02 / WINDOWS
The best magnetic window insulation kits, for windows that still have to open
Every other film on this site commits you to a sealed window until spring. These do the same job on magnets, at several times the price per window — which is the whole decision.
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Buy a magnetic kit only if the window has to open during winter, or you will reuse it for several years. It costs several times shrink film per window and works by the same mechanism — a still layer of air in front of the glass. Size it on the published maximum opening, not the glass.
The one thing shrink film cannot do
This site recommends shrink film often, and for good reason: it is cheap, the mechanism is real, and a taut heat-shrunk panel is close to invisible. We say so in does window film actually work. But every time we recommend it we have to add the same caveat, because it is total: once the film is on, that window is shut until you cut the film off.
For a spare room, that is fine. For a bedroom that needs airing, a kitchen window, a bathroom, or any window someone in the house will want open on a mild February afternoon, it is not. That is the gap this category fills. A magnetic kit is a film panel held on a magnetic strip around the frame: you lift it off, open the window, and press it back.
The mechanism is identical to shrink film — a trapped layer of still air between the panel and the glass. Nothing about the magnets makes it insulate better. What you are paying for is removability.
Measure the frame, not the glass
Every kit here is published as a maximum fitted size, and the measurement that matters is the flat border of frame you can stick a magnetic strip to — not the pane. Three things catch people out:
- You need a continuous flat border all the way round. Deep decorative trim, a sill obstruction, or a crank handle on a casement can leave one edge with nowhere for the strip to sit, and a panel that is unsupported on one edge lifts.
- Maximum means maximum. These are not trimmed to fit unless the listing says cuttable. A window wider than the published size needs the next kit up, not this one cut down.
- Check the frame material. The strip is adhesive-backed and needs a smooth, clean, degreased surface. Rough timber and chalky old paint are the two surfaces it fails on.
Match the part to your gap
Measure at the widest point. Then read across. If your measurement sits on a boundary, take the larger band — a seal that is slightly too big compresses, and one that is too small does nothing at all.
| Your gap | Part type | Our pick | Price |
|---|---|---|---|
| Standard sash, up to 56 x 35 in | Clear magnetic kit, 0.15 mm EVA |  JOOFAN Magnetic Window Insulation Kit, fits up to 56 x 35 inThe size most double-hung windows need, and the cheapest published film thickness here. | $27.99 · CHECK ON AMAZON |
| Large window, up to 61 x 59 in | Clear magnetic kit, 0.15 mm EVA | JOOFAN Magnetic Window Insulation Kit, fits up to 61 x 59 inSame system, larger published fit. Measure the frame face you will stick the strip to. | $34.99 · CHECK ON AMAZON |
| Window is not a clean rectangle | Cuttable clear kit |  RODENET DIY Magnetic Window Insulation Kit, 48 x 44 in, CuttablePublished as cuttable. Buy the size up from your measurement and trim down. | $32.99 · CHECK ON AMAZON |
| Basement, garage or RV window | Reflective aluminum, opaque |  Maguesh Magnetic Heat-Reflective Aluminum Film Kit, 24 x 36 inBlocks the view as well as the heat. Cheapest kit here, and wrong for a room you sit in. | $19.99 · CHECK ON AMAZON |
| Large window in a room closed for winter | Reflective aluminum, opaque |  Maguesh Magnetic Heat-Reflective Aluminum Film Kit, 51 x 59 inThe same trade at a size you will definitely notice. Only for a room you are not using. | $32.99 · CHECK ON AMAZON |
Clear film or reflective aluminum
Two different products share this shelf and the listings do not always make the difference obvious. Clear film is transparent EVA: you keep the daylight and the view, and the panel is doing the still-air job only. Reflective aluminum film is opaque: it blocks radiant heat, and it blocks the view and the daylight with it.
