I-21

Japanese submarine I-21 - 1940 Type B1 submarine. Article “I-21” in Spanish Wikipedia has 11.6 points for quality (as of July 1, 2025). The article contains 1 references and 6 sections.

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

Since the creation of article “I-21”, its content was written by 5 registered users of Spanish Wikipedia and edited by 129 registered Wikipedia users in all languages.

The article is cited 25 times in Spanish Wikipedia and cited 808 times in all languages.

The highest Authors Interest rank from 2001:

• Local (Spanish): #42089 in September 2017
• Global: #83942 in June 2012

The highest popularity rank from 2008:

• Local (Spanish): #426862 in August 2010
• Global: #257891 in August 2010

There are 9 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	Vietnamese (vi) I-21 (tàu ngầm Nhật)		60.0373
2	English (en) Japanese submarine I-21		47.1205
3	Russian (ru) I-21 (подводная лодка)		42.0017
4	French (fr) I-21 (sous-marin)		32.144
5	Ukrainian (uk) I-21		24.4677
6	Chinese (zh) 伊號第二十一潛艦		17.5707
7	Japanese (ja) 伊号第二十一潜水艦		12.2624
8	Spanish (es) I-21		11.6345
9	Persian (fa) زیردریایی آی-۲۱ (۱۹۴۰)		1.2057

More...

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

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

#	Language	Popularity award	Relative popularity
1	English (en) Japanese submarine I-21		125 478
2	Japanese (ja) 伊号第二十一潜水艦		92 344
3	Chinese (zh) 伊號第二十一潛艦		7 405
4	Spanish (es) I-21		5 744
5	Russian (ru) I-21 (подводная лодка)		4 225
6	French (fr) I-21 (sous-marin)		3 027
7	Persian (fa) زیردریایی آی-۲۱ (۱۹۴۰)		464
8	Ukrainian (uk) I-21		346
9	Vietnamese (vi) I-21 (tàu ngầm Nhật)		154

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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 "I-21" in June 2025

#	Language	Popularity award	Relative popularity
1	English (en) Japanese submarine I-21		906
2	Japanese (ja) 伊号第二十一潜水艦		276
3	Chinese (zh) 伊號第二十一潛艦		88
4	Russian (ru) I-21 (подводная лодка)		32
5	Spanish (es) I-21		23
6	Ukrainian (uk) I-21		12
7	Persian (fa) زیردریایی آی-۲۱ (۱۹۴۰)		10
8	French (fr) I-21 (sous-marin)		9
9	Vietnamese (vi) I-21 (tàu ngầm Nhật)		9

More...

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

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

#	Language	AI award	Relative AI
1	English (en) Japanese submarine I-21		66
2	Japanese (ja) 伊号第二十一潜水艦		19
3	French (fr) I-21 (sous-marin)		17
4	Chinese (zh) 伊號第二十一潛艦		9
5	Ukrainian (uk) I-21		7
6	Spanish (es) I-21		5
7	Russian (ru) I-21 (подводная лодка)		3
8	Vietnamese (vi) I-21 (tàu ngầm Nhật)		2
9	Persian (fa) زیردریایی آی-۲۱ (۱۹۴۰)		1

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 "I-21" with the highest AI in June 2025

#	Language	AI award	Relative AI
1	Ukrainian (uk) I-21		1
2	English (en) Japanese submarine I-21		0
3	Spanish (es) I-21		0
4	Persian (fa) زیردریایی آی-۲۱ (۱۹۴۰)		0
5	French (fr) I-21 (sous-marin)		0
6	Japanese (ja) 伊号第二十一潜水艦		0
7	Russian (ru) I-21 (подводная лодка)		0
8	Vietnamese (vi) I-21 (tàu ngầm Nhật)		0
9	Chinese (zh) 伊號第二十一潛艦		0

More...

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

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

#	Language	CI award	Relative CI
1	Ukrainian (uk) I-21		299
2	English (en) Japanese submarine I-21		175
3	Japanese (ja) 伊号第二十一潜水艦		109
4	Chinese (zh) 伊號第二十一潛艦		58
5	French (fr) I-21 (sous-marin)		48
6	Vietnamese (vi) I-21 (tàu ngầm Nhật)		45
7	Persian (fa) زیردریایی آی-۲۱ (۱۹۴۰)		28
8	Spanish (es) I-21		25
9	Russian (ru) I-21 (подводная лодка)		21

More...

#	Language	Value
en	English Japanese submarine I-21
es	Spanish I-21
fa	Persian زیردریایی آی-۲۱ (۱۹۴۰)
fr	French I-21 (sous-marin)
ja	Japanese 伊号第二十一潜水艦
ru	Russian I-21 (подводная лодка)
uk	Ukrainian I-21
vi	Vietnamese I-21 (tàu ngầm Nhật)
zh	Chinese 伊號第二十一潛艦

Best Rank

Spanish: #426862 08.2010

Global: #257891 08.2010

Best Rank

Spanish: #42089 09.2017

Global: #83942 06.2012

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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