Every ZIP code in the United States, with weather, radar, trivia and the numbers behind it. Five digits since 1963!

ZIP stands for Zone Improvement Plan. The codes went live on July 1, 1963.The lowest ZIP code is 00501 — the IRS in Holtsville, New York.The highest ZIP code is 99950, in Ketchikan, Alaska.Type 07734 into a calculator and turn it upside down: hELLO. It is Keansburg, New Jersey.12345 belongs to one company: General Electric in Schenectady, New York.The first digit is a region: 0 is New England and New Jersey, 9 is the West Coast, Alaska and Hawaii.Mr. ZIP, the cartoon mailman, was the mascot that sold the idea to America.ZIP+4 arrived in 1983 and can narrow a ZIP down to one side of one block.A ZIP code is a mail route, not a place: plenty of them cross county and even state lines.Play ZIP Hunt: guess the secret ZIP code of the day in six tries.
zipcodes.pro — RANKINGS/AL/HIGHEST-DENSITY

Most Densely Populated ZIP Codes in Alabama

What this measures. People per square mile of land area. Source: Census American Community Survey and Gazetteer, data release 2026-10-12.

# ZIP City County People per sq mi
1 36503 Atmore Escambia 29,471
2 35254 Birmingham Jefferson 17,147
3 35487 Tuscaloosa Tuscaloosa 16,116
4 35632 Florence Lauderdale 13,318
5 35229 Birmingham Jefferson 10,697
6 36101 Montgomery Montgomery 8,500
7 36849 Auburn University Lee 7,073
8 35205 Birmingham Jefferson 5,054
9 35013 Allgood Blount 5,036
10 35036 Brookside Jefferson 3,714
11 35208 Birmingham Jefferson 3,651
12 36609 Mobile Mobile 3,555
13 35209 Birmingham Jefferson 3,413
14 36604 Mobile Mobile 3,401
15 36663 Mobile Mobile 3,224
16 35816 Huntsville Madison 3,148
17 36082 Troy Pike 2,802
18 36111 Montgomery Montgomery 2,783
19 35064 Fairfield Jefferson 2,746
20 36606 Mobile Mobile 2,735
21 35218 Birmingham Jefferson 2,646
22 35216 Birmingham Jefferson 2,643
23 36688 Mobile Mobile 2,542
24 35181 Watson Jefferson 2,513
25 36107 Montgomery Montgomery 2,510
26 35213 Birmingham Jefferson 2,469
27 36617 Mobile Mobile 2,456
28 35233 Birmingham Jefferson 2,344
29 35228 Birmingham Jefferson 2,340
30 36106 Montgomery Montgomery 2,272
31 35805 Huntsville Madison 2,269
32 36115 Montgomery Montgomery 2,233
33 35226 Birmingham Jefferson 2,181
34 35222 Birmingham Jefferson 2,146
35 36109 Montgomery Montgomery 2,081
36 36603 Mobile Mobile 2,034
37 35758 Madison Madison 1,847
38 36867 Phenix City Russell 1,816
39 36607 Mobile Mobile 1,791
40 35204 Birmingham Jefferson 1,780
41 35203 Birmingham Jefferson 1,691
42 35801 Huntsville Madison 1,687
43 35249 Birmingham Jefferson 1,667
44 35212 Birmingham Jefferson 1,641
45 35244 Birmingham Shelby 1,602
46 35032 Bon Air Talladega 1,597
47 35757 Madison Madison 1,589
48 36652 Mobile Mobile 1,559
49 35206 Birmingham Jefferson 1,554
50 35215 Birmingham Jefferson 1,553

Showing the top 50 of 656 ZIP codes in Alabama that have this figure . 36503 ranks 1st at 29,471, against 1,553 in 50th place.

Other rankings for Alabama

Cite this page

zipcodes.pro. “Most Densely Populated ZIP Codes in Alabama.” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/rankings/al/highest-density

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