Reflective film is genuinely useful on a west-facing window in summer, on a basement hopper nobody looks through, or on an RV. It is the wrong product for a living room, and it is worth saying plainly because the price makes it tempting: the reflective kits here are the cheapest on the page.
One more distinction worth keeping straight: reflective film addresses radiant heat, which is a different problem from the air leaks most of this site is about. If your complaint is a draft you can feel at the sash, neither film is the first fix — weatherstrip is.
The picks
Quick picks
Ranked for fit, not for hype. Tap a row to jump to the full write-up, or go straight to the listing.
| # | Product | Best for | Gap range | Price |
|---|---|---|---|---|
| 1 | JOOFAN Magnetic Window Insulation Kit, fits up to 56 x 35 inThe same system in the smaller published size, which covers an ordinary double-hung sash for meaningfully less. | A standard sash window | Not a gap product — published to fit windows up to 56 x 35 in | $27.99 · CHECK ON AMAZON |
| 2 | JOOFAN Magnetic Window Insulation Kit, fits up to 61 x 59 inThe most completely specified kit here — a published film thickness, a full-perimeter magnetic strip and a replaceable film — which is what separates a reusable system from a sheet of plastic. | A large window you still need to open | Not a gap product — a second glazing layer, published to fit windows up to 61 x 59 in | $34.99 · CHECK ON AMAZON |
| 3 | RODENET DIY Magnetic Window Insulation Kit, 48 x 44 in, CuttablePublished as cuttable, which is the feature that matters on the windows the fixed-size kits cannot serve — a bay, a half-round head, or anything the tape measure argues with. | An odd-shaped or non-rectangular window | Not a gap product — published as a 48 x 44 in cuttable panel | $32.99 · CHECK ON AMAZON |
| 4 | Maguesh Magnetic Heat-Reflective Aluminum Film Kit, 24 x 36 inAluminum rather than clear film — it blocks the view and the light along with the radiant heat, which makes it the wrong pick for a living room and the right one for a garage, a basement or an RV. | A window you do not need to see through | Not a gap product — published as a 24 x 36 in reflective panel | $19.99 · CHECK ON AMAZON |
| 5 | Maguesh Magnetic Heat-Reflective Aluminum Film Kit, 51 x 59 inThe large version of the reflective panel, for the big window in a room that is closed up for winter and does not need daylight. | A large window blanked off for the season | Not a gap product — published as a 51 x 59 in reflective panel | $32.99 · CHECK ON AMAZON |
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A standard sash window
JOOFAN Magnetic Window Insulation Kit, fits up to 56 x 35 in
Published gap range
Not a gap product — published to fit windows up to 56 x 35 in
#ad · how we are funded · price as of October 17, 2026
The same system in the smaller published size, which covers an ordinary double-hung sash for meaningfully less.
Where the number comes fromIdentical construction to the larger JOOFAN kit, published for openings up to 56 x 35 in. Measure the frame face rather than the glass, and remember the magnetic strip needs a flat, clean border all the way round — a window with deep trim or a sill obstruction at one edge will not take it cleanly.
- Published fit
- Up to 56 x 35 in
- Published film thickness
- 0.15 mm
- Film
- Transparent EVA, replaceable
- Fixing
- Full-perimeter dual magnetic strips
- Reusable
- Yes
- Mounting
- Magnetic strip adhered around the frame; film panel lifts off and back on
What it does well
- Cheapest way into the magnetic system, and the size most double-hung windows need
- Same published 0.15 mm film and replaceable panel as the larger kit
- Comes off completely at the end of the season with no residue on the glass
Where it fails
- Still several times the per-window cost of shrink film
- Published as a maximum size — a window wider than 56 in needs the larger kit, not this one trimmed
- Adhesive strip on a freshly painted frame can lift paint when removed
Who this is forOne or two ordinary sash windows, in a house where the windows get opened.
