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.
We buy and test more than 30 monitors each year, with units that we buy completely on our own, without any cherry-picked units or samples. We put a lot into each unbiased, straight-to-the-point review, and there's a whole process from purchasing to publishing, involving multiple teams and people. We do more than just use the monitor for a week; we use specialized and custom tools to measure various aspects with objective data-based results. We also consider multiple factors before making any recommendations, including the monitor's cost, its performance against the competition, and whether or not it's easy to find.
Our Verdict
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.
- Image remains accurate at an angle.
- Superb low input lag.
- Very good reflection handling.
- Excellent gray uniformity.
- Terrible ergonomics.
- Mediocre contrast ratio.
- Small, low-resolution screen.
- No DisplayPort input.
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.
- Image remains accurate at an angle.
- Very good reflection handling.
- Excellent gray uniformity.
- Terrible ergonomics.
- Small, low-resolution screen.
- No DisplayPort input.
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.
- Superb low input lag.
- FreeSync support.
- Good response time at the max refresh rate.
- Terrible ergonomics.
- Mediocre contrast ratio.
- Small, low-resolution screen.
- No DisplayPort input.
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.
- Image remains accurate at an angle.
- Excellent SDR color gamut.
- Excellent gray uniformity.
- Terrible ergonomics.
- Mediocre contrast ratio.
- No HDR support.
- Small, low-resolution screen.
- No DisplayPort input.
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.
- Image remains accurate at an angle.
- Excellent SDR color gamut.
- Excellent gray uniformity.
- Terrible ergonomics.
- Mediocre contrast ratio.
- Small, low-resolution screen.
- No DisplayPort input.
This monitor doesn't support HDR.
Check Price
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.
Popular Monitor Comparisons
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.
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.
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.
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.
The Samsung Odyssey G3 F27G35T 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.
Test Results
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.
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.
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.
The back of the monitor is very plain. There's a hole in the stand for very basic cable management.
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.
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.
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.
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.
This monitor doesn't support HDR.
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.
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.
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.
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.
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.
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.
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.
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.
Unfortunately, this monitor can't display an HDR color gamut.
Unfortunately, this monitor can't display an HDR color gamut.
There are no signs of temporary image retention on our unit, but this can vary between individual units.
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.
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.
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.
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.
| Response Time Setting | Response Time Chart | Response Time Tables | Motion Blur Photo |
| Normal | Chart | Table | Photo |
| Fast | Chart | Table | Photo |
| Extreme | Chart | Table | Photo |
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'.
| Response Time Setting | Response Time Chart | Response Time Tables | Motion Blur Photo |
| Normal | Chart | Table | Photo |
| Fast | Chart | Table | Photo |
| Extreme | Chart | Table | Photo |
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'.
Like most Dell monitors, the backlight is completely flicker-free at all backlight levels.
This monitor doesn't have an optional backlight strobing feature, commonly known as black frame insertion (BFI).
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.
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.
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.
Unfortunately, this monitor has almost no extra features. There are built-in speakers, but like most monitors, they're not very good.
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.
