How to Clean Windows: The Best Window Cleaning Solution and Method for Streak-Free Glass

Want to know how to clean windows without leaving a single streak? Use a mild window cleaning solution, a squeegee and a microfibre cloth, and clean on a dull, dry day. It's the same simple kit professional window cleaners use, and it costs just pennies per clean.

Read on for the best window cleaning solution for every job, from everyday dirt to stubborn limescale spots. You'll learn how to mix your own window washing solution, use a squeegee like a pro and avoid the small mistakes that cause smears.

What Is the Best Way to Clean Windows?

The best way to clean windows is to wash the glass with a mild soapy solution, squeegee it dry from top to bottom, and dry the edges with a microfibre cloth. Sprays and paper towels mostly push dirt around. A squeegee lifts the dirt and the water off the glass in one pull.

Here's why that matters. Streaks are leftover residue: too much soap, minerals from tap water, or dirt dissolved in the cleaner. Remove the liquid quickly and completely, and there's nothing left to dry into marks.

What Is the Best Window Cleaning Solution?

The best window cleaning solution for most homes is warm water with a small squirt of washing-up liquid. This mix cuts grease, loosens dirt and rinses off cleanly when you squeegee.

The secret is using less than you think. Around half a teaspoon of washing-up liquid in 4 litres of warm water is plenty. Too much soap is the most common cause of a cloudy film on glass.

Window Washing Solutions Compared

Each window washing solution suits a different job. Find your problem below to see which solution to use and how to mix it.

Got everyday dirt and fingerprints?
→ Use washing-up liquid: ½ teaspoon in 4 litres of warm water.
⚠ Extra soap leaves a cloudy film, so keep the mix weak.

Got white limescale spots or greasy film?
→ Use white vinegar: 1 part vinegar to 1 part warm water.
⚠ Neat vinegar can harm seals and etch marble or limestone sills.

Need a quick touch-up on a mirror or small pane?
→ Use shop-bought glass spray, ready to use from the bottle.
⚠ Ammonia-based sprays can leave a haze.

Cleaning outside glass on upper floors?
→ Use pure (deionised) water with a water-fed pole.
⚠ Pure water needs a filter system or a professional window cleaner.

Is Vinegar or Washing-Up Liquid Better for Windows?

Washing-up liquid is better for general dirt, and vinegar is better for limescale spots and the greasy film old sprays leave behind. Many people get the best results using both, one after the other.

Vinegar is worth having if you live in a hard water area, such as London. Hard tap water leaves chalky white spots as it dries. The mild acid in vinegar dissolves those minerals. Always dilute it, though. Neat vinegar is strong enough to harm some frames and seals, and it can etch marble or limestone sills.

What Tools Do You Need to Clean Windows?

You need a squeegee, a scrubber or sponge, a bucket and two microfibre cloths. A decent starter kit costs roughly £40 in the UK, and it lasts for years.

• A squeegee of 25–35 cm with a sharp, smooth rubber blade

• A strip washer or sponge to work the solution over the glass

• A bucket wide enough to dip the squeegee into, ideally 10 litres or more

• Two microfibre cloths: one to wipe the blade, one to dry the edges

• A soft brush or vacuum nozzle to clear frames, sills and tracks

Skip the paper towels and newspaper. Paper towels leave lint behind. Newspapers can transfer ink onto white uPVC frames.

How to Clean Windows Step by Step

Follow these seven steps for streak-free window cleaning, inside or out. Once you've got the rhythm, a standard window takes about five minutes.

1. Pick a Dull, Dry Day

Clean windows on an overcast day or while the glass is in shade. Strong sun dries the solution before you can squeegee it off, and that leaves spots. Early morning works well on south-facing windows.

2. Clean the Frames and Sills First

Vacuum or brush out the tracks and sills. Then wipe the frames with your soapy water. If you do the glass first, dirty drips from the frames will run straight down your clean pane.

3. Wash the Glass

Dip your scrubber, squeeze out the excess and wash the whole pane. Work into the corners and along the edges, where grime builds up. Soak bird droppings for a minute instead of scraping them dry.

4. Squeegee from Top to Bottom

Wipe a dry strip about 3 cm wide down one side of the glass. Start each stroke from that dry strip and pull the squeegee straight down. Overlap each stroke by about 5 cm, so you leave no wet lines between passes.

5. Wipe the Blade After Every Stroke

Wipe the rubber blade on a dry microfibre cloth after each pull. A wet, dirty blade puts a fresh line of water back on the glass.

6. Dry the Edges

Run a folded, dry microfibre cloth around the edges of the pane. Then wipe the sill to catch the last drips.

7. Check the Glass from an Angle

Stand to the side and look across the glass. Streaks show up best at an angle. Buff any marks away with a clean, dry cloth.

How to Clean Windows Inside and Outside

The method stays the same on both sides, but the dirt is different. Inside glass collects fingerprints, cooking grease and condensation film. Outside glass collects traffic grime, pollen and bird droppings.

