Inside Mount vs Outside Mount Blinds: Which Is Better?

Quick answer: Inside mount blinds fit inside the window frame for a clean, built-in look — but require at least 1.5 to 2 inches of clear frame depth depending on the product. Outside mount blinds install above and beyond the frame, cover more glass, block more light, and work on any window regardless of depth. For blackout performance, outside mount is almost always the better choice. For a streamlined appearance where trim stays visible, inside mount wins — as long as your frame is deep enough and square.

What Is The Difference Between Inside Mount And Outside Mount Blinds?

The main difference between inside mount vs outside mount blinds is where the window covering is installed. Inside mount blinds sit within the recessed area of the window frame. Outside mount blinds attach to the wall or trim above and outside the window opening, covering the full frame and beyond.

The choice affects appearance, light control, privacy, and whether the product will even physically fit your window.

What Are Inside Mount Blinds?

Inside mount blinds are installed within the recessed area of the window frame. The blind sits flush with or slightly inside the frame opening, creating a streamlined appearance that keeps your window trim and molding fully visible.

This style works well in modern and minimalist interiors where a clean line matters. The trade-off is that inside mount blinds depth requirements vary by product — cellular shades typically need at least 1.5 to 2 inches of clear depth, while faux wood blinds may need 2.5 to 3 inches or more. If your frame is shallower than the product requires, inside mount isn’t the right fit.

Advantages Of Inside Mount Blinds

• Clean, custom-built appearance that follows the window shape
• Keeps window trim and decorative molding visible
• Takes up no wall space around the window
• Works well with modern and minimalist interiors

Things To Consider With Inside Mount

• Frame must be deep enough for the product — measure before ordering
• Small light gaps will appear around the edges — unavoidable with inside mount
• Frame must be reasonably square; a window out of square across a wide span creates visible gaps when the shade is lowered
• Not suitable for shallow frames or non-standard window shapes

What Are Outside Mount Blinds?

Outside mount blinds are installed on the wall or trim above the window opening, extending beyond the sides of the frame. This gives you full control over how much of the wall the blind covers and how far above the window the headrail sits.

A common question is how wide should outside mount blinds be: as a rule, extend at least 2 to 3 inches beyond the window frame on each side to minimize side light gaps, and position the headrail 2 to 4 inches above the frame to cover the gap between the glass and where the blind rests when raised.

Advantages Of Outside Mount Blinds

• Covers more glass area, significantly reducing edge light gaps
• Makes windows appear larger — especially useful in smaller rooms
• Works on any window regardless of frame depth
• Better privacy coverage, particularly at the sides
• Only viable option for shallow frames that can’t accommodate inside mount

Things To Consider With Outside Mount

• Requires enough clear wall space above and beside the window for brackets
• More visually prominent — the blind and headrail are visible from outside the room
• May cover some window trim depending on how far out you extend

Inside Mount vs Outside Mount: Which Is Better For Bedrooms?

For bedrooms where maximum darkness and privacy matter, outside mount is almost always the better choice. The shade extends past the frame on all sides, substantially sealing off the edge light gaps that are inherent with inside mount. For blackout performance specifically, see our Blackout vs Light Filtering Blinds guide.

Inside mount can still work in bedrooms when appearance is the priority and you’re pairing the blind with blackout curtains that cover the edge gaps.

Inside Mount vs Outside Mount For Blackout and Cellular Shades

For blackout roller shades and room-darkening window treatments, outside mount consistently outperforms inside mount on light control — the shade sits flush against the wall rather than within the frame, which closes off the side channels where light leaks in.

For inside vs outside mount cellular shades specifically, the insulation difference is minimal — both retain the honeycomb air pockets that buffer heat and cold. The light-gap difference is the bigger practical factor. Outside mount cellular shades vs inside mount for insulation: both work well, but outside mount adds a slight edge by reducing the cold-air channel around the frame perimeter in winter. See our Honeycomb Cellular Shades Complete Guide for full product options.

For inside vs outside mount Roman shades and inside vs outside mount roller shades: the same principle applies. Outside mount covers more glass and reduces light gaps; inside mount gives a cleaner, more architectural look.

