Stack Overflow
professional and enthusiast programmers
User
8.566.855
Votes
116.576.571
Comments
78.040.021
Questions
15.535.242
Answers
24.136.992
Solved Questions
8.298.597
Unsolved Questions
4.474.056

Server Fault

system and network administrators
User
359.090
Votes
1.764.811
Comments
1.065.250
Questions
259.138
Answers
428.997
Solved Questions
127.957
Unsolved Questions
56.762

Super User

computer enthusiasts and power users
User
625.073
Votes
2.929.111
Comments
1.734.261
Questions
373.722
Answers
554.063
Solved Questions
158.281
Unsolved Questions
120.712

Meta Stack Exchange

meta-discussion of the Stack Exchange family of Q&A websites
User
200.629
Votes
2.335.309
Comments
841.237
Questions
85.942
Answers
126.694
Solved Questions
41.156
Unsolved Questions
10.861

Web Applications

power users of web applications
User
114.167
Votes
253.152
Comments
80.614
Questions
24.014
Answers
34.563
Solved Questions
9.257
Unsolved Questions
3.989

Arqade

passionate videogamers on all platforms
User
120.031
Votes
1.187.017
Comments
402.579
Questions
82.133
Answers
137.042
Solved Questions
51.353
Unsolved Questions
5.871

Webmasters

pro webmasters
User
65.345
Votes
184.988
Comments
118.759
Questions
29.238
Answers
46.143
Solved Questions
12.943
Unsolved Questions
1.713

Seasoned Advice

professional and amateur chefs
User
42.360
Votes
296.317
Comments
113.543
Questions
18.846
Answers
46.442
Solved Questions
9.736
Unsolved Questions
544
Game Development
professional and independent game developers
User
87.531
Votes
394.796
Comments
234.949
Questions
41.980
Answers
65.343
Solved Questions
22.679
Unsolved Questions
5.765
Photography
professional, enthusiast and amateur photographers
User
47.793
Votes
318.771
Comments
143.846
Questions
20.889
Answers
51.407
Solved Questions
10.995
Unsolved Questions
623

Cross Validated

people interested in statistics, machine learning, data analysis, data mining, and data visualization
User
158.992
Votes
765.198
Comments
557.071
Questions
122.771
Answers
117.239
Solved Questions
38.339
Unsolved Questions
48.255
Mathematics
people studying math at any level and professionals in related fields
User
430.240
Votes
5.763.756
Comments
4.868.982
Questions
931.471
Answers
1.310.257
Solved Questions
491.457
Unsolved Questions
208.624
Home Improvement
contractors and serious DIYers
User
54.920
Votes
241.206
Comments
189.976
Questions
36.953
Answers
63.002
Solved Questions
13.601
Unsolved Questions
5.378

Geographic Information Systems

cartographers, geographers and GIS professionals
User
84.974
Votes
561.951
Comments
376.009
Questions
95.267
Answers
112.431
Solved Questions
37.470
Unsolved Questions
19.538

TeX - LaTeX

users of TeX, LaTeX, ConTeXt, and related typesetting systems
User
128.346
Votes
1.885.959
Comments
912.034
Questions
154.028
Answers
201.639
Solved Questions
93.932
Unsolved Questions
10.873
Ask Ubuntu
Ubuntu users and developers
User
559.533
Votes
2.367.960
Comments
1.406.147
Questions
288.305
Answers
373.022
Solved Questions
98.256
Unsolved Questions
94.750

Personal Finance & Money

people who want to be financially literate
User
47.274
Votes
333.138
Comments
137.117
Questions
21.550
Answers
41.433
Solved Questions
10.112
Unsolved Questions
1.426
English Language & Usage
linguists, etymologists, and serious English language enthusiasts
User
201.587
Votes
1.449.733
Comments
882.492
Questions
94.522
Answers
220.909
Solved Questions
47.030
Unsolved Questions
6.283

Stack Apps

apps, scripts, and development with the Stack Exchange API
User
34.224
Votes
24.620
Comments
12.214
Questions
2.382
Answers
2.358
Solved Questions
874
Unsolved Questions
915

