U-21

SM U-21 - submarine. Article “U-21” in Spanish Wikipedia has 8.6 points for quality (as of July 1, 2025). The article contains 1 references and 4 sections.

This article has the best quality in Chinese Wikipedia. However, the most popular language version of this article is English.

Since the creation of article “U-21”, its content was written by 1 registered users of Spanish Wikipedia and edited by 186 registered Wikipedia users in all languages.

The article is cited 13 times in Spanish Wikipedia and cited 1237 times in all languages.

The highest Authors Interest rank from 2001:

• Local (Spanish): #43143 in June 2024
• Global: #44372 in August 2014

The highest popularity rank from 2008:

• Local (Spanish): #444572 in June 2024
• Global: #105094 in January 2018

There are 13 language versions for this article in the WikiRank database (of the considered 55 Wikipedia language editions).

The quality and popularity assessment was based on Wikipédia dumps from July 1, 2025 (including revision history and pageviews for previous years).

The table below shows the language versions of the article with the highest quality.

#	Language	Quality grade	Quality score
1	Chinese (zh) U-21号潜艇 (1913年)		66.179
2	English (en) SM U-21 (Germany)		58.5592
3	Turkish (tr) SM U-21		58.5371
4	German (de) U 21 (U-Boot, 1913)		49.5723
5	French (fr) Unterseeboot 21 (1913)		38.6736
6	Ukrainian (uk) SM U-21 (Кайзерліхе Маріне)		31.8742
7	Czech (cs) SM U 21		12.9445
8	Persian (fa) اس‌ام او-۲۱ (آلمان)		11.1903
9	Spanish (es) U-21		8.5769
10	Japanese (ja) U21 (ドイツ潜水艦・初代)		8.1385

More...

The following table shows the most popular language versions of the article.

The most popular language versions of the article "U-21" in all the time

#	Language	Popularity award	Relative popularity
1	English (en) SM U-21 (Germany)		332 154
2	German (de) U 21 (U-Boot, 1913)		136 356
3	Turkish (tr) SM U-21		20 215
4	French (fr) Unterseeboot 21 (1913)		5 063
5	Japanese (ja) U21 (ドイツ潜水艦・初代)		4 875
6	Chinese (zh) U-21号潜艇 (1913年)		4 640
7	Polish (pl) SM U-21 (1913)		4 323
8	Norwegian (no) «U 21»		3 780
9	Spanish (es) U-21		1 221
10	Persian (fa) اس‌ام او-۲۱ (آلمان)		1 187

More...

The following table shows the language versions of the article with the highest popularity in the last month.

The most popular language versions of the article "U-21" in June 2025

#	Language	Popularity award	Relative popularity
1	English (en) SM U-21 (Germany)		1 458
2	German (de) U 21 (U-Boot, 1913)		396
3	Turkish (tr) SM U-21		130
4	Chinese (zh) U-21号潜艇 (1913年)		117
5	Japanese (ja) U21 (ドイツ潜水艦・初代)		116
6	Spanish (es) U-21		99
7	Polish (pl) SM U-21 (1913)		82
8	Czech (cs) SM U 21		35
9	French (fr) Unterseeboot 21 (1913)		35
10	Norwegian (no) «U 21»		12

More...

The following table shows the language versions of the article with the highest Authors’ Interest.

Language versions of the article "U-21" with the highest Authors Interest (number of authors). Only registered Wikipedia users were taken into account.

#	Language	AI award	Relative AI
1	German (de) U 21 (U-Boot, 1913)		57
2	English (en) SM U-21 (Germany)		44
3	Norwegian (no) «U 21»		20
4	French (fr) Unterseeboot 21 (1913)		18
5	Polish (pl) SM U-21 (1913)		11
6	Turkish (tr) SM U-21		11
7	Ukrainian (uk) SM U-21 (Кайзерліхе Маріне)		8
8	Chinese (zh) U-21号潜艇 (1913年)		8
9	Japanese (ja) U21 (ドイツ潜水艦・初代)		3
10	Czech (cs) SM U 21		2

More...

The following table shows the language versions of the article with the highest Authors’ Interest in the last month.

Language versions of the article "U-21" with the highest AI in June 2025

#	Language	AI award	Relative AI
1	Arabic (ar) غواصة يو-21 (ألمانيا)		0
2	Czech (cs) SM U 21		0
3	German (de) U 21 (U-Boot, 1913)		0
4	English (en) SM U-21 (Germany)		0
5	Spanish (es) U-21		0
6	Persian (fa) اس‌ام او-۲۱ (آلمان)		0
7	French (fr) Unterseeboot 21 (1913)		0
8	Japanese (ja) U21 (ドイツ潜水艦・初代)		0
9	Norwegian (no) «U 21»		0
10	Polish (pl) SM U-21 (1913)		0

More...

The following table shows the language versions of the article with the highest number of citations.

Language versions of the article "U-21" with the highest Citation Index (CI)

#	Language	CI award	Relative CI
1	Chinese (zh) U-21号潜艇 (1913年)		414
2	Arabic (ar) غواصة يو-21 (ألمانيا)		306
3	English (en) SM U-21 (Germany)		229
4	German (de) U 21 (U-Boot, 1913)		170
5	French (fr) Unterseeboot 21 (1913)		32
6	Polish (pl) SM U-21 (1913)		21
7	Spanish (es) U-21		13
8	Persian (fa) اس‌ام او-۲۱ (آلمان)		13
9	Japanese (ja) U21 (ドイツ潜水艦・初代)		10
10	Ukrainian (uk) SM U-21 (Кайзерліхе Маріне)		10

More...

#	Language	Value
ar	Arabic غواصة يو-21 (ألمانيا)
cs	Czech SM U 21
de	German U 21 (U-Boot, 1913)
en	English SM U-21 (Germany)
es	Spanish U-21
fa	Persian اس‌ام او-۲۱ (آلمان)
fr	French Unterseeboot 21 (1913)
ja	Japanese U21 (ドイツ潜水艦・初代)
no	Norwegian «U 21»
pl	Polish SM U-21 (1913)
tr	Turkish SM U-21
uk	Ukrainian SM U-21 (Кайзерліхе Маріне)
zh	Chinese U-21号潜艇 (1913年)

Best Rank

Spanish: #444572 06.2024

Global: #105094 01.2018

Best Rank

Spanish: #43143 06.2024

Global: #44372 08.2014

On 16 March 2026 in multilingual Wikipedia, Internet users most often read articles on the following topics: 98th Academy Awards, Michael B. Jordan, Sinners, Jessie Buckley, Paul Thomas Anderson, Sean Penn, One Battle After Another, Amy Madigan, Hamnet, Timothée Chalamet.

In Spanish Wikipedia the most popular articles on that day were: 98.ª edición de los Premios Óscar, Una batalla tras otra, Michael B. Jordan, Marcelo Araujo, Paul Thomas Anderson, Amy Madigan, Jessie Buckley, Sean Penn, Sinners, Hamnet (película).

The WikiRank project is intended for automatic relative evaluation of the articles in the various language versions of Wikipedia. At the moment the service allows to compare over 44 million Wikipedia articles in 55 languages. Quality scores of articles are based on Wikipedia dumps from July, 2025. When calculating current popularity and AI of articles data from June 2025 was taken into account. For historical values of popularity and AI WikiRank used data from 2001 to 2025... More information