How to Clean Windows Without Streaks

Streaks are almost always leftover residue: too much detergent, dirty water, minerals from hard water drying on the glass, or a cloth that pushes dirt around rather than lifting it. Cleaning in bright sunshine makes it worse, because the glass dries before you can wipe it off.

A dry, overcast day is ideal. If the sun is shining directly on a window, clean it when that side of the house is in shade. Avoid freezing days, when water can freeze on the glass.

You don't need much, but quality matters:

Brush or vacuum the dust and cobwebs from frames and sills first, so you don't turn them into mud. Wet the glass with the applicator or sponge, working the dirt loose. Then, starting at a top corner, draw the squeegee across or down the glass in overlapping strokes, wiping the blade on a cloth after each stroke.

Dry the edges and corners with a microfibre cloth, and buff away any small marks with a second, dry cloth. Clean the frame and sill last, as drips will have landed there.

Inside, a squeegee isn't always practical. A damp microfibre cloth wrung out well, followed by a dry one, works on most glass and mirrors. Spray glass cleaner onto the cloth rather than directly onto the glass to avoid drips onto frames and sills.

If your windows stream with condensation on winter mornings, wipe it away with a cloth or window vacuum and dry the sills, otherwise mould can grow on frames and seals. Ventilating rooms, using extractor fans and drying clothes outside or in a vented space all help reduce it.

Not usually. A few drops of washing-up liquid in a bucket of warm water works perfectly with a squeegee, which is what many professional window cleaners use. Spray glass cleaners are convenient for small windows and mirrors indoors, but they're not essential.

In hard water areas, minerals in tap water can leave spots as the glass dries. Drying with a microfibre cloth before the water evaporates, or rinsing with a little filtered or distilled water, helps. That's also why professional water-fed poles use purified water – it dries without leaving marks.

Handheld window vacuums – a squeegee with built-in suction – have become popular for both cleaning and clearing condensation. They make it easier to avoid drips on sills and floors, and they're quick on large panes and shower screens.

They're not essential, and they work best combined with a good applicator or cloth. If you have lots of large windows or condensation every morning, they can save time.

Don't lean out of upstairs windows or balance on ladders to reach outside glass. Tilt-and-turn and some sash windows let you clean both sides from inside. For everything else, a professional window cleaner with a water-fed pole can clean upstairs windows safely from the ground. See our window cleaning service page for what's included and how rounds work.