The range of Karcher pressure washers can be a little confusing making it difficult to decide which model is the best for your needs. Two very similar and popular pressure washers are the K3 and K4.
In this article, I’ll be directly comparing these two Karcher pressure washers in terms of their performance and key features so you can decide which is the best option.
Karcher K3 vs K4
The Karcher K4 is more powerful and expensive than the Karcher K3. The K4 has a maximum flow rate of 420 L/hour and 130 bar pressure whereas the K3 has a maximum flow rate of 380 L/hour and 120 bar pressure. The K4 is also heavier and larger than the K3.
| Feature | Karcher K3 | Karcher K4 |
| Max Flow Rate | 380 L/ hour | 420 L/ hour |
| Max Pressure | 120 bar | 130 bar |
| Area Performance | 25 m2/ hour | 30 m2/ hour |
| Power Rating | 1600 W | 1800 W |
| Hose Length | Compact version is 6 meters, Power Control version is 7 meters | Compact version is 6 meters, Power Control version is 8 meters |
| Compact Version Weight | 4.2 kg | 4.7 kg |
| Power Control Version Weight | 4.4 kg | 11.5 kg |
| Motor | Air-Cooled on all versions | Air-Cooled on Compact version, Water-Cooled on Power Control version |
Still considering other Karcher models? Make sure you check out my guide to the Karcher pressure washer range to make sure you’re choosing the best option for your requirements.
Performance
There are two aspects to consider here:
- Pressure
- Flow rate
The Karcher K4 is a more expensive model compared to the K3 and hence offers an improvement in performance due to its greater maximum pressure and flow rate.
- Karcher K3 models have a maximum flow rate of 380 L/ hour whereas K4 models have a maximum flow rate of 420 L/ hour.
- Karcher K3 model s have a 120 bar maximum pressure whereas K4 models have a 130 bar maximum pressure.
Hence, the K4 offers an 11% increase in flow rate and an 8% maximum pressure increase.
Both models are capable of cleaning cars, outdoor furniture and patio flags though and the pressure difference isn’t huge in reality.
If you are washing your car and using a snow foam cannon, you’ll find that the K4 helps to create thicker snow foam. Although, you’ll still be able to get very good snow foam from a K3 if you pair it with a good quality foam cannon.
Size and Weight
There are several versions of both the K3 and K4 pressure washer. The K3 has 3 variants: compact, home and power control. The K4 has 2 variants: compact and power control.
The K4 versions are heavier and larger than the K3 versions. The “compact” variants are of course smaller and lighter to help save space when storing.
Here are some tables to show the different dimensions and weights of each pressure washer.
Metric Units
| Karcher Model | Length | Width | Height | Weight |
| K3 Compact | 26.4 cm | 25.6 cm | 45.0 cm | 4.2 kg |
| K3 Home | 27.5 cm | 27.9 cm | 80.2 cm | 6.5 kg |
| K3 Power Control | 29.7 cm | 29.0 cm | 67.7 cm | 4.4 kg |
| K4 Compact | 27.3 cm | 25.6 cm | 45.7 cm | 4.7 kg |
| K4 Power Control | 40.2 cm | 30.6 cm | 58.8 cm | 11.5 kg |
Imperial Units
| Karcher Model | Length | Width | Height | Weight |
| K3 Compact | 10.4″ | 10.1″ | 17.7″ | 9.3 lbs |
| K3 Home | 10.8″ | 11.0″ | 31.6″ | 14.3 lbs |
| K3 Power Control | 11.7″ | 11.4″ | 26.7″ | 9.7 lbs |
| K4 Compact | 10.7” | 10.1” | 18.0” | 10.4 lbs |
| K4 Power Control | 15.8” | 12.0” | 23.1” | 25.4 lbs |
Other Key Differences
There are also a few other differences between the K3 and K4 worth mentioning:
- The K3 Compact, K3 Home and K4 Compact all have 6 meter hoses. The K3 Power Control has a 7 meter hose and the K4 Power Control has an 8 meter hose.
- All K3 models and the K4 Compact have air-cooled motors. The K4 Power Control has a water-cooled motor which is designed to be more durable.
- The K4 has a higher power rating of 1800W compared to the K3 which has a rating of 1600W so the K4 will use slightly more electricity.
Model Variants (Power Control, Compact, Home etc.)
There are several different versions of both the K3 and K4 pressure washer. Karcher use the “K-number” to group models the series according to the flow rate, pressure and power rating. However the different variants are separated according to the accessories and some specification differences.
