Streaks often come from liquid drying before you remove it, a dirty cloth or an imperfect squeegee edge. Start on a shaded, cool pane so you have time to work. Keep the inside and outside cleaning cloths separate when the exterior has more grit.
Remove loose grit, wash with a glass-compatible solution, then remove the liquid before it dries and wipe the edges.
Go straight to the stepsBefore you begin
Clean only glass you can reach from a safe standing position. Do not lean through an open window. Follow special instructions for tinted, coated or filmed glass; do not use blades or abrasive pads as a default.
What you’ll need
- Window care instructions
- Soft clean cloths
- Compatible glass cleaner
- Squeegee with an undamaged rubber blade
- Towel to protect the sill
Let’s do this
Step by step
- 01
Prepare the pane and sill
Remove loose dirt with a gentle method approved for the window. Lay a towel on the sill and move curtains or blinds aside. If a screen blocks the glass, remove it only by its intended release mechanism.
- 02
Choose and test the cleaner
Use the window maker’s approved glass-cleaning method. Apply a little in an inconspicuous area when the finish or film is unfamiliar. Avoid soaking wood frames, seals and adjacent furnishings.
- 03
Wash a manageable area
Wet the glass evenly with the compatible solution and a soft cloth or applicator. Loosen ordinary soil without scouring. Treat stubborn construction residue as a separate problem; dragging trapped grit or a razor across coated glass can leave lasting damage.
Remove water before it dries. Use the instructions below for the full procedure.Open full-size image - 04
Squeegee from the top
Use overlapping passes to remove the liquid, wiping the blade with a clean cloth between passes. Keep the rubber edge in contact with the pane and do not press hard enough to distort it. A lint-free cloth is an alternative for small panes.
- 05
Dry the edges and inspect
Wipe the perimeter, sill and drips with a separate dry cloth. Look across the glass from an angle. If there is a streak, clean the tool and redo that small area rather than applying more product across the whole window.
Diagnose a streak before buying another cleaner
Straight repeat lines can point to dirt or damage on the squeegee blade. Haze across the whole pane can indicate cleaner residue. A sunny hot pane may simply dry too fast. Change one variable on a small section to find the cause.
Screens and tracks are separate jobs
Wash or vacuum screens according to their care instructions and let them dry before reinstalling. Keep track drainage openings clear. Do not pack them with caulk while trying to improve the appearance of the sill.
A quick final check
- Glass cool and shaded
- Grit removed gently
- Correct cleaner for coating
- Edges and sill dried
Common questions & sticking points
Is vinegar safe on every window?
No universal mixture suits every coating, film, seal and surrounding finish. Use the window or film maker’s care directions.
Do I need a ladder for outside glass?
Do not use an unsafe reach to finish the job. Use an approved accessible cleaning position or arrange professional help for high or awkward windows.
Sources & further reading Optional
References used to check this guide. Follow your product’s own safety instructions where its design differs.
Last source check: September 24, 2026
