How to Choose a Mezuzah Case and a Kosher Scroll

The case is not the mezuzah. What makes a scroll kosher, which size fits your door, and how to hang it — a clear guide for first-time buyers.

Buying a first mezuzah is easy to get wrong online. Most listings show a beautiful case, but the case is only the housing. The mitzvah is the scroll inside it. Here is what to look for.

1. The scroll is the mezuzah

A mezuzah is a small parchment (klaf) with two passages from Deuteronomy — the Shema (6:4–9) and Vehaya (11:13–21). To be kosher it must be written by hand, in special ink, by a trained scribe (sofer), with every letter formed correctly.

A printed or photocopied scroll is not kosher, and printed scrolls are sold widely online at very low prices. When you buy a scroll, ask for:

A hand-written scroll from a known scribe.
Proof it was checked (magiah) by a second expert, and ideally by computer for missing or touching letters.
A certificate that names who wrote and who checked it.

Scrolls are sold in grades. A standard kosher scroll is valid; a mehudar scroll is written with extra care and beauty. Both fulfil the mitzvah.

2. Match the case to the scroll

Common scroll sizes are 7, 10, 12 and 15 cm. The scroll is rolled, so the case's inner cavity must be a little longer than the scroll. A quick rule:

7 cm — interior doors and narrow frames.
10 cm — most front doors.
12–15 cm — wide entrances and statement cases.

If you are buying the case and scroll separately, check the case's inner length first. Buying them together avoids the guesswork.

3. Outdoors? Choose a sturdy case

A front-door mezuzah faces sun, rain and temperature swings. Choose a solid case that closes well, and wrap the scroll in a thin plastic sleeve so moisture cannot reach the ink.

4. How to hang it

Roll the scroll from the end toward the beginning, so the first word (Shema) is on the outside, and place it in the case.
Choose the doorpost on your right as you walk into the room.
Place it at the beginning of the upper third of the doorway height.
Ashkenazi custom slants the top toward the room; Sephardi custom hangs it upright.
Say the blessing: Baruch atah Adonai, Eloheinu melech ha'olam, asher kidshanu b'mitzvotav v'tzivanu likbo'a mezuzah — and fix it in place.

Every doorway of a living space gets a mezuzah (bathrooms and small closets do not). For questions about your specific home, ask your rabbi.

5. Keep it kosher

Ink can crack and letters can fade. The custom is to have home mezuzot checked twice every seven years, and any time a scroll has been exposed to water or damage.