K3 Variants
- K3 Compact
- K3 Home
- K3 Compact Home
- K3 Power Control
- K3 Premium Power Control
All these models have the same power rating, maximum pressure rating, flow rate and an air-cooled motor. Here is a table highlighting the differences between them.
| Feature | K3 Compact | K3 Compact Home | K3 Home | K3 Power Control | K3 Premium Power Control |
| Hose Length | 6 meters | 6 meters | 6 meters | 7 meters | 7 meters |
| Weight (without accessories) | 4.2 kg | 4.2 kg | 6.5 kg | 4.4 kg | 5.6 kg |
| Dimensions (L x W x H) | 26.4 x 25.6 x 45.0 cm | 26.4 x 25.6 x 45.0 cm | 27.5 x 27.9 x 80.2 cm | 29.7 x 28.0 x 67.7 cm | 34.0 x 28.1 x 67.7 cm |
| Detergent Application | Suction | Suction | Tank | Tank | Tank |
| Telescopic Handle | Yes | Yes | No | Yes | Yes |
| Integrated Hose Reel | No | No | No | No | Yes |
| LED Trigger Display | No | No | No | Yes | Yes |
| Accessories Included | Vario Lance Dirt Blaster | Vario Lance Dirt Blaster Patio Cleaner | Vario Lance Dirt Blaster Patio Cleaner | Vario Lance Dirt Blaster | Vario Lance Dirt Blaster Patio Cleaner |
K4 Variants
- K4 Compact
- K4 Power Control
- K4 Power Control Home
- K4 Power Control Car & Home
- K4 Premium Power Control Car & Home
All K4 models have the same power and pressure ratings, and flow rates. Here is a table highlighting the differences between them.
| Feature | K4 Compact | K4 Power Control | K4 Power Control Home | K4 Power Control Car & Home | K4 Premium Power Control Car & Home |
| Hose Length | 6 meters | 8 meters | 8 meters | 8 meters | 8 meters |
| Weight (without accessories) | 4.7 kg | 11.5 kg | 11.5 kg | 11.5 kg | 12.0 kg |
| Dimensions (L x W x H) | 27.3 x 25.6 x 45.7 cm | 40.2 x 30.6 x 58.8 cm | 40.2 x 30.6 x 58.8 cm | 40.2 x 30.6 x 58.8 cm | 41.4 x 30.6 x 58.8 cm |
| Motor | Air-Cooled | Water-Cooled | Water-Cooled | Water-Cooled | Water-Cooled |
| Detergent Application | Suction | Plug and Clean System | Plug and Clean System | Plug and Clean System | Plug and Clean System |
| LED Display on Trigger | No | Yes | Yes | Yes | Yes |
| Integrated Hose Reel | No | Yes | Yes | Yes | Yes |
| Accessories Included | Vario Lance Dirt Blaster | Vario Lance Dirt Blaster | Vario Lance Dirt Blaster Patio Cleaner | Vario Lance Dirt Blaster Patio Cleaner Car Brush Foam Cannon Car Shampoo | Vario Lance Dirt Blaster Patio Cleaner Car Brush Foam Cannon Car Shampoo |
Accessory Kits
As you’ll have noticed from the tables above, some models come with a “home” or “car and home” kit which features some extra accessories.
Whilst the “home” accessories can be quite useful, I strongly advise against using the car accessories.
The “rotating wash brush” will scratch the paintwork on the car and should never be used. You can also find much better foam cannons from other companies which are compatible with the Karcher models as well as better shampoos.
Check out my car cleaning product recommendations if you’re looking for some suggestions.
K3 and K4 Similarities
- Two nozzles: the vario lance and dirt blaster lance.
- Quick connect on the machine for the hose.
- All models have a 5 meter main cable.
- The maximum water feed temperature is 40°C.
- The minimum pressure is 20 bar.
Full Specification List
| Feature | K3 Compact | K3 Home | K3 Power Control | K4 Compact | K4 Power Control |
| Current Type | 220-240 V | 220-240 V | 220-240 V | 230-240 V | 230-240 V |
| Minimum Pressure | 20 bar | 20 bar | 20 bar | 20 bar | 20 bar |
| Maximum Pressure | 120 bar | 120 bar | 120 bar | 130 bar | 130 bar |
| Max Flow Rate | 380 L/ hour | 380 L/ hour | 380 L/ hour | 420 L/ hour | 420 L/ hour |
| Area Performance | 25 m2/ hour | 25 m2/ hour | 25 m2/ hour | 30 m2/ hour | 30 m2/ hour |
| Water Feed Max Temp | 40°C | 40°C | 40°C | 40°C | 40°C |
| Power Rating | 1600 W | 1600 W | 1600 W | 1800 W | 1800 W |
| Power Cable Length | 5 meters | 5 meters | 5 meters | 5 meters | 5 meters |
| Hose Length | 6 meters | 6 meters | 7 meters | 6 meters | 8 meters |
| Weight (without accessories) | 4.2 kg | 6.5 kg | 4.4 kg | 4.7 kg | 11.5 kg |
| Dimensions (L x W x H) | 26.4 x 25.6 x 45.0 cm | 27.5 x 27.9 x 80.2 cm | 29.7 x 28.0 x 67.7 cm | 27.3 x 25.6 x 45.7 cm | 40.2 x 30.6 x 58.8 cm |
| Motor | Air-Cooled | Air-Cooled | Air-Cooled | Air-Cooled | Water Cooled |
| Detergent Application | Suction | Tank | Tank | Suction | Plug and Clean System |
| LED Display on Trigger | No | No | Yes | No | Yes |
| Telescopic Handle | Yes | No | Yes | Yes | Yes |
Still not sure which Karcher model to go for? Check out my complete guide to the Karcher Pressure Washer range for more information.
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