A large window you still need to open
JOOFAN Magnetic Window Insulation Kit, fits up to 61 x 59 in
Published gap range
Not a gap product — a second glazing layer, published to fit windows up to 61 x 59 in
#ad · how we are funded · price as of October 17, 2026
The most completely specified kit here — a published film thickness, a full-perimeter magnetic strip and a replaceable film — which is what separates a reusable system from a sheet of plastic.
Where the number comes fromThis is not a gap seal and it does not replace weatherstrip at the sash. It adds a still-air layer in front of the glass, the same mechanism as shrink film, and the number that matters is the opening it covers: published here as up to 61 x 59 in. Measure the frame face you will stick the magnetic strip to, not the glass.
- Published fit
- Up to 61 x 59 in
- Published film thickness
- 0.15 mm
- Film
- Transparent EVA, replaceable
- Fixing
- Full-perimeter dual magnetic strips
- Reusable
- Yes — lifts off and back on
- Mounting
- Magnetic strip adhered around the frame; film panel lifts off and back on
What it does well
- Publishes a film thickness, which almost nothing in this category does
- The panel lifts off in seconds, so the window still opens — the one thing shrink film cannot do
- Film is replaceable, so a scratched panel does not mean a new kit
Where it fails
- Costs many times what shrink film costs per window — if the window is staying shut until spring, a shrink film kit does the same job for a fraction
- The whole system depends on the magnetic strip's adhesive holding to your frame — clean and degrease it or it peels
- Film that is not heat-shrunk taut can look slack and reflective next to a properly fitted shrink kit
Who this is forA large window in a room you ventilate through the winter, or a rental you will reuse the kit in.
An odd-shaped or non-rectangular window
RODENET DIY Magnetic Window Insulation Kit, 48 x 44 in, Cuttable
Published gap range
Not a gap product — published as a 48 x 44 in cuttable panel
#ad · how we are funded · price as of October 17, 2026
Published as cuttable, which is the feature that matters on the windows the fixed-size kits cannot serve — a bay, a half-round head, or anything the tape measure argues with.
Where the number comes fromSold as a 48 x 44 in kit and published as cuttable, so the panel is trimmed down to the opening rather than bought to match it. That is the right approach on a window that is not a clean rectangle. Buy the size up from your measurement and trim, because you cannot add film back.
- Published size
- 48 x 44 in
- Cuttable
- Yes, per the listing
- Film
- Clear
- Fixing
- Magnetic strip
- Other sizes published
- 56 x 35 in and 59 x 61 in
- Mounting
- Magnetic strip around the frame; panel trimmed to fit
What it does well
- Trims to a shape the fixed-size kits cannot cover
- Three published sizes, so you can buy up and cut down
- Same lift-off, reusable principle as the branded kits
Where it fails
- The listing publishes no film thickness, where JOOFAN publishes 0.15 mm
- A cut edge is a weak edge — a trimmed panel is more likely to lift at a corner
- Unbranded reseller listing with no maker data sheet behind it
Who this is forA window that is not a standard rectangle.
A window you do not need to see through
Maguesh Magnetic Heat-Reflective Aluminum Film Kit, 24 x 36 in
Published gap range
Not a gap product — published as a 24 x 36 in reflective panel
#ad · how we are funded · price as of October 17, 2026
Aluminum rather than clear film — it blocks the view and the light along with the radiant heat, which makes it the wrong pick for a living room and the right one for a garage, a basement or an RV.
Where the number comes fromThis is a different product from the clear kits, and the difference is the one you will notice every day: the panel is opaque. Published at 24 x 36 in for home and RV windows. Reflective film addresses radiant heat rather than air movement, so on a genuinely drafty sash it is doing less than weatherstrip would.
