ZIP codes are such interesting identifiers. Their intended use was for facilitating more efficient mail sorting, they were not for providing any sort of human-friendly location data. Yet we still end up using them in so many parts of our lives for identity verification, navigation, population statistics, ...
They remind me of Social Security numbers in a way, where an identifier created for one narrow use (internal Social Security use only) ended up becoming a de facto standard (national identification number) due to the absense of a suitable alternative.
If you'd like to go further down the ZIP code rabbit hole, a few interesting codes to research are `00501`, `48222`, and `12345`. :)
For those that may be interested, this is my project to easily get a list of every zipcode + city/state combo. It is available as JSON you can easily directly work with, or even try a service like this: https://usps-zip-codes.deno.dev/90210.
I have a pet peeve for having to enter my zip code after I've already had to type in the city and state. There wasn't any easily downloadable file that had every ZIP code though. I keep hoping more sites will ask for ZIP first and then just auto fill it using data like this. /wishfulthinking
Nice find! Looks like something they recently added. Before I made this project I was looking for exactly something like that and I couldn't find it anywhere.
Thanks for the heads up on the newer https://postalpro.usps.com/ZIP_Locale_Detail file. I converted my script over to being a Python script that uses ZIP_Locale_Detail.xlsx as the source and doesn't require API access anymore.
My new file contains all of the ZIP + city/state combo from that file now.
I have a pet peeve for having to enter my zip code after I've already had to type in the city and state.
What else would you expect? Typing my zip is way easier than going through a list of zipcodes in a dropdown, many of which will be off by one digit in different spots. (ETA: I reread your comment and see what you are expecting)
I like the experience of autocomplete while I'm typing out my street address.
I think the sentiment for the pet peeve is commentary on the perceived inefficient sequence of the data input and a hope for reducing the number of fields entered from 3 to 1.
>I have a pet peeve for having to enter my zip code AFTER I've already had to type in the city and state.
The city and state can be derived from the zipcode - so why not simply ask for the zipcode to be typed and then auto-populate the associated city and state.
There are multiple zip codes in my state (Massachusetts) that cover multiple towns some examples include 01002 which is Pelham and much of Amherst, 01027 which is both Easthampton and Westhampton (different towns) etc.
Thanks for the heads up. It definitely used to include the 0xxxx ZIP codes. It is supposed to just naively fetch everything between 00000 and 99999 and record the USPS response. I'll have to re-run it and update it.
I'm in a zip code that spans two cities and I can think of other ways it gets complicated in different scenarios. There are places where I can throw a ball across multiple zip codes, sales tax jurisdictions, municipal lines, county lines, etc., with varying degrees of overlap.
The problem I've anecdotally seen with autocomplete is there's another property with the same street address as mine but in a different city and different zip code (granted only last digit is different IIRC) about ~15 miles away and on more than one occasion it's caused a few mix-ups.
I like the autocomplete too. Probably the best pattern, but it does usually do that by leveraging paid Google Maps APIs I believe.
I was frustrated that this seemingly open data wasn't openly available. Anything that asks for city+state+zipcode can ask for zip code first, auto populate the rest. For the edge cases where the city is wrong, the person can still type in the city like they would have needed to anyway.
It is worth noting that a package would never get delivered to the wrong place because the city wasn't correct but the ZIP code was. The USPS routes based on ZIP codes, not city/state.
i prefer my device to autofill data i've chosen to save for that purpose into a dumb form 99% of the time over the "start typing your address to locate..." functionality i see on checkout screens these days. maybe someday when they're faster/more transparent, sure, but for now the functionality you reference exists and is not great.
For what it is worth, this is the ZIP code data as according to the USPS. The scripts simply create the JSON file for you by calling the USPS API for every zip code between 00000 and 99999 (plenty of holes in there) and recording the response if there is one.
zip codes are not geographic areas, they are a collection of mail delivery points. Sometimes those points are not geographically contiguous or may overlap
This is a fact of ZIP Codes that a lot of people stumble one. I've worked on GIS/mapping projects in the past where stakeholders wanted or assumed ZIP Codes to be polygons.
Another complexity that surprises folks is you can't guarantee a one-to-many state-to-ZIP Code relationship. There are several (I forgot offhand how many, I used to have them memorized) that span across state boundaries.
Yep, this fact eluded me earlier in the year. I was supposed to map out all ZIP codes in the US and color their boundaries based on certain stats we had. We were surprised to find many areas in the US were empty because they didn't have ZIP codes. I did a quick search and found out ZIP codes are driven by mail routes, and that instantly made sense to me, but the product stakeholders were very surprised to learn it.