User Experience

user experience researchers and experts
User
85.975
Votes
438.401
Comments
161.684
Questions
25.704
Answers
68.674
Solved Questions
12.930
Unsolved Questions
816
Unix & Linux
users of Linux, FreeBSD and other Un*x-like operating systems
User
250.227
Votes
1.375.785
Comments
671.248
Questions
138.132
Answers
207.392
Solved Questions
66.963
Unsolved Questions
32.486

WordPress Development

WordPress developers and administrators
User
105.849
Votes
347.057
Comments
387.384
Questions
86.371
Answers
109.147
Solved Questions
41.560
Unsolved Questions
24.426
Theoretical Computer Science
theoretical computer scientists and researchers in related fields
User
32.612
Votes
208.655
Comments
75.167
Questions
9.362
Answers
13.646
Solved Questions
4.351
Unsolved Questions
2.302
Ask Different
power users of Apple hardware and software
User
196.482
Votes
686.146
Comments
349.140
Questions
89.511
Answers
133.995
Solved Questions
34.183
Unsolved Questions
25.465
Role-playing Games
gamemasters and players of tabletop, paper-and-pencil role-playing games
User
30.376
Votes
797.252
Comments
163.709
Questions
26.838
Answers
64.645
Solved Questions
18.405
Unsolved Questions
82
Bicycles
people who build and repair bicycles, people who train cycling, or commute on bicycles
User
25.533
Votes
173.852
Comments
95.977
Questions
11.232
Answers
27.812
Solved Questions
5.902
Unsolved Questions
308

Software Engineering

professionals, academics, and students working within the systems development life cycle
User
247.746
Votes
2.004.553
Comments
711.912
Questions
48.739
Answers
146.774
Solved Questions
28.545
Unsolved Questions
2.724

Electrical Engineering

electronics and electrical engineering professionals, students, and enthusiasts
User
129.510
Votes
825.237
Comments
802.446
Questions
98.577
Answers
173.992
Solved Questions
50.061
Unsolved Questions
10.308
Android Enthusiasts
enthusiasts and power users of the Android operating system
User
161.380
Votes
294.075
Comments
209.676
Questions
47.384
Answers
57.646
Solved Questions
13.665
Unsolved Questions
19.896

Physics

active researchers, academics and students of physics
User
130.002
Votes
1.034.882
Comments
740.623
Questions
115.848
Answers
168.704
Solved Questions
49.258
Unsolved Questions
23.982

Information Security

information security professionals
User
134.325
Votes
776.934
Comments
294.080
Questions
45.463
Answers
84.281
Solved Questions
21.747
Unsolved Questions
3.632
Graphic Design
Graphic Design professionals, students, and enthusiasts
User
80.105
Votes
242.840
Comments
124.026
Questions
24.127
Answers
43.882
Solved Questions
10.979
Unsolved Questions
2.129

Database Administrators

database professionals who wish to improve their database skills and learn from others in the community
User
119.355
Votes
451.551
Comments
283.955
Questions
63.966
Answers
86.049
Solved Questions
30.771
Unsolved Questions
12.140
Science Fiction & Fantasy
science fiction and fantasy enthusiasts
User
71.872
Votes
1.485.278
Comments
418.526
Questions
47.239
Answers
90.901
Solved Questions
27.824
Unsolved Questions
3.279
Code Review
peer programmer code reviews
User
142.175
Votes
599.248
Comments
288.491
Questions
52.273
Answers
83.325
Solved Questions
30.242
Unsolved Questions
5.239
Programming Puzzles & Code Golf
programming puzzle enthusiasts and code golfers
User
61.014
Votes
741.486
Comments
290.461
Questions
9.470
Answers
118.329
Solved Questions
4.993
Unsolved Questions
87

Quantitative Finance

finance professionals and academics
User
21.089
Votes
78.012
Comments
44.427
Questions
10.531
Answers
13.998
Solved Questions
4.083
Unsolved Questions
2.477

Skeptics

scientific skepticism
User
30.448
Votes
343.059
Comments
126.079
Questions
8.469
Answers
10.602
Solved Questions
4.178
Unsolved Questions
1.107

Drupal Answers

Drupal developers and administrators
User
51.224
Votes
395.522
Comments
262.253
Questions
76.111
Answers
97.877
Solved Questions
34.518
Unsolved Questions
23.282