- Published size
- 24 x 36 in
- Film
- Heat-reflective aluminum, opaque
- Fixing
- Self-adhesive magnetic strip
- Published use
- Home and RV windows
- Seasons
- Published for winter and summer
- Mounting
- Self-adhesive magnetic strip around the frame; panel lifts off
What it does well
- Cheapest kit on this page by a clear margin
- Opaque film is genuinely useful in summer on a west-facing window
- Small published size suits a basement hopper or a garage window
Where it fails
- It blocks the view and the daylight, so on any window you actually look out of this is the wrong product
- Reflective film targets radiant heat, not the air leaks this site is mostly about
- No published film thickness and no tested performance figure — the maker names no standard
Who this is forA basement, garage or RV window where light and view do not matter.
A large window blanked off for the season
Maguesh Magnetic Heat-Reflective Aluminum Film Kit, 51 x 59 in
Published gap range
Not a gap product — published as a 51 x 59 in reflective panel
#ad · how we are funded · price as of October 17, 2026
The large version of the reflective panel, for the big window in a room that is closed up for winter and does not need daylight.
Where the number comes fromPublished at 51 x 59 in. The same trade as the smaller reflective kit, scaled up: opaque, aimed at radiant heat, and removable on magnets. At this size, consider whether the room is genuinely one you will not use until spring, because a blanked-off window is a noticeable thing to live with.
- Published size
- 51 x 59 in
- Film
- Heat-reflective aluminum, opaque
- Fixing
- Self-adhesive magnetic strip
- Published use
- Home and RV windows
- Seasons
- Published for winter and summer
- Mounting
- Self-adhesive magnetic strip around the frame; panel lifts off
What it does well
- Covers a large opening that the small reflective kit cannot
- Removable on magnets, so the room can be brought back into use
- Cheaper than the large clear kits
Where it fails
- Blanks the window out completely — a serious thing on a large opening
- Targets radiant heat rather than air leaks; weatherstrip at the sash still matters
- No published film thickness or tested figure
Who this is forA spare room or workshop closed up for the winter.
What we would skip, and why
Nobody in this category ever declines to recommend something. That is what makes universal praise worth ignoring. Here is what we would not buy.
Buying these for a window that is staying shut anyway
This is the honest headline and it costs us the sale. Per window, a magnetic kit costs several times what an entire multi-window shrink film kit costs, and once film is on it does the same job by the same mechanism: a still layer of air in front of the glass. If the window will not be opened until spring, buy the film. These kits earn their price only when the window has to open, or when you will genuinely reuse them for several winters.
Expecting a magnetic kit to fix a rattling sash
It will not, and neither will shrink film. A panel across the front of the window stops air moving at the glass; it does nothing about air travelling through the gap between the sash and its frame, because that gap is behind the panel. If your sash has play in it when locked, the fix is weatherstrip or rope caulk in the gap — the parts are in best window weather stripping tape and rope caulk vs V-seal vs film. Do that first, then decide whether you still want a panel.
Sticking the magnetic strip to a freshly painted frame
The whole system hangs off an adhesive strip around the frame, and adhesive on emulsion that has not fully cured takes the paint with it in spring. Anything painted within the last month or so is a bad candidate. Clean and degrease the frame face first whatever its age, because the commonest failure in this category is not the film — it is the strip letting go at one corner in January.
Judging these on the energy claims
Listings in this category talk about heat retention and savings without naming a test, a temperature or a window type, which is why you will find no percentage anywhere on this site. What you can verify is the film thickness (one maker here publishes 0.15 mm and the others publish none), the fitted size, and whether the film is clear or opaque. Those are the specifications we rank on.
How we picked
- We rank on published fit first, because a panel that does not cover the opening does nothing and these are sold in fixed maximum sizes. Every pick states the opening it covers.
- Published film specification second. One maker publishes a film thickness (0.15 mm) and a replaceable panel; the others publish neither, and the picks say so rather than assuming they match.
- Clear against reflective third, treated as a use decision rather than a ranking. Clear film keeps the view; aluminum film blocks it along with the radiant heat. Neither is better — they are for different windows.
- We did not test these, and we publish no energy figures because no maker here names a test. Prices come from the live price layer and are dated; the full method is published.