One thing I just recalled is that if you maintain a small exceptions lookup table (i.e. the ones that span state boundaries), you can use ZIP Codes as a way to uniquely look up a county name.
For example, health care plans in the US are county-specific with regard to premiums, co-pays, etc. (based on demographics). Allowing someone to type in their ZIP Code to get started can be a better user experience than having them pick their county.
My ZIP code happens to be shared by two separate cities and there are a few websites (Github, I'm looking at you) that will fail the payment, registration, etc. attempt if you don't enter the municipality that it THINKS is correct.
Exact opposite problem at my former rental: Two different properties with different ZIP codes... but they had the same address on the same road, just a mile apart (different jurisdictions).
I lived in a house; the other location was a nail spa. Strangers sometimes visited thinking they were at the right address (they weren't) to get their nails'did (they didn't).
A lot of this is on the people doing the platting in the first place. I would note, for example, that where I live in Oak Park, when they replatted the suburb after splitting from Austin Township with a different grid than is used in Chicago and the neighboring suburbs that
1. They kept the Chicago grid on the edge streets of the village so that, e.g., 110 North Austin would be across the street from 111 North Austin and
2. If they had kept the usual new 100 at each block system, the north-south streets on the south end would have been 1200–1249 which would have been identical to the numbers of the next block south in Berwyn and Cicero so the last block on the north-south streets is instead 1150–1199.
Contrast the borders of Los Angeles which in some areas are almost fractal in their complexity (there are buildings which straddle the boundary between L.A. and its neighbors and many blocks where adjacent buildings are in different cities). For whatever reason, the powers that be decided that the incompatible address numbering between adjacent cities should be retained so you will have weird discontinuities in building numbering along a block depending on what city the building lies in. I remember my wife having a doctor’s appointment in a building which was one of those which crossed the border so it had two different addresses assigned to it, one for Los Angeles and one for Beverly Hills.
A lot of P. O. Boxes have their own zip+4 address. You can spot these because the P.O. Box number and the +4 are usually the same (or occasionally the P.O. Box number is the last two digits of the five-digit zip code combined with the +4 so that a piece of mail with a box number and no zip code can be delivered to the correct post office in a large city).
The military postal code system is seperate from the US post office's zip code system. Often (and easily!) conflated but actually operating in parallel. Made even more confusing because many U.S. based entities can be reached in both systems.
zip codes are not geographic areas, they are a collection of mail delivery points.
Indeed. My zip is from a neighboring state but has a -xxxx to route specifically to my mail distribution center. Even without the last 4 digits they manage to figure it out, just slower.
The + button doesn't work on Firefox (143.0.1; Linux; flatpak; x86-64). The - button works and so do other ways of zooming in (scrolling, double click).
Even when I worked for Medicare I couldn't get the damned post office to give us accurate zip code data! It's terrible geodata but also almost everybody remembers it and most zip codes map to one county, so it was the best UI we found for getting a general area for where a person lived.
yeah! There are like 12 three-county zip codes, some are really fun, like places where a boat delivers the mail and goes to multiple states along the lake. And some zips don't refer to geographical areas at all, and others are military bases.
It was still the best UI option despite that - if you entered a ZIP that corresponded to multiple states/counties we'd pop up a second box that asked you which you lived in, but for 99% of people it was all we needed
This map lists Portsmouth, NH as having the zip code 00210 - 00215, which... aren't valid zip codes. It does also show Portsmouth with the correct zip of 03801 - 03804.
I wonder how that happened, and if there are any other weird errors?
Honestly this is exactly the outcome I had wanted when I started smacking in codes starting with 000, then 001, and 002 actually had a little blip stayed highlighted so I investigated further.
Going to date myself a bit here but way back in the day (early 2000's ish) we had to pay a LOT of money to get a zipcode database lol. Early ecomm and site builds sometimes needed em and man was the data rough.
This is cool but just took me down memory lane a bit.
I did not find this map very useful but interesting as a visual reference. Here is one with zip code boundaries on a map: https://www.unitedstateszipcodes.org/
To make this more than "this is just the xkcd population map joke" https://xkcd.com/1138/ , better title could be "Distribution Search of Zip Codes in the United States".
Point here is to type 0, 1, 2, etc. in the search box to see how zip codes with that prefix are geographically distributed.
I read an interesting story where this distribution comes from the manual mail sorting days... before computer sorting, postal workers could read the first digit and drop it into one of 10 boxes based on what part of the country it was going to, and so on for each additional digit.
