What is my zip code?
A website cannot look up your ZIP code. It can ask for coordinates, and then ask a map database which postal area those coordinates fall in. Both steps happen only after you agree. On the edge of a ZIP boundary the answer can be the neighbouring code, because the lookup knows the point and not the address.
Your browser will ask before sharing anything. Nothing is uploaded.
Your zip code can be shown above once you allow location access. We take the precise coordinates your browser provides (only after you press the button and accept the prompt) and look them up with a public reverse-geocoding service, OpenStreetMap Nominatim, to find the postal code for that spot. We never see or store your coordinates ourselves.
A zip code, or postal code outside the United States, is a short code that groups nearby addresses for mail sorting and, increasingly, for online forms, delivery estimates, tax and shipping. It is a coarser locator than a full address, which is why it feels less invasive to share.
If you would rather not enable location, you can always find your zip code on a recent piece of mail, in your account settings on delivery sites, or by searching your street on a maps service. This page just makes it instant when you consent.
How a website reads this
This is the exact call a page makes. Nothing else is involved, and nothing is sent anywhere: the value is read in your browser and displayed to you.
navigator.geolocation.getCurrentPosition then a reverse geocodeTwo steps, and the first one asks. Coordinates come from the Geolocation API; turning them into a ZIP needs a lookup against a geocoding database, which here is OpenStreetMap Nominatim, reached through this site's own relay so the service gets the identification its usage policy requires.
- Needs your permission
- Yes, your browser asks first
- Can it be faked
- Yes. Follows the coordinates, so anything that overrides your location overrides this too.
- Contribution to a fingerprint
- Not counted. Not part of the fingerprint estimate: consent-gated. How we estimate this.
What a US ZIP code does and does not identify
ZIP codes were designed to route mail efficiently, not to describe places, and almost every misunderstanding about them follows from that.
| Form | What it covers | What it implies about you |
|---|---|---|
| Five digit ZIP | A delivery area, which can span a dense few blocks or a large rural district | Very little on its own in a city; more in a sparsely populated county |
| ZIP+4 | A specific block face, building or large recipient | A great deal. This is close to an address |
| Unique ZIP | A single high-volume recipient, such as one large organisation | That you are at that organisation |
| PO Box ZIP | A post office's box section, not a residential area | Where you collect mail, not where you live |
ZIP boundaries follow delivery routes rather than administrative borders, so they cross city and county lines routinely. A ZIP code is therefore a poor proxy for a municipality, which is exactly what a lot of software uses it as.
Why the answer can be the neighbouring code
The lookup takes a single point and asks a map database which postal area contains it. If your coordinates land within a hundred metres of a boundary, and the reading itself has an accuracy radius of a few dozen metres, the point can fall on the wrong side.
That is a limitation of doing it from coordinates rather than from an address. A form that asks you to type your ZIP code gets a better answer than any browser can, because you know which one is yours and the browser only knows where you are standing.
What you should know
Why sites collect it
Sites ask for a zip code to estimate shipping and delivery times, calculate tax, check service or store availability, and show local results. It is precise enough to be useful and coarse enough that people share it readily.
Privacy implications
A zip code narrows you to a neighbourhood, which is more revealing than a country but far less than a street address. Because this page reads your coordinates only after consent and sends them only to a public geocoding service (never to us), you control whether it is read at all.
How to change or hide it
Deny the location prompt to skip this entirely, or revoke access later in your browser settings. When you do share it with other sites, remember a zip code alone plus a birth date and gender can be surprisingly identifying, so give it only where it is genuinely needed.
Frequently asked questions
How do you find my zip code?
With your permission, your browser provides coordinates, which go to a public reverse-geocoding service (OpenStreetMap Nominatim) to look up the postal code. We never see or store them. Deny permission and nothing is read.
Can I find my zip code without sharing location?
Yes. Check recent mail, your saved addresses on shopping sites, or search your street on a map. This page is just the fastest option when you consent.
Sources
Browser behaviour changes and vendors cap these values differently, so the claims above that are not self-evident are checked against the specifications and vendor documentation below.
Last checked on . How these values are measured and estimated is set out on the methodology page.
Something wrong here? Tell us what your browser reports and it gets corrected.