We have not tested these products and we do not claim to have. The full method, including what we refuse to claim, is on how we pick.
Complete the kit
The parts that decide whether the seal you just bought actually holds. Skip these and you will be doing the job again in March.
Removing old weatherstrip adhesive
Goo Gone Pro-Power Adhesive Remover Spray, 16 fl oz, with Scraper
The step everybody skips: the new tape will not stick to the residue the old tape left behind.
Seasonal window sealing
Frost King B2 Mortite Fingertip Caulking Cord, 1/8 in x 90 ft
Rope caulk: pliable putty you press into a gap in October and peel out in April, leaving no adhesive behind.
Door and window frame sides
M-D Building Products V-Flex Window Seal Weatherseal, 3/8 in x 17 ft, White
V-strip folds into the gap and springs back, so it seals a jamb that never closes to exactly the same place twice.
#ad · how we are funded · price as of October 17, 2026
What about real interior storm windows?
People searching for a removable second glazing layer often mean an interior storm window — a rigid acrylic or glass panel in a compression-fit frame that presses into the window opening. They are a genuinely good product and considerably more substantial than any film, built to your measurements by specialist makers.
We do not rank them here for one reason: they are made to measure and sold direct by their makers rather than off a shelf, so we cannot verify a current price or availability for a specific item the way we can for everything else on this site. Publishing a pick we cannot check would break the rule the rest of these pages are built on. If a made-to-measure panel is what you want, go to the makers directly and get a quote for your openings.
The magnetic kits on this page are the off-the-shelf version of the same idea: a removable second layer, at a fraction of the cost and a fraction of the substance. For a window you open, that is often the right trade.
Where this sits in the order of work
The order we publish in how to seal windows for winter does not change for these kits. Tighten the sash lock, which is free. Seal the gap between sash and frame. Caulk the frame-to-wall joint if it is open. Only then add a panel over the glass, whether that panel is shrink film or a magnetic kit.
Doing it the other way round — panel first, sealing later — hides the leak you have not fixed behind a sheet of plastic and makes it harder to find. It also produces the commonest complaint about window film of either kind: that it went on and the room still felt cold, because the air was never coming through the glass in the first place.
Questions people actually ask
- Are magnetic window insulation kits better than shrink film?
- Not at insulating — they work by the same mechanism, a still layer of air in front of the glass. They are better at one specific thing: coming off and going back on, so the window can still be opened. They cost several times as much per window, so the honest answer is to use film on windows that stay shut and magnetic kits on the ones you open.
- Do magnetic window kits damage the frame?
- The risk is the adhesive strip rather than the magnets. On sound, cured paintwork it usually comes away cleanly. On paint applied within the last month or so, or on chalky old paint, it can lift the surface. Clean and degrease the frame first, and if the paint is new, wait.
- Can I reuse a magnetic window insulation kit next year?
- That is the point of them, and the main argument for the price. The film panel lifts off and stores flat, and one kit here publishes a replaceable film so a scratched panel does not mean a new kit. The part that usually does not survive is the adhesive strip, which often has to be renewed if you remove it from the frame.
- Will a magnetic kit stop a draft from my window?
- Only the part of it moving at the glass. Air coming through the gap between the sash and the frame passes behind the panel and into the room regardless. If your sash rattles when locked, seal that gap first with weatherstrip or rope caulk, then decide whether you still want a panel over the glass.
Read next
The best window insulation kits, by published coverage
Shrink-film kits ranked by published coverage and film weight, plus the frame checks that decide whether the tape holds.
Does window insulation film actually work?
Yes on single glazing, much less on modern units, and not at all with a gap in the tape. The mechanism, explained.
Draft fixes for renters that leave no trace
Rope caulk, stoppers and removable film — the fixes that come out clean at move-out.
How to seal windows for winter from the inside
The order of work that stops you filming over a leak you could have closed for free.