These three docks look like different products.
In reality, they are the same dock platform with two optional upgrades:
| Model | Video & Ports | Dell Charging | Remote IT Management |
|---|---|---|---|
| WD25 | Same as all | 100W | No |
| WD25Z | Same as all | 130W | No |
| SD25 | Same as all | 130W | Yes (built-in) |
These are USB-C docks with DisplayPort Alt Mode (not Thunderbolt). If you need Thunderbolt 4 features, see our WD22TB4 vs WD25TB4 vs SD25TB4 comparison.
If you only care about displays, ports, and bandwidth, they are identical.
You only pay extra for more Dell power or enterprise remote management.
What all three models have in common
WD25, WD25Z, and SD25 are built on the same hardware design.
That means the most important things — video output and I/O — are the same.
Display capability (identical on all three)
All models support DP1.4 and DP2.1 with Display Stream Compression.
| Mode | Max displays |
|---|---|
| Without DSC | 1 × 4K @ 60Hz |
| With DSC | 2 × 5K @ 60Hz |
| With DSC | 1 × 6K @ 60Hz |
| With DSC | 4 × 3440×1440 @ 60Hz |
No model gives you more screens or higher resolution than the others.
Video ports (identical)
All three docks include:
- 2 × DisplayPort 1.4
- 1 × HDMI 2.1
- 1 × USB-C DisplayPort (DP Alt Mode)
You can connect up to four monitors in the same ways on all models.
USB and networking (identical)
| Feature | All models |
|---|---|
| USB-A | 4 × USB-A 10Gbps |
| USB-C (data) | 1 × USB-C 10Gbps |
| USB-C (power) | 1 × 15W |
| Ethernet | 2.5GbE |
| Cable length | 0.9 m |
| Size | 205 × 90 × 35 mm |
No difference here.
No extra speed. No extra ports.
What is actually different
Now we get to the real differences.
They are only about power and management.
1) Charging power
| Model | Power Adapter | Dell Laptops | Non-Dell laptops |
|---|---|---|---|
| WD25 | 130W | 100W | 96W |
| WD25Z | 180W | 130W | 96W |
| SD25 | 180W | 130W | 96W |
Only Dell business laptops can use 130W.
Non-Dell brands will always get 96W, no matter which model you buy.
2) Remote management
This is where SD25 is different.
| Feature | WD25 / WD25Z | SD25 |
|---|---|---|
| Cloud management without a PC | No | Yes |
| Zero-touch enterprise setup | No | Yes |
| Remote firmware updates | No | Yes |
| Remote port disable / lock | No | Yes |
| Works when laptop is unplugged | No | Yes |
SD25 has its own built-in management computer.
WD25 and WD25Z do not.
For normal users, this brings no benefit at all.
What this means in real life
Let’s talk about real buyers.
Surface, Lenovo, HP and other Non-Dell users
You get:
- The same displays
- The same ports
- The same bandwidth
- The same 96W charging
WD25Z and SD25 give you nothing extra.
Tip: Want to understand USB-C power delivery and why non-Dell laptops are limited to 96W? See our cross-brand compatibility guide.
Dell Latitude or Precision with high power needs
If your Dell laptop needs more than 100W, WD25 will limit performance.
WD25Z gives you the full 130W.
Not sure which dock fits your Dell laptop? Use DockSelector. Input your laptop model and we'll give you the compatible docks.
Large enterprise with IT management
Only if you need:
- Remote locking
- Cloud-controlled firmware
- Zero-touch provisioning
- Inventory tracking
If you don’t run an IT department, SD25 is just expensive WD25Z.
Final verdict
All three docks are the same where it matters:
screens, ports, and bandwidth.
You only pay more for:
- More Dell charging (WD25Z)
- Enterprise remote management (SD25)
For most people, WD25 is the smartest buy.
Need help choosing? For a complete guide to all Dell docking stations including Thunderbolt 4 options, see our comprehensive Dell dock buying guide.