Motor Vehicle Maintenance & Repair

mechanics and DIY enthusiast owners of cars, trucks, and motorcycles
User
25.186
Votes
141.878
Comments
75.928
Questions
15.506
Answers
24.792
Solved Questions
6.014
Unsolved Questions
2.162

SharePoint

SharePoint enthusiasts
User
48.471
Votes
245.827
Comments
221.481
Questions
79.444
Answers
101.842
Solved Questions
31.296
Unsolved Questions
26.513
Music: Practice & Theory
musicians, students, and enthusiasts
User
32.577
Votes
199.482
Comments
87.769
Questions
12.970
Answers
34.445
Solved Questions
6.674
Unsolved Questions
345

Mi Yodeya

those who base their lives on Jewish law and tradition and anyone interested in learning more
User
9.566
Votes
290.850
Comments
212.005
Questions
25.015
Answers
39.838
Solved Questions
8.577
Unsolved Questions
3.768
Japanese Language
students, teachers, and linguists wanting to discuss the finer points of the Japanese language
User
17.185
Votes
186.573
Comments
70.987
Questions
15.471
Answers
24.489
Solved Questions
11.006
Unsolved Questions
150

Philosophy

those interested in the study of the fundamental nature of knowledge, reality, and existence
User
23.947
Votes
115.031
Comments
104.004
Questions
9.990
Answers
23.694
Solved Questions
3.807
Unsolved Questions
910

Travel

road warriors and seasoned travelers
User
51.927
Votes
571.869
Comments
212.169
Questions
28.653
Answers
47.600
Solved Questions
12.566
Unsolved Questions
309

Cryptography

software developers, mathematicians and others interested in cryptography
User
42.684
Votes
153.228
Comments
94.276
Questions
15.785
Answers
20.390
Solved Questions
7.983
Unsolved Questions
2.041
Signal Processing
practitioners of the art and science of signal, image and video processing
User
26.500
Votes
76.408
Comments
74.767
Questions
14.704
Answers
18.226
Solved Questions
6.371
Unsolved Questions
3.466

Christianity

committed Christians, experts in Christianity and those interested in learning more
User
20.156
Votes
218.113
Comments
122.609
Questions
9.945
Answers
23.239
Solved Questions
5.114
Unsolved Questions
265
Bitcoin
Bitcoin crypto-currency enthusiasts
User
56.481
Votes
140.795
Comments
66.526
Questions
20.233
Answers
27.068
Solved Questions
7.852
Unsolved Questions
3.834
Movies & TV
movie and tv enthusiasts
User
42.571
Votes
407.069
Comments
109.707
Questions
15.282
Answers
25.433
Solved Questions
9.345
Unsolved Questions
1.270

Biology

biology researchers, academics, and students
User
28.916
Votes
185.444
Comments
101.213
Questions
19.157
Answers
22.175
Solved Questions
8.622
Unsolved Questions
3.707
Mathematica
users of Wolfram Mathematica
User
37.921
Votes
645.360
Comments
366.763
Questions
50.628
Answers
74.324
Solved Questions
27.306
Unsolved Questions
5.823
Academia
academics and those enrolled in higher education
User
68.334
Votes
775.485
Comments
225.721
Questions
22.805
Answers
53.116
Solved Questions
10.089
Unsolved Questions
804
Computer Science
students, researchers and practitioners of computer science
User
68.515
Votes
210.424
Comments
145.263
Questions
24.557
Answers
29.511
Solved Questions
11.311
Unsolved Questions
4.597
The Workplace
members of the workforce navigating the professional setting
User
60.176
Votes
898.501
Comments
236.733
Questions
18.265
Answers
58.151
Solved Questions
9.036
Unsolved Questions
10
Chemistry
scientists, academics, teachers and students
User
39.290
Votes
264.095
Comments
130.803
Questions
25.784
Answers
30.056
Solved Questions
10.530
Unsolved Questions
4.683

Raspberry Pi

users and developers of hardware and software for Raspberry Pi
User
66.988
Votes
127.517
Comments
105.775
Questions
22.106
Answers
29.031
Solved Questions
7.907
Unsolved Questions
6.361
Salesforce
Salesforce administrators, implementation experts, developers and anybody in-between
User
38.030
Votes
329.526
Comments
277.902
Questions
74.905
Answers
88.221
Solved Questions
33.051
Unsolved Questions
21.368

