Few jobs feel more annoying than cleaning a window and finding streaks the second the sun hits it. The good news is that streaks have clear causes, and once you know them, you can clean a window without streaks, inside and out, with just a few simple tools.
The quick version: work on a cloudy day or in shade, use a mild cleaning solution, wipe with a squeegee or lint-free cloth, and dry the edges. Here’s the full method, plus what to do about tall windows.
Why windows streak in the first place
Streaks usually come from three things. Too much cleaner leaves a film. Cleaning in direct sun dries the liquid before you wipe it. And dirty or linty cloths smear instead of lifting grime.
So the fix isn’t a magic product. It’s using less solution, working in the shade and starting with a clean tool. Keep that in mind as we go through the supplies.
What you’ll need
- A squeegee with a fresh, nick-free rubber blade
- A bucket and a soft sponge or microfiber scrubber
- Lint-free cloths, such as microfiber or flat-weave cotton
- A mild soap, or a mix of water and a splash of white vinegar
- A small towel for the sill and edges
- An extension pole for high panes
Skip paper towels and old cotton rags when you can, since they leave lint. And don’t mix vinegar with bleach or ammonia products. That combination can give off harmful fumes.
How to clean the inside of a window
Start by laying a towel along the sill to catch drips. Dust the frame and glass with a dry cloth first, since wet dust turns to mud.
- Wipe the glass with a damp microfiber cloth and your mild solution.
- Pull a squeegee from top to bottom in overlapping strips, or use an S-pattern, wiping the blade after each pass.
- Dry the edges and corners with a cloth.
- Buff any leftover marks with a dry microfiber cloth.
Interior streaks often come from kitchen grease or fingerprints. A tiny bit of dish soap in water cuts that film. Just be sure to rinse it off, because soap itself can leave streaks.
How to clean outside windows
Outside glass picks up pollen, dust and hard water spots. Brush off cobwebs and loose dirt first. Then scrub with the soapy water, rinse with a hose if you can, and squeegee dry.
The trick for the outside is to use the opposite stroke direction from the inside. If you squeegee side to side indoors and up and down outdoors, any streak you see tells you which side it’s on. Hard water spots may need a vinegar solution left on for a minute or two before wiping.
If dirt is caked on siding or frames, a gentle rinse helps. For hard surfaces like patios and driveways, our guide to the best electric pressure washers for driveways is a better fit. Keep high pressure away from glass, since it can break seals or crack panes.
Tall and hard-to-reach windows
Second-story and large picture windows are tricky. Ladders add risk, so a telescoping pole with a squeegee head is safer. Never lean from a ladder or roof to reach a pane.
Another choice is a robotic cleaner that sticks to the glass and wipes on its own. They work best on flat, frameless or framed glass of decent size, and you’ll want to follow the maker’s safety instructions, including attaching the safety rope they come with. Compare the best window cleaning robots for large windows if big panes are your headache.
Don’t forget the tracks and sills
Dirty tracks make clean glass look worse. Vacuum loose grit, then scrub with a small brush and soapy water. A cotton swab handles corners. Wipe it dry so water doesn’t pool.
While you’re cleaning, glance at the floors beneath windows, where drips land. A quick mop works on tile, and our guide to the best steam mops for tile floors covers options. Check the floor’s care instructions before using steam.
Quick fixes for stubborn spots
Some marks laugh at plain soapy water. Dried paint, sticker residue and bug splatter usually need a little patience. Soak the spot with warm water for a minute, then lift it off gently with a plastic scraper held at a low angle. Metal razor blades can scratch some glass and coatings, so check the window type first.
Hard water film, the cloudy haze left by sprinklers, usually responds to a vinegar and water mix left on for a few minutes. If a window looks foggy between the panes, that’s a failed seal, and cleaning won’t fix it. A good time to clean overall is twice a year, in spring and fall, and a quick wipe whenever grime builds. Keeping floors tidy near the windows helps too, and our guide to cleaning hardwood and tile floors shows how.
Frequently asked questions
What’s the best time of day to clean windows?
Early morning, evening or a cloudy day. Direct sun dries the cleaner too fast and causes streaks.
Is vinegar or glass cleaner better?
Both work. Diluted vinegar is cheap and gentle, while store cleaners can cut tougher grease. Use whichever you have, and use only a little.
Why do my windows still streak after cleaning?
Common culprits are too much cleaner, a dirty cloth or a damaged squeegee blade. Try a fresh cloth and a lighter spray.
The bottom line
To clean windows without streaks, use less cleaner, stay out of the sun and finish with a squeegee or clean microfiber. For hard-to-reach glass, a pole or a window robot makes the job safer.