Inside Mount vs. Outside Mount: How to Choose the Right Fit for Your Windows (The Mistake-Free Guide)
You’ve picked the perfect fabric. You’ve chosen the color. You’re ready to order. But then you see the dropdown menu: “Mount Type: Inside or Outside?”
This is the single most common stumbling block for homeowners buying custom window treatments. Making the wrong choice here doesn’t just mean your blinds might not fit; it can completely change the look of your room and how well your blinds function.
At LazBlinds, we want your installation to be flawless. In this guide, we’ll break down the differences between Inside Mount and Outside Mount so you can measure with confidence.
Option 1: Inside Mount (The Clean & Custom Look)
What is it? The blind or shade is installed inside the window frame. The headrail sits tucked away within the casing, flush with the wall.
✅ The Pros:
- Clean Aesthetic: It looks neat, tailored, and high-end. It showcases your window molding rather than hiding it.
- Space Saving: Because the blinds are recessed, they don’t protrude into the room. This is ideal for windows near furniture.
- Layering: It allows you to add drapes or curtains on the outside for a layered, designer look.
❌ The Cons:
- Light Gaps: There will always be a tiny gap on the sides so the fabric doesn’t rub against the frame. If you need 100% total darkness, this might be an issue.
- Requires Depth: Your window frame must be deep enough (usually at least 2-3 inches) to house the mechanism.
🏆 Best For:
- Modern, minimalist interiors.
- Windows with beautiful wood trim you want to show off.
- When you plan to add decorative curtains over the blinds.
Option 2: Outside Mount (The Problem Solver)
What is it? The blind is installed on the wall above the window frame or on the trim itself. It covers the entire window opening and overlaps the edges.
✅ The Pros:
- Maximum Blackout: Because the fabric overlaps the window edges (we recommend adding 2-3 inches on each side), it blocks light leakage much better than inside mounts.
- The “Big Window” Illusion: You can mount the shades higher (closer to the ceiling) to make your windows look taller and your ceilings look higher.
- Hides Imperfections: If your window frame is old, crooked, or unattractive, an outside mount covers it up completely.
❌ The Cons:
- Conceals Molding: You won’t see your window trim when the shades are down.
- Hardware Visible: The installation hardware is more exposed (though a valance can hide this).
🏆 Best For:
- Bedrooms and Media Rooms where blocking light is priority #1.
- Shallow windows that aren’t deep enough for an inside mount.
- Making small windows appear larger.
Decision Checklist: Which One is Right for You?
Still not sure? Grab a ruler and answer these 3 questions:
- Do you have enough depth? Check the “Minimum Depth Requirement” on the product page (usually 2-3 inches).
- If NO: You must choose Outside Mount.
- If YES: You can choose either.
- Is your window square? Measure the diagonal corners. If your window frame is significantly crooked (common in older homes):
- Outside Mount is safer and more forgiving.
- Do you hate light gaps?
- If you are a light sleeper, Outside Mount offers better coverage.
A Note on Measuring
Crucial Warning: The way you measure changes completely based on your decision!
- For Inside Mount: Measure the exact window opening width. Do not make deductions. Our factory will automatically subtract a tiny amount to ensure it fits.
- For Outside Mount: You specify the exact size you want the blind to be. You need to add the extra width for overlap yourself.
Ready to measure? Don’t guess! Follow our step-by-step instructions here: Installation Guides – How to Measure.
Conclusion
There is no “wrong” answer—only the answer that fits your specific window and style goals. Whether you choose the sleek Inside Mount or the functional Outside Mount, LazBlinds guarantees a perfect custom fit.
Shop confidently now that you know the difference! Browse All Window Treatments