ExpressionEngine® Answers

administrators, end users, developers and designers for ExpressionEngine® CMS
User
5.528
Votes
38.401
Comments
33.285
Questions
12.064
Answers
15.416
Solved Questions
5.757
Unsolved Questions
2.577
Anime & Manga
anime and manga fans
User
20.715
Votes
133.100
Comments
46.883
Questions
9.017
Answers
13.384
Solved Questions
4.953
Unsolved Questions
1.086

Magento

users of the Magento e-Commerce platform
User
46.485
Votes
261.426
Comments
263.149
Questions
72.265
Answers
84.793
Solved Questions
27.315
Unsolved Questions
25.654
English Language Learners
speakers of other languages learning English
User
54.602
Votes
370.906
Comments
258.865
Questions
48.623
Answers
79.595
Solved Questions
24.644
Unsolved Questions
4.013

Network Engineering

network engineers
User
33.886
Votes
67.093
Comments
70.350
Questions
10.406
Answers
16.000
Solved Questions
5.654
Unsolved Questions
1.097
Blender
people who use Blender to create 3D graphics, animations, or games
User
39.067
Votes
207.657
Comments
150.774
Questions
38.319
Answers
37.783
Solved Questions
15.735
Unsolved Questions
10.744
MathOverflow
professional mathematicians
User
78.190
Votes
1.567.090
Comments
608.171
Questions
90.588
Answers
130.653
Solved Questions
42.202
Unsolved Questions
22.544

Stack Overflow em Português

programadores profissionais e entusiastas
User
81.784
Votes
547.912
Comments
493.570
Questions
99.677
Answers
120.744
Solved Questions
51.504
Unsolved Questions
25.709

Aviation

aircraft pilots, mechanics, and enthusiasts
User
22.585
Votes
289.576
Comments
95.140
Questions
11.598
Answers
22.385
Solved Questions
6.740
Unsolved Questions
415
Software Recommendations
people seeking specific software recommendations
User
30.063
Votes
78.504
Comments
48.777
Questions
14.657
Answers
14.432
Solved Questions
3.185
Unsolved Questions
6.785

Arduino

developers of open-source hardware and software that is compatible with Arduino
User
33.735
Votes
64.074
Comments
86.826
Questions
14.398
Answers
20.210
Solved Questions
5.996
Unsolved Questions
2.778

Data Science

Data science professionals, Machine Learning specialists, and those interested in learning more about the field
User
37.900
Votes
50.762
Comments
26.818
Questions
8.793
Answers
10.465
Solved Questions
3.047
Unsolved Questions
2.670
Puzzling
those who create, solve, and study puzzles
User
34.588
Votes
376.825
Comments
151.913
Questions
11.822
Answers
32.367
Solved Questions
9.875
Unsolved Questions
65

Worldbuilding

writers/artists using science, geography and culture to construct imaginary worlds and settings
User
40.625
Votes
622.473
Comments
285.705
Questions
15.853
Answers
76.374
Solved Questions
8.687
Unsolved Questions
6

Emacs

those using, extending or developing Emacs
User
13.349
Votes
89.268
Comments
50.396
Questions
13.220
Answers
15.359
Solved Questions
6.950
Unsolved Questions
3.114
Stack Overflow на русском
программистов
User
113.896
Votes
766.870
Comments
1.009.485
Questions
203.712
Answers
241.425
Solved Questions
100.245
Unsolved Questions
50.604
Law
legal professionals, students, and others with experience or interest in law
User
12.356
Votes
53.129
Comments
39.281
Questions
8.705
Answers
10.753
Solved Questions
3.253
Unsolved Questions
1.535
Stack Overflow en español
programadores y profesionales de la informática
User
70.578
Votes
162.865
Comments
241.991
Questions
50.393
Answers
60.838
Solved Questions
22.402
Unsolved Questions
17.417

Ethereum

users of Ethereum, the decentralized application platform and smart contract enabled blockchain
User
31.804
Votes
86.039
Comments
43.574
Questions
16.599
Answers
17.699
Solved Questions
6.422
Unsolved Questions
5.025