Cleaning Windows on the Inside

Use less water indoors so you don't soak the sill or the floor. Lay a towel along the sill first. For small panes, a spray bottle of your solution and two microfibre cloths work as well as a squeegee.

Cleaning Windows on the Outside

Rinse the glass with a hose first to knock off loose grit. Grit dragged across glass can scratch it. Avoid pressure washers on windows, because a strong jet can force water past the seals.

How Do You Clean Upstairs Windows Safely?

The safest way to clean upstairs windows is from the ground with an extension pole or a water-fed pole. Water-fed poles spray pure water through a brush, and the glass dries without spots.

If you must use a ladder, follow the Health and Safety Executive's ladder guidance. Set the ladder at a 1-in-4 angle, keep three points of contact and never overreach. Have someone foot the ladder for you. For anything above the first floor, a professional is usually the safer choice.

Why Do My Windows Streak After Cleaning?

Windows streak after cleaning because residue dries on the glass before you remove it. These five habits cause most streaks:

• Using too much soap, which leaves a cloudy film

• Cleaning in direct sun, which dries the solution into spots

• Using a worn squeegee blade, which leaves thin lines (replace the blade every few months)

• Washing microfibre with fabric softener, which coats the fibres so they smear

• Skipping the frames, which sends dirty drips down clean glass

DIY Window Cleaning Hacks That Actually Work

These professional window cleaning tips cost almost nothing:

• Squeegee in opposite directions. Go vertical outside and horizontal inside. A leftover streak's direction tells you which side it's on.

• Add a splash of rubbing alcohol in winter. Alcohol helps the solution dry faster and stops it freezing on cold glass.

• Wrap a cloth around a butter knife. The wrapped knife gets grime out of tight frame corners and sliding door tracks.

One caution: self-cleaning glass, such as Pilkington Activ, has a special coating. Avoid abrasive pads and silicone-based cleaners on it, and check the manufacturer's care advice.

How Often Should You Clean Your Windows?

Most UK homes need their outside windows cleaned every 4 to 8 weeks, and inside windows every 2 to 3 months. Homes near busy roads, building sites or the coast often need a clean every month. Regular cleaning is quicker, because grime never gets the chance to bake on.

What to Remember

• Use a weak solution: ½ teaspoon of washing-up liquid in 4 litres of warm water.

• Clean on a dull, dry day, so the solution doesn't dry into spots.

• Clean the frames and sills before the glass.

• Squeegee from top to bottom, and wipe the blade after every stroke.

• Use diluted vinegar for limescale spots in hard water areas.

Frequently Asked Questions About Cleaning Windows

Can You Clean Windows in Winter?

Yes, you can clean windows in winter, as long as the temperature is above freezing. Pick a dry, mild day around midday, when the glass is warmest. Use lukewarm water rather than hot, because hot water on cold glass can cause stress cracks. A splash of rubbing alcohol helps stop the solution freezing.

How Do You Remove Black Mould from Window Seals?

Remove black mould from window seals with warm soapy water and a soft cloth, then dry the area fully. For stubborn patches, use a mould remover made for silicone. Wear rubber gloves and open the window while you work. Wiping away condensation each morning helps stop the mould coming back.

Why Is There Condensation Between My Double-Glazed Panes?

Condensation between double-glazed panes means the seal around the glass unit has failed. Moist air has leaked into the gap, so no amount of cleaning will remove the moisture. The fix is to replace the sealed glass unit, which is usually cheaper than replacing the whole window frame.

How Do You Remove Stickers and Paint from Window Glass?

Remove stickers and paint from window glass with a glass scraper held at a low angle on wet glass. Soak the area with soapy water first, then push the blade forward in short strokes. Never scrape dry glass. Avoid scrapers on toughened or self-cleaning glass, because the blade can leave scratches.

Do Tenants Have to Clean Windows at the End of a Tenancy?

Tenants usually have to clean the inside windows at the end of a tenancy. The property should be returned as clean as it was at check-in, allowing for fair wear and tear. Outside windows, especially upstairs, are often the landlord's job. Check your tenancy agreement and check-in inventory to be sure.

How Much Does Professional Window Cleaning Cost in Bristol and London?

Professional window cleaning with ProTouchs starts from £35 per property in Bristol and London. The final price depends on the number of windows, the property size and whether you need inside, outside or both. You can also add window cleaning to a one-off deep clean or end of tenancy clean.

Get Streak-Free Windows Without the Ladder

Now you know how to clean windows properly. Use a weak soapy solution, a sharp squeegee and dry microfibre, and pick a cloudy day. Get those right and your glass will stay clear for weeks.

Don't fancy the ladder work? ProTouchs offers professional window cleaning in Bristol and London, inside and out, from £35 per property. You can add windows to a one-off deep clean or an end of tenancy clean on the same visit. Get your fixed quote today.