Drafty window?

A cold draft or chilly spot by a window is usually worn weatherstripping or cracked caulk, both cheap to fix yourself. If the air is coming from the frame or wall around the window, or the window is old, the fix is bigger.

Not sure which one it is? Snap your window and we’ll narrow it down.

Is the cold air coming from a door instead?

Doors leak at the sweep and the frame, not the glass. Drafty exterior door

Likely causes

Worn or missing weatherstripping
Most commonEasy DIY
You feel air along the edge of the sash where it meets the frame, the foam or vinyl seal is flattened, cracked or gone, or a sheet of paper slides out easily when the window is shut.
Part: $5–30 per window
Failed caulk at the frame or trim
CommonEasy DIY
Cracked, shrunken or peeling caulk where the trim meets the wall or the frame, with air or a visible gap behind it. Often worst on the windward side of the house.
Part: $5–15 (a tube)
Sash not closing or locking tight
CommonModerate DIY
The lock is open or loose, the sash rattles, or it sits slightly crooked. Locking it pulls the sash against the seal; a window that won't lock fully may be swollen, painted shut or out of square.
Part: $10–40 (a new lock or latch)
Gaps around the frame (missing insulation)
Less commonCall a pro
The draft comes from the gap between the frame and the wall rather than the window itself, the trim is cold to the touch, or you can feel air behind the casing.
Part: $100–600 (pro resealing; about $150 for a typical window)
Old single-pane or failed window unit
Less commonCall a pro
Glass that feels cold across the whole pane, warped or rotted frames, loose glazing putty, or a window that has never sealed well. Sealing tweaks help only a little.
Part: $300–1,200 per window, installed (about $750 on average)

Quick checks

Don't caulk or seal over a window that's needed as a bedroom fire exit: it has to open easily in an emergency, so use only removable measures there. Windows in older houses may have lead paint. Don't sand or scrape painted frames or sashes; clean with a damp cloth and, if the paint is chipping, have a lead-safe pro handle it.

On a windy day, hold a lit candle or stick of incense near the edges of the sash and frame. If the flame or smoke flickers sideways, there's your leak. Keep it clear of curtains.
Shut the window on a strip of paper (or a dollar bill) at several spots. If it slides out with no resistance, the seal isn't tight there.
Check the sash lock is fully engaged and the sash is pulled tight against the frame.
Look for cracked, shrunken or missing caulk around the outside and inside trim, and feel along it for moving air.
For a quick stopgap, press removable rope caulk into the gap, or tape clear shrink film over the inside of the frame.
If the whole house is cold rather than one window, it may be losing heat faster than it makes it, so also check the furnace.

Sharpen the read

Find where your window is leaking, for free

No account, no phone number. Fixology’s AI reads your photo and tells you what’s likely wrong, how worried to be, and whether it’s a DIY fix.

Snap one of these:

the window up close where you feel the draft (the edge of the sash or frame)
the whole window, so we can tell its type
any cracked caulk or worn seal around the frame

Add a note or more photos next. Nobody calls you.

When to call a pro

The draft is coming from the gap around the frame, the frame or sill is rotted or soft, the glass is cracked or the window can't be made to close, or sealing hasn't fixed it and you're weighing replacement. For lifespan and upkeep, see the window guide.

Typical cost: Pro weatherstripping or caulking runs about $50–150 per window, resealing the gap around a frame $100–600, and a whole new window $300–1,200 installed (about $750 on average). Rot repair runs $250–800.

Sources: HomeAdvisor: How Much Does Window Repair Cost?, HomeAdvisor: Weatherstripping replacement cost, Angi: How to Fix Foggy Windows

After a scan, Fixology can also help you find pros near you.