file extension

noun

A short series of text characters at the end of a computer filename, used to indicate the type of contents and the software that will be required to operate or open it.

“A text file may have a file extension of .txt.”

Similar
filename extensionextension
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Meanings

nounfile extension (plural file extensions)

plural file extensions

  1. A short series of text characters at the end of a computer filename, used to indicate the type of contents and the software that will be required to operate or open it.

    A text file may have a file extension of .txt.

    Synonyms: filename extension, extension

Synonyms & antonyms

nounA short series of text characters at the end of a computer filename, used to indicate the type of contents and the software that will be required to operate or open it.

Similar
filename extensionextension
Also see
filename extension

Translations

Chinese Cantonese 副檔名 /副档名
  • 副檔名 /副档名 (fu³ dong² ming⁴)string of characters
Chinese Mandarin 擴展名 /扩展名, 文件擴展名 /文件扩展名
  • 擴展名 /扩展名 (kuòzhǎnmíng)string of characters
  • 文件擴展名 /文件扩展名 (wénjiàn kuòzhǎnmíng)string of characters
  • 副檔名 /副档名 (fùdǎngmíng, fùdàngmíng)string of characters
  • 延伸檔名 /延伸档名 (yánshēn dǎngmíng, yánshēn dàngmíng)string of characters
  • 後綴名 /后缀名 (hòuzhuìmíