Door Viewers

Black Door Viewer 180 Degree (55-75mm Door), from our current range.

What is a door viewer?

A door viewer, often called a spy hole or peephole, is a small lens fitted through a door that lets you see who is outside before opening it. Most modern viewers give a wide, 180-degree field of view, so you can see the full width of the doorstep rather than just a narrow tunnel view directly ahead. Door viewers are one of the simplest and most effective pieces of security hardware, and are a sensible addition to any front door without one.

Viewers are sized to the thickness of the door they are fitted through, so it is important to check your door's thickness rather than assuming a standard size will fit.

Where door viewers are used

• Front doors – the standard location, letting you identify a caller before opening the door
• Flats and apartments – particularly useful where a communal entrance means unfamiliar visitors are more common
• Alongside a door chain – often fitted together with a door chain for a simple, layered approach to answering the door safely

Choosing the right door viewer

A few practical points are worth checking before you buy:

• Door thickness – door viewers are sold in ranges to suit specific door thicknesses; check yours before ordering
• Field of view – most modern viewers offer 180 degrees, giving a much wider view than older, narrower designs
• Digital viewers – some viewers now include a small screen or camera link, useful for anyone who finds a traditional optical viewer difficult to use
• Finish – see our Hardware Finishes Guide to match other front door furniture

Related products

Browse our current range of Security & Protection, or see the related Door Chains guide and Locks & Security Guide.

Frequently asked questions

How do I know what size door viewer to buy?

Door viewers are sold with a stated door thickness range, so measure your door before ordering. Fitting a viewer sized for the wrong thickness will not sit flush or seal properly.

Can I fit a door viewer myself?

Yes, most door viewers only need a single drilled hole through the door and can be fitted with basic tools, though care is needed to drill straight and centred.

What's the difference between a standard and digital door viewer?

A standard viewer uses an optical lens you look through directly. A digital viewer uses a small camera and screen, which some people find easier to use and which can offer a wider or clearer view.

Back to the Door Furniture Guide, or explore the full Knowledge Centre.