast'.

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

Like most Dell monitors, the backlight is completely flicker-free at all backlight levels.

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 an optional backlight strobing feature, commonly known as black frame insertion (BFI).

7.8
Motion
Refresh Rate
Native
75 Hz
Max Refresh Rate
75 Hz
Variable Refresh Rate
Yes
FreeSync
Yes
G-SYNC
No
VRR Maximum
75 Hz
VRR Minimum
48 Hz
VRR Supported Connectors HDMI

The Dell S2421H has a limited 75Hz refresh rate. It supports FreeSync variable refresh rate technology (VRR), which helps reduce screen tearing. Unfortunately, the VRR feature doesn't work with NVIDIA graphics cards.

Inputs
9.1
Inputs
Input Lag
Native Resolution
7.4 ms
Native Resolution @ 60Hz
8.9 ms
Variable Refresh Rate
7.4 ms
Variable Refresh Rate @ 60Hz
9.2 ms
10 Bit HDR
N/A
Black Frame Insertion (BFI)
N/A

The Dell S2421H monitor has superb low input lag for a responsive gaming experience. Enabling the variable refresh rate feature causes the input lag to increase a bit at 60Hz, but it's still very responsive.

7.1
Inputs
Resolution And Size
Native Resolution 1920 x 1080
Aspect Ratio 16:9
Megapixels 2.1 MP
Pixel Density
93 PPI
Screen Diagonal 23.8"
Screen Area 241 in²

The 24 inch, 1080p screen is okay for basic office use, but it doesn't deliver a great amount of screen real estate for multitasking.

Inputs
Inputs
Inputs
Total Inputs
DisplayPort No
Mini DisplayPort No
HDMI 2 (HDMI 1.4)
DVI No
VGA No
DisplayPort Out No
USB No
USB C No
Analog Audio Out 3.5mm 1
Microphone In 3.5mm No
Digital Optical Audio Out No
Analog Audio Out RCA No
Power Supply Internal
Features
Features
Additional Features
RGB Illumination
No
Speakers
Yes
HDR10 No
Multiple Input Display
No

Unfortunately, this monitor has almost no extra features. There are built-in speakers, but like most monitors, they're not very good.

Features
On-Screen Display (OSD)
Features
Controls

Unfortunately, this monitor doesn't use a five-way joystick to navigate the on-screen display. There are four buttons under the bottom bezel to navigate the menus. It's not the most intuitive system, but there are so few options on this monitor that it's unlikely you'd need to adjust the settings often.

Features
In The Box

  • Power cord
  • HDMI cable
  • User guide

Differences Between Sizes And Variants

We tested the 24 inch Dell S2421H. There are two other variants: the Dell S2421HN, which has no speakers, and the Dell S2421HS, which has better ergonomics. We expect most of our results to be valid for those variants as well. All three variants are also available in a 27 inch size. The larger models have the same posted specifications as the 24 inch models, but we don't know how they perform.

Model Size Speakers Ergonomics
S2421H 24" Yes Tilt
S2421HN 24" No Tilt
S2421HS 24" Yes Height, pivot (rotation), swivel, tilt
S2721H 27" Yes Tilt;
S2721HN 27" No Tilt
S2721HS 27" Yes Height, pivot (rotation), swivel, tilt

If someone comes across a different type of panel or if their Dell S2421H doesn't correspond to our review, let us know, and we'll update the review. Note that some tests, such as gray uniformity, may vary between individual units.

Our unit of the Dell S2421H was manufactured in August 2021; you can see the label here.

Compared To Other Monitors

The Dell S2421H is a very basic model budget monitor. It delivers okay performance overall, but it doesn't stand out in any way. If you're willing to spend a bit more, there are much better budget models with higher resolution screens and better motion handling, but if you're on a budget, this monitor isn't terrible, either.

Also see our recommendations for the best monitors under $200, the best 1080p monitors, and the best gaming monitors.

Gigabyte M27Q

The Gigabyte M27Q is much better than the Dell S2421H. The Gigabyte has a larger, higher-resolution screen, with a faster refresh rate, much faster response time, and better ergonomics. The Gigabyte has lower input lag, better viewing angles, and it supports HDR.

AOC 24G2

The AOC 24G2 is much better than the Dell S2421H. The AOC is much better for every use, but it's especially better for gaming. The AOC has a faster refresh rate, and a significantly faster response time, resulting in clearer motion with less blur behind fast-moving objects. The AOC also has much better ergonomics, so it's easier to place it in an ideal viewing position.

HP X24ih

The HP X24ih is much better than the Dell S2421H. The HP has better viewing angles, a faster refresh rate, and a significantly faster response time, resulting in much clearer motion. The HP also has better ergonomics, so it's easier to place it in an ideal viewing position.

Samsung Odyssey G3 LF27G35T

The Samsung Odyssey G3 LF27G35T is much better than the Dell S2421H, but it uses a different panel type. The Samsung has a VA panel, which delivers much better contrast for dark-room viewing. The Samsung also has much better ergonomics and a faster refresh rate. On the other hand, the Dell has better viewing angles and a faster response time, despite the faster refresh rate on the Samsung.

Dell S2419HGF

The Dell S2419HGF is better than the Dell S2421H, but they use different panel types, each with strengths and weaknesses. The S2419HGF uses a TN panel with a faster refresh rate and a significantly faster response time. The S2419HGF also has a much better stand, with much better ergonomics. On the other hand, the S2421H has better viewing angles and much better gray uniformity.

BenQ EX2780Q

The BenQ EX2780Q is much better than the Dell S2421H. The BenQ has a larger, higher-resolution screen, better viewing angles, and supports HDR. The BenQ also has a faster refresh rate, and a much faster response time, resulting in clearer motion with less blur behind fast-moving objects.

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