How To Measure For Inside Mount Blinds

Accurate measurement is critical for inside mount because the product must fit within the frame opening.

• Measure the inside width at the top, middle, and bottom — use the narrowest measurement
• Measure the height from the top inside edge to the sill at the left, center, and right
• Confirm the frame depth meets the product’s minimum requirement before ordering
• Check squareness: measure corner-to-corner diagonally; if the two diagonal measurements differ by more than 0.25 inches, the frame is out of square and inside mount may show a gap on one side

For a full step-by-step walkthrough, see our Measuring & Installation Guide.

How To Measure For Outside Mount Blinds

Outside mount gives you more flexibility because you’re not constrained by the frame opening.

• Decide how far beyond the frame you want the blind to extend on each side (2–3 inches is standard)
• Measure the total width you want covered, including those extensions
• Decide how high above the frame to mount the headrail (2–4 inches is typical) and add that to your height measurement
• Check for nearby handles, trim, or window cranks that could interfere with the bracket placement

Should Blinds Be Mounted Inside Or Outside The Window Frame?

The right answer depends on your window and your priorities:

• Choose inside mount if you want a clean built-in look, your frame is deep enough, and light gaps at the edges are acceptable.
• Choose outside mount if you want better light control, maximum privacy, your frame is too shallow, or you want the window to appear larger.
• When in doubt, outside mount is the more forgiving choice — it works on every window and gives you better coverage by default.

Frequently Asked Questions

Are inside mount blinds better than outside mount?

Neither is universally better. Inside mount gives a cleaner, more architectural appearance. Outside mount gives better light control, privacy, and works on windows that are too shallow for inside mount. The right choice depends on your frame depth, light priorities, and style preference.

What is the minimum depth for inside mount blinds?

It depends on the product. Cellular shades typically need 1.5 to 2 inches of clear frame depth; faux wood blinds generally need 2.5 to 3 inches or more. If your window frame doesn’t meet the minimum, outside mount is the correct solution — not a workaround but the standard choice for shallow frames.

What if my window is too shallow for inside mount?

Switch to outside mount. Install the headrail on the wall above the frame and extend the blind 2 to 3 inches past the frame on each side. This gives you full coverage with no frame-depth constraint and actually improves light control compared to a forced inside mount on a shallow frame.

How wide should outside mount blinds be?

Extend at least 2 to 3 inches beyond the window frame on each side. This overlap closes the side light channels that would otherwise let light in around the edges. For blackout applications, going 3 to 4 inches past the frame on each side gives the best performance.

Do outside mount blinds block more light?

Yes. Outside mount covers the full frame and extends past it, eliminating the side and top light gaps that are inherent with inside mount. For any room where light control is a priority — bedrooms, media rooms, nurseries — outside mount is the more effective installation.

Which mount is better for blackout blinds?

Outside mount. Blackout fabric stops light transmission through the shade itself, but inside mount still allows light to enter through the gap between the shade and the frame on all sides. Outside mount closes those channels and is the standard recommendation for true blackout performance.

What are the most common inside mount mistakes?

The three most common: ordering without checking frame depth (the blind physically won’t fit or will stick out), not measuring at multiple points (frames are rarely perfectly square or uniform in width), and expecting inside mount to perform like blackout when the edge gaps let in more light than the fabric blocks. A fourth: not checking for window hardware — locks, latches, or security bars — that can prevent outside-mount brackets from sitting flush against the wall.

Can I convert from inside mount to outside mount after installation?

Yes — you’ll need different brackets and the headrail will need to be long enough to extend past the frame. If you’re ordering new, specifying outside mount from the start gets you the right headrail width. If you already have a blind that was inside-mounted, check whether the headrail is long enough to span the outside-mount width you need before re-ordering brackets.

Shop Custom Blinds & Shades

• Shop Cellular Shades — available in inside and outside mount
• Shop Roller Shades — blackout and light filtering options
• Shop Roman Shades — linen and fabric options
• Shop Venetian Blinds — faux wood and aluminum
• Shop Zebra Shades — day and night light control

All UAM Blinds window treatments are custom-made to your exact measurements. Free shipping on orders $99+, ships to the US, Canada, and Australia. Questions about mount type or measuring? Email us at support@uamblinds.com.