Other countries have said "ah f it, it's all computers these days anyways, lets just make all addresses arbitrary random codes with no correlation between code distance and geographic distance. A database lookup at computer speed is a database lookup no matter what."
ZIP codes are such interesting identifiers. Their intended use was for facilitating more efficient mail sorting, they were not for providing any sort of human-friendly location data. Yet we still end up using them in so many parts of our lives for identity verification, navigation, population statistics, ...
They remind me of Social Security numbers in a way, where an identifier created for one narrow use (internal Social Security use only) ended up becoming a de facto standard (national identification number) due to the absense of a suitable alternative.
If you'd like to go further down the ZIP code rabbit hole, a few interesting codes to research are `00501`, `48222`, and `12345`. :)
I find it interesting that we use them to represent areas while they were only intended to represent routes...
And this relates to why there are some ZIP codes that are in multiple states.
10048
The classic 90210
For those that may be interested, this is my project to easily get a list of every zipcode + city/state combo. It is available as JSON you can easily directly work with, or even try a service like this: https://usps-zip-codes.deno.dev/90210.
I have a pet peeve for having to enter my zip code after I've already had to type in the city and state. There wasn't any easily downloadable file that had every ZIP code though. I keep hoping more sites will ask for ZIP first and then just auto fill it using data like this. /wishfulthinking
https://github.com/pseudosavant/usps-zip-codes
Someone who deals with this, reason you type in the Zip Code is its rudimentary checksum to make sure someone put in right information.
> There wasn't any easily downloadable file that had every ZIP code though
Post Service says what? https://postalpro.usps.com/ZIP_Locale_Detail (Heads up, it's Excel document)
Nice find! Looks like something they recently added. Before I made this project I was looking for exactly something like that and I couldn't find it anywhere.
That page has been there 2021.
I first made this script in 2017, so recent is a relative term I guess.
Thanks for the heads up on the newer https://postalpro.usps.com/ZIP_Locale_Detail file. I converted my script over to being a Python script that uses ZIP_Locale_Detail.xlsx as the source and doesn't require API access anymore.
My new file contains all of the ZIP + city/state combo from that file now.
I have a pet peeve for having to enter my zip code after I've already had to type in the city and state.
What else would you expect? Typing my zip is way easier than going through a list of zipcodes in a dropdown, many of which will be off by one digit in different spots. (ETA: I reread your comment and see what you are expecting)
I like the experience of autocomplete while I'm typing out my street address.
I think the sentiment for the pet peeve is commentary on the perceived inefficient sequence of the data input and a hope for reducing the number of fields entered from 3 to 1.
>I have a pet peeve for having to enter my zip code AFTER I've already had to type in the city and state.
The city and state can be derived from the zipcode - so why not simply ask for the zipcode to be typed and then auto-populate the associated city and state.
There are multiple zip codes in my state (Massachusetts) that cover multiple towns some examples include 01002 which is Pelham and much of Amherst, 01027 which is both Easthampton and Westhampton (different towns) etc.
Thanks for the heads up. It definitely used to include the 0xxxx ZIP codes. It is supposed to just naively fetch everything between 00000 and 99999 and record the USPS response. I'll have to re-run it and update it.
The city and state can be derived from the zipcode
A few comments here suggest this isn't true.
If you want to reduce input to one field, the autocomplete based on the street address that I brought up is the best experience I've come across.
I'm in a zip code that spans two cities and I can think of other ways it gets complicated in different scenarios. There are places where I can throw a ball across multiple zip codes, sales tax jurisdictions, municipal lines, county lines, etc., with varying degrees of overlap.
The problem I've anecdotally seen with autocomplete is there's another property with the same street address as mine but in a different city and different zip code (granted only last digit is different IIRC) about ~15 miles away and on more than one occasion it's caused a few mix-ups.
I like the autocomplete too. Probably the best pattern, but it does usually do that by leveraging paid Google Maps APIs I believe.
I was frustrated that this seemingly open data wasn't openly available. Anything that asks for city+state+zipcode can ask for zip code first, auto populate the rest. For the edge cases where the city is wrong, the person can still type in the city like they would have needed to anyway.
It is worth noting that a package would never get delivered to the wrong place because the city wasn't correct but the ZIP code was. The USPS routes based on ZIP codes, not city/state.
I'm a little confused by your peeve:
There are ZIP codes that represent more than one city (town) - and that cross state boundaries.
And there are cities (towns) that have more than one ZIP code.
