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Karcher Window Vac:

The Complete Buyer’s Guide

image showing the karcher window vac in use

image showing the karcher window vac being used to remove condensation

Does anyone actually enjoy cleaning windows?

We certainly don’t.

Not only is it time-consuming, but unless you put in the time and effort to get it right, you end up with a subpar (i.e., streaky) finish.

It isn’t for lack of trying either.

From fancy squeegees that overpromise and underdeliver, to old-school methods involving vinegar and newspaper – we’ve tried it all.

It’s not even the amount of elbow grease that’s needed to clean the window in the first place that frustrates us most – it’s all the work afterword trying to rid the glass of every last streak.

Thankfully, there is an easier option.

Enter the Window Vac, a handy tool which Karcher claims can cut the time required to clean windows to almost a third.

Sound too good to be true? Well, it isn’t, at least not if the countless positive reviews posted online or the 15+ million satisfied Window Vac customers worldwide is anything to go by.

But is it all just savvy marketing, or is the Window Vac really as good as Karcher would have you believe?

We’re on a mission to find out.

Let’s get stuck in to reveal everything you need to know about the Karcher Window Vac – the good, the bad, and the ugly…

Who It’s Aimed At

It’s best-suited to the average homeowner looking for a quicker and easier way to clean and dry and their home or car windows, or to dry surfaces such as tiles, shower screens, mirrors, and countertops.

Is it likely to be of interest to commercial window cleaners? We don’t think so, and we’d probably advise against it altogether for heavy-duty usage as the battery life won’t be sufficient.

Casual users shouldn’t be put off by this caveat, though.

With a battery life of 20-minutes available from even the base model (for cleaning approximately 18 standard-sized windows), all the way up to 35-minutes from the top-specced WV5 model (which equates to around 35 windows), there’s more than enough battery life available to suit even the most demanding of homeowners.

What It Can Be Used For

The Karcher Window Vac is designed for use on smooth, moist surfaces.

It’s ideal for tackling tasks such as removing the dirty water that remains after cleaning glazing to leave a streak-free finish, removing condensation from your bathroom that would otherwise lead to limescale build-up, and for sucking up any small spillages that would otherwise require mopping or paper towels.

Here are some specific examples of things you can use it on:

  • Interior/exterior glazing
  • Mirrors
  • Tiles
  • Shower screens
  • Oven door glass
  • Car windows
  • Worktops

And here’s what should be avoided…

  • Vacuuming up dust or dirt.
  • Cleaning up larger spills (anything above 25 ml) on worktops or floors.
  • Using the Window Vac with spirit-based or foam-type window cleaners (use it with conventional window cleaning fluids only).

What It Comes With

Karcher understands that one size does not fit all, and so they offer several different Window Vac kits to suit a variety of different users’ needs and budgets.

Here is what each kit comes with (scroll table if needed):

Kit Type
Example Kit
Kit Contents


Standard kits come with:

  • 1x window vacuum (with non-removable lithium-ion battery)
  • 1x battery charger


Plus kits come with:

  • 1x window vacuum (with non-removable lithium-ion battery)
  • 1x battery charger
  • 1x standard spray bottle with microfibre wiping cloth
  • 1x glass cleaner concentrate sachet (20 ml)


Plus kits come with:

  • 1x window vacuum (with removable lithium-ion battery)
  • 1x extra narrow suction nozzle
  • 1x battery charger
  • 1x standard spray bottle with microfibre wiping cloth
  • 1x glass cleaner concentrate sachet (20 ml)


Anniversary kits come with:

  • 1x window vacuum (with non-removable lithium-ion battery)
  • 1x extra narrow suction nozzle
  • 1x battery charger
  • 1x standard spray bottle with microfibre wiping cloth
  • 1x glass cleaner concentrate sachet (20 ml)

Ease of Use

One of the standout benefits of the Karcher Window Vac is just how easy it is to use.

It’s quite similar to how you’d approach using a cordless vacuum (although to clarify, you should never use the window vac to suck up dirt or dust) – there are no settings to fiddle with and no complicated startup procedures; simply switch it on, and you’re good to go.

When it comes to the cleaning process itself, the simplicity continues.

You see, regardless of which model you choose, all it takes is a simple three-step process to go from dirty to clean windows in around a third of the time it takes with traditional window cleaning methods.

Before outlining the process, something worth clarifying is that the Karcher unit itself doesn’t perform the cleaning, but rather, it forms the third and final step of vacuuming up any water left over after the cleaning process.

Now that’s out of the way, here are the three easy steps for cleaning windows:


Spray the window with a mix of detergent and water.


Wipe the surface clean using a microfiber cloth.


Finally, vacuum up the dirty water with the Window Vac to leave the surface dry.

That’s it; there’s nothing else to it.

One thing to bear in mind though is that if you opt for a Standard package, you won’t receive the spray bottle kit or the microfiber cleaning cloth shown above, so you’ll need to purchase these separately or use your own if you already have them.

For cleaning surfaces other than windows, the process is just as simple (and in some cases, even more so!).

For example, cleaning mirrors would follow the same three-step process shown above, while drying off shower screens or tiles to prevent limescale, or cleaning up a spill from a dog’s bowl, for example, would only require the third step only to dry off any moisture.

When you’ve finished using the Window Vac, Karcher has made the process of leaving it ready for the next cleaning task incredibly simple too.

Firstly, it only takes a few seconds to empty the dirty water tank, which you do by popping open the cap as shown in the image above to allow emptying into the nearest sink, for example.

The recharging process is the same regardless if you choose the WV5 with a removable battery or any of the other models with a fixed one. The charging adaptor supplied with each kit connects directly into the body of the vacuum, with the other end connected to a power outlet to begin charging.

When it comes to swapping out the suction nozzle, either on a particular job or ahead of your next cleaning task, these can be quickly clicked in or out to best-suit your needs with minimal fuss or hassle.

Even better? You can also swap out the Window Vac’s blades (see above photo) to extend its life and cleaning performance once the originals start to wear-out. No engineering degree needed, we promise.

Ergonomic Design

If there’s one feature that we appreciate most in any handheld cleaning tool (especially one that we’ll likely end up using for 20+ minutes like the Karcher Window Vac, it’s a well-thought-out, smart design that blends ergonomics to reduce the strain of using it.

Probably the most striking aspect in this regard in how light each model is versus their size (even with the dirty water tank being full), something which you’re sure to appreciate on longer cleaning tasks or those that require constant reaching towards the top of taller windows.

We’ve found that the vacuum is best-suited to vertical use (i.e., being used in an up and down motion), all thanks to the large handle which makes it easier to hold and which also helps maximize grip during use.

The Window Vac can also just as easily be used horizontally in a side-to-side motion too, although, if we’re entirely honest, this does feel a little bit more cumbersome given the size of the unit, and it can feel slightly unbalanced at times in this orientation, but overall, it’s still very manageable.

Accessories Available

From extension poles that help you clean hard-to-reach places to narrow suction heads that let you clean even the smallest of windows with ease, Karcher has a small but incredibly useful range of accessories available that fit or work with every Window Vac model.

Several of these accessories are available as part of the Plus, Premium, or Anniversary kit types listed above, and you’ll usually get a saving overall when buying them as part of a bundle.

You can, of course, purchase these separately too if you’ve opted for a Standard kit.

Here are some of the most popular options:

What’s It Really like to Live With?

As we’ve mentioned, the Karcher Window Vac is well-suited to tackling a range of moisture-sucking requirements, from cleaning off water and detergent from windows following cleaning, to vacuuming up condensation from bathroom tiles and mirrors after you’ve taken a shower.

It certainly sounds great, but what’s it like actually to live with?

What are the various quirks and issues that don’t come across in Karcher’s polished promotional material and product demonstrations?

Well, unfortunately, there are a few…

General Observations:

The first couple of points are by no means major, but we think that they’re worth mentioning anyway.

For starters, there’s the dirty water tank capacity, and at 100ml, it’s probably just the right size for small to medium-sized jobs. You’ll need to empty the water tank periodically on larger jobs which could become a hassle, but thankfully, as we’ve mentioned above, this is very easy to do.

The next limitation comes from the microfiber cloth you use to clean the window before using the Window Vac. Regardless if you opt for Karcher’s spray bottle and microfiber combo, or use your own, you’ll likely need to give this a good wash or swap it out mid-job to achieve the best possible finish.

You see, the Window Vac relies on a thoroughly clean surface, and so, any dirt that remains will get pulled along by the vacuum’s squeegee causing streaks, so it’s crucial to spend time getting the surface completely clean before using the vacuum.

To be honest, the previous point isn’t a criticism so much as an observation, as this would happen regardless of what type of squeegee you were using.

cleaning windows prior to using karcher wv2 model

Working Near Window Sills:

You’ll discover the next quirk when trying to use your Karcher vac near a window sill or other horizontal surface.

Given the unit’s size and shape, it usually isn’t possible to continue using it in a vertical orientation, as the base of the unit collides with the window sill preventing it from going any further.

(You can’t angle the base outwards either, as this causes suction to be lost limiting how much water gets removed from the surface).

One option is to tilt the unit sideways to use it horizontally, and while this sounds easy enough in theory, it leaves a greater chance of ending up with streaking or for small amounts of water to leak from the Window Vac.

Is this a deal breaker? Probably not, as you can still end up with a satisfactory finish this way, and it’s a technique that gets easier with practice.

image showing the karcher window cleaner being used near the bottom of a window

The Need for Detergent:

Speaking of finish, it’s worth mentioning that the best finish comes from using a dedicated cleaning detergent ahead of using the Window Vac.

Yes, you could opt for just using water, but this will end up leaving more dirt on the windows, and so the Window Vac’s squeegee will pull this along causing streaking.

A number of the kits come with a small sachet of cleaning detergent, although, this is pretty much just a trial quantity and so it won’t last long.

We recommend buying an extra bottle of Karcher’s cleaning detergent when purchasing your Window Vac, as it’s tried and tested and isn’t particularly expensive.


Finally, there’s the overall battery life to consider.

Despite the benefits of the lithium-ion battery featured in each model being undeniable (for example, longer life and smaller overall size versus other battery types), it’s worth bearing in mind that there is a vast difference in available battery life (as much as 40%!) depending on which Window Vac model you choose.

At the bottom of the scale is the WV1 which is capable of approximately 20-minutes of vacuuming (equal to about 18 standard-sized windows), with the range-topping WV5 being capable of 35-minutes (or around 35 standard-sized windows).

Yes, the batteries are rechargeable, but on the WV1, WV2, and the 10th Anniversary models, they’re non-removable. As such, you’ll need to wait anywhere between 2 to 3+ hours before you can reuse the vac, which may be a touch inconvenient if you want to tackle your windows and bathroom in one charge, for example.

The WV5 model, however, does feature a removable battery, and an extra one can be purchased relatively cheaply, so this is the model we’d recommend if you’re looking to tackle longer/more extensive cleaning requirements regularly.

replacing the battery on the Karcher WV5 window cleanerreplacing the battery on the Karcher WV5 window cleaner

So, what’s the bottom line on the above ‘issues’?

Do they make the Window Vac more of a pain than a pleasure to live with?

No – as despite these there’s no denying that using the Karcher Window Vac is vastly quicker and easier than conventional window cleaning processes, plus, as we’ve shown, you can overcome each of these quirks relatively easily.

In Summary

There are countless things that we love about the Karcher Window Vac.

From the fact that it speeds up the mundane task of cleaning windows (by up to 300%!) while making it easier to get that all-important streak-free finish, to its ability to just as quickly tackle other tasks such as drying up condensation or cleaning up spills – it’s a true all-rounder.

You can rest assured that you won’t just be investing in the latest gimmick either by purchasing a Window Vac.

Karcher, perhaps better known for pressure washers, pioneered the window vacuum concept over a decade ago. With several revisions since, as well as over 15+ million satisfied customers to-date, you can be sure that you’re buying into something that has been genuinely tried, tested, and approved.

Nothing is perfect, however, and the Window Vac is no different with there being two main drawbacks in our opinion.

The first is the price, and while none of the models are extortionate by any means, each is considerably more expensive than a conventional microfiber cloth and squeegee.

Is the price justified?

We think so, as despite costing more, we still view each model as providing considerable value for money.

You see, the fact remains, most people hate cleaning windows, and so any gadget which a) works, and b) speeds up the process is an easy recommendation in our eyes.

When coming to your own conclusion though, you’ve got to think about how much you value your time – because that’s what the Window Vac offers in spades – more time spent away from cleaning windows and whatever other surfaces you end up using it on.

The second drawback is the battery life which we alluded to above, although this will probably only be an issue for anyone looking to tackle a top-to-bottom clean in a larger home.

So, do either of these issues tip the scales in favor of us recommending you look elsewhere for your window cleaning needs?

Hardly – we still think that adding one to your cleaning collection is a no-brainer, especially, if like us, you value your time and would do anything in your power to reduce the hassle of cleaning windows, all the while improving the end finish.

Click Here for Pricing, Reviews, & More Images of the
Karcher Window Vac

Karcher Window Vac – The Pros
  • There is a variety of different model types available to suit almost all budgets/needs.
  • It’s highly flexible in that you can use it to vacuum up moisture from vertical surfaces such as windows and mirrors, as well as on horizontal surfaces like countertops.
  • It’s significantly quicker to use than conventional window cleaning methods (up to three times quicker, in fact, according to Karcher).
  • With several revisions across its 10+ year lifespan, as well as over 15-million satisfied customers to-date, it’s genuinely tried, tested, and approved.
  • There are zero settings to fiddle with and no complicated start-up procedures to worry about. Simply switch it on, and you’re good to go.
  • It’s very clean to use all thanks to the powerful vacuum function which removes much of the annoying dripping or run-off that occurs with a conventional squeegee.
  • It’s quick and easy to remove dirty water once the built-in tank is full.
  • Each model features a removable suction nozzle that you can swap out in seconds depending on your needs.
  • The lithium-ion battery featured in each model helps to maximize usage time between charges.
  • The ergonomic design of the Window Vac means that it’s both lightweight and easy to hold.
  • There are a variety of different accessories and spares available, for example, a narrower suction head and extension pole, as well as new microfiber cloths for the spray bottle kit and new squeegee blades.
  • Every model in Karcher’s Window Vac range comes with a two-year warranty.
Karcher Window Vac – The Cons
  • It can leave streaks if the surface you’re vacuuming is not entirely clean beforehand.
  • It can be challenging to use around the bottom of windows near window sills or other horizontal obstructions. This usually requires vacuuming sideways which can lead to small amounts of water leakage or streaking.
  • Battery life may be an issue for some users on the cheaper models.
  • Only the WV5’s battery can be swapped out to extend usage time – all other models require a long charge time of either two or three-plus hours before reuse.
  • The best results are achieved when using the Window Vac with a proper window cleaning detergent, which adds to the cost of each use.

Popular Comparison

Karcher Window Vac WV1 vs WV2 vs WV5

There are four main Window Vac models available, ranging from the WV1 to the WV5 (in addition to the WV Anniversary edition).

The main thing to consider when choosing a model is the battery life you’ll need, with the general rule of thumb being that the higher up the range you go, the greater the battery life per charge but the more you’ll pay.

Thankfully, it’s relatively easy to work out how much battery life you’ll need using the ‘Cleaning Performance per Charge’ info provided in the table below, as this shows the typical number of windows you’ll be able to complete with each charge.

As shown, the WV1 comes with the shortest possible battery life of around 20-minutes given that it’s the base model (and it’s also the cheapest), which provides enough power to clean around 18 standard-sized windows.

The range-topping WV5, on the other hand, has about 40% more runtime than the WV2, and it’s also the only model that lets you remove the battery.

Because of this, you can purchase an additional battery for the WV5 to bypass the need to wait for either 120-minutes or 185-minutes to continue cleaning like you need to do with the lower-specced models.

As mentioned above, there is also a fourth model above – the Karcher 10th WV Anniversary Edition – which we haven’t featured in the table below as it’s essentially the same as the WV5 model, bar a non-removable battery and a slightly different color scheme.

Here are the various details for each of the three main models:

(Scroll table if needed)


image of the karcher wv1 window cleaner
image of the Karcher window vac WV2
image of the Karcher window vac WV5

Model Number:








Product Type:

Window Vacuum Cleaner

Window Vacuum Cleaner

Window Vacuum Cleaner

Powered By:

Lithium-Ion Battery

Lithium-Ion Battery

Lithium-Ion Battery

Typical Battery Life:

20 minutes

25 minutes

35 minutes

Cleaning Performance per Charge:

Approx. 55m² (18 windows)

Approx. 75m² (25 windows)

Approx. 105m² (35 windows)

Typical Battery Charging Time:

185 minutes

120 minutes

185 minutes

Removable Battery:




Dirty Water Capacity:

100 ml

100 ml

100 ml

Cleaning Width:



280mm / 170mm

Dimensions (L,W,H):

5.12″ x 9.84″ x 10.83″

4.72″ x 11.02″ x 12.60″

4.92″ x 11.02″ x 12.80″

Product Weight (inc. battery):

1.1 lbs

1.5 lbs

1.5 lbs


Frequently Asked Questions
  1. What is the latest model of Karcher Window Vac?
The latest model (correct as of the time of writing) is the Karcher 10-year WV Anniversary Edition, which is essentially the same as the WV5 model (minus the removable battery) but available in a special colorway to celebrate the 10th anniversary of Karcher’s Window Vac series.
  1. Which Karcher Window Vac model should I buy?
It depends what you’re looking for specifically.

If getting value for money is your top priority, then the WV1 lets you enjoy the benefits of the Karcher Window Vac’s cleaning capabilities for the lowest possible price.

If you have a lot of window or surfaces to clean, however, the WV1 probably won’t cut it, as its battery only lasts about 20-minutes compared to the 25 and 35-minutes in the WV2 and WV3 models respectively.

Does the increase in runtime justify the extra price for these models? We think so.

You see, for us, battery life is a top priority, especially considering the relatively long charge time (around 2 or even 3+ hours depending on model), so we’d want to get as much cleaning done per charge.

You can check out our comparison of each of the various models here to help you decide which is best for you.

  1. What detergent can I use in my Karcher Window Vac?
Karcher offers a specific Glass Cleaner Concentrate for use with the Window Vac tool.

You don’t use this window the vacuum itself, but rather, you can add it to to the spray bottle that comes with several of the different kits (or that is available separately here) in a mix of around one and a half capfuls to the rest clean water.

The detergent can also be used manually with cloths, sponges or rubber squeegees to provide a streak-free finish as well as a pleasant aroma that won’t damage delicate surfaces.

  1. How do you use the Karcher window cleaner?
There are three main steps to using the Karcher window cleaner:

  1. Spray the surface with a water/detergent mix.
  2. Wipe the surface using a microfibre cloth.
  3. Finally, vacuum up the dirty water using the window vac to leave the surface both clean and dry.

Check out this YouTube video to see these particular steps in more detail.

  1. Can you purchase replacement blades and/or a smaller cleaning head?

You can buy replacement blades and a narrow suction head to increase both your window vacuum’s life and cleaning flexibility.

  1. Can the batteries be changed on any of the Karcher window cleaner models?
You can only remove the battery from the WV5 model.

The WV1, WV2, and the Karcher ’10th anniversary Window Vacuum’ all feature non-removable batteries.

  1. How long does the charge last?
The typical battery life for each model is as follows:

  • WV1: 20 minutes
  • WV2: 25 minutes
  • WV5: 35 minutes
  • WV Anniversary: 35 minutes
  1. Is an extension available to clean taller windows?
Yes, an extension pole is available (part number: 2.633-111.0) that can be extended to a maximum of two meters.

You can check it out on Amazon here.

  1. Can the Karcher window cleaner work horizontally as well as vertically?
Yes, it can be used on horizontal surfaces, for example, to remove condensation or moisture, and to clean up spills (up to a maximum of 25 ml).
  1. How long is the warranty period?
Each of the Karcher Window Vac models comes with a two-year warranty.

Karcher Window Vac Review Videos

Click Here for Pricing, Reviews, & More Images of the
Karcher Window Vac

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Author: Jon Maxwell
Senior Writer, ToolCrowd
Jon Maxwell writes about various topics for ToolCrowd, including tool reviews, material advice, common home problems, and general DIY advice and how-to articles. His work has been published in national publications for audiences including consumers, homeowners, and industry experts. Jon has a bachelor's degree in Building Surveying and a master's degree in a branch of Civil Engineering focusing on concrete and steel durability. When he isn't writing for ToolCrowd, Jon enjoys completing DIY tasks in his own home, as well as woodworking in his home workshop, snowboarding, and website development. Contact Jonarrow_right_alt