Your list is very incomplete. It seems to be missing all zip codes with a leading zero.
i prefer my device to autofill data i've chosen to save for that purpose into a dumb form 99% of the time over the "start typing your address to locate..." functionality i see on checkout screens these days. maybe someday when they're faster/more transparent, sure, but for now the functionality you reference exists and is not great.
It doesn't contain my zipcode/city combination. My zip code spans across a city line, and the json file only has the OTHER city in it.
For what it is worth, this is the ZIP code data as according to the USPS. The scripts simply create the JSON file for you by calling the USPS API for every zip code between 00000 and 99999 (plenty of holes in there) and recording the response if there is one.
Thought it was going to be this (from 17 years ago):
- https://www.benfry.com/zipdecode/
- https://hw.leftium.com/#/item/446666
Of course, the results are pretty similar.
---
Another interesting ZIP code visualization: https://eagereyes.org/zipscribble-maps/united-states
zip codes are not geographic areas, they are a collection of mail delivery points. Sometimes those points are not geographically contiguous or may overlap
This is a fact of ZIP Codes that a lot of people stumble one. I've worked on GIS/mapping projects in the past where stakeholders wanted or assumed ZIP Codes to be polygons.
Another complexity that surprises folks is you can't guarantee a one-to-many state-to-ZIP Code relationship. There are several (I forgot offhand how many, I used to have them memorized) that span across state boundaries.
Yep, this fact eluded me earlier in the year. I was supposed to map out all ZIP codes in the US and color their boundaries based on certain stats we had. We were surprised to find many areas in the US were empty because they didn't have ZIP codes. I did a quick search and found out ZIP codes are driven by mail routes, and that instantly made sense to me, but the product stakeholders were very surprised to learn it.
One thing I just recalled is that if you maintain a small exceptions lookup table (i.e. the ones that span state boundaries), you can use ZIP Codes as a way to uniquely look up a county name.
ZIP codes also span county boundaries that aren't state boundaries -- I know of several in my county alone
Why would you do this?
For example, health care plans in the US are county-specific with regard to premiums, co-pays, etc. (based on demographics). Allowing someone to type in their ZIP Code to get started can be a better user experience than having them pick their county.
https://www.healthcare.gov/see-plans/
Except when it isn’t. I’d be curious to know the population in areas where a zip code spans multiple counties.
In that case, each county that corresponds to that ZIP Code is shown and the user can disambiguate manually.
My ZIP code happens to be shared by two separate cities and there are a few websites (Github, I'm looking at you) that will fail the payment, registration, etc. attempt if you don't enter the municipality that it THINKS is correct.
Exact opposite problem at my former rental: Two different properties with different ZIP codes... but they had the same address on the same road, just a mile apart (different jurisdictions).
I lived in a house; the other location was a nail spa. Strangers sometimes visited thinking they were at the right address (they weren't) to get their nails'did (they didn't).
A lot of this is on the people doing the platting in the first place. I would note, for example, that where I live in Oak Park, when they replatted the suburb after splitting from Austin Township with a different grid than is used in Chicago and the neighboring suburbs that
1. They kept the Chicago grid on the edge streets of the village so that, e.g., 110 North Austin would be across the street from 111 North Austin and
2. If they had kept the usual new 100 at each block system, the north-south streets on the south end would have been 1200–1249 which would have been identical to the numbers of the next block south in Berwyn and Cicero so the last block on the north-south streets is instead 1150–1199.
Contrast the borders of Los Angeles which in some areas are almost fractal in their complexity (there are buildings which straddle the boundary between L.A. and its neighbors and many blocks where adjacent buildings are in different cities). For whatever reason, the powers that be decided that the incompatible address numbering between adjacent cities should be retained so you will have weird discontinuities in building numbering along a block depending on what city the building lies in. I remember my wife having a doctor’s appointment in a building which was one of those which crossed the border so it had two different addresses assigned to it, one for Los Angeles and one for Beverly Hills.
> to get their nails'did (they didn't)
I'm thinking an opportunity was missed here.
Would ZIP+4 help here?
Yep, Zip + 4 is pretty pinpoint, generally it's no more than 20 residences and there is plenty of Zip + 4 that is single address.
A lot of P. O. Boxes have their own zip+4 address. You can spot these because the P.O. Box number and the +4 are usually the same (or occasionally the P.O. Box number is the last two digits of the five-digit zip code combined with the +4 so that a piece of mail with a box number and no zip code can be delivered to the correct post office in a large city).
Yea, PO Boxes generally have their own Zip Code so they use +4 for that.
However, if you look at zip+4 for dwellings, it’s still few. My cul de sac with 5 houses has zip + 4 different from house on connecting street.
ZCTA[0] can (roughly) be used for this purpose
https://www.census.gov/programs-surveys/geography/guidance/g...
Related:
Stop Using Zip Codes for Geospatial Analysis (2019) - 184 points, 131 comments - https://news.ycombinator.com/item?id=42974728
Sometimes they're entire non geographic entities like the IRS
Or moving areas like aircraft carriers.
The military postal code system is seperate from the US post office's zip code system. Often (and easily!) conflated but actually operating in parallel. Made even more confusing because many U.S. based entities can be reached in both systems.
zip codes are not geographic areas, they are a collection of mail delivery points.
Indeed. My zip is from a neighboring state but has a -xxxx to route specifically to my mail distribution center. Even without the last 4 digits they manage to figure it out, just slower.
If you find this interesting and you haven't watched it, Go watch "The hidden pattern in post codes" [1]
[1] https://www.youtube.com/watch?v=1K5oDtVAYzk
The + button doesn't work on Firefox (143.0.1; Linux; flatpak; x86-64). The - button works and so do other ways of zooming in (scrolling, double click).
link to the zip code data is broken too; https://public.opendatasoft.com/explore/assets/us-zip-code-l... 404s
Even when I worked for Medicare I couldn't get the damned post office to give us accurate zip code data! It's terrible geodata but also almost everybody remembers it and most zip codes map to one county, so it was the best UI we found for getting a general area for where a person lived.
Except when it doesn't. 60447 is in three counties in Illinois. Which causes confusion when laws/regulations are applied at a county level.
yeah! There are like 12 three-county zip codes, some are really fun, like places where a boat delivers the mail and goes to multiple states along the lake. And some zips don't refer to geographical areas at all, and others are military bases.
It was still the best UI option despite that - if you entered a ZIP that corresponded to multiple states/counties we'd pop up a second box that asked you which you lived in, but for 99% of people it was all we needed
broken in mobile safari as well.
This map lists Portsmouth, NH as having the zip code 00210 - 00215, which... aren't valid zip codes. It does also show Portsmouth with the correct zip of 03801 - 03804. I wonder how that happened, and if there are any other weird errors? Honestly this is exactly the outcome I had wanted when I started smacking in codes starting with 000, then 001, and 002 actually had a little blip stayed highlighted so I investigated further.
This just places a dot on top of the centroid(?) of the zip code. Would be better with a shaded area for each zip.
Still cool!
As noted elsewhere in the discussion, not all zip codes are polygons. Some are lines or points.
You can get that on Google Maps by searching for [XXXXX zip code].
Going to date myself a bit here but way back in the day (early 2000's ish) we had to pay a LOT of money to get a zipcode database lol. Early ecomm and site builds sometimes needed em and man was the data rough. This is cool but just took me down memory lane a bit.
I did not find this map very useful but interesting as a visual reference. Here is one with zip code boundaries on a map: https://www.unitedstateszipcodes.org/
There are more beautiful ones:
https://www.printmag.com/designer-interviews/paula-scher-map...
This is so cool! Clicking 0 - 9 one by one, we can see how the zip codes traverse from extreme north-east to the west.
Fab visualization.
To make this more than "this is just the xkcd population map joke" https://xkcd.com/1138/ , better title could be "Distribution Search of Zip Codes in the United States".
Point here is to type 0, 1, 2, etc. in the search box to see how zip codes with that prefix are geographically distributed.
I read an interesting story where this distribution comes from the manual mail sorting days... before computer sorting, postal workers could read the first digit and drop it into one of 10 boxes based on what part of the country it was going to, and so on for each additional digit.
Other countries have said "ah f it, it's all computers these days anyways, lets just make all addresses arbitrary random codes with no correlation between code distance and geographic distance. A database lookup at computer speed is a database lookup no matter what."
This map is a neat visualization but is incomplete so far as there are some missing jurisdictions. Puerto Rico and the Virgin Islands, for example.
It would be nice if the usps would get out of mail delivery and focus on email. Wouldn’t mind a usps email account
you've seen this old article, right? https://www.bloomberg.com/features/2016-usps-email/
as the son of a (former) mailman, i would have loved an @usps.com email
Interesting (and also somewhat expected) that it acts as a fairly accurate proxy for population density.
The Canal Zone never had a zip code.
Why not, seeing how it was under US control long enough to get one?
heh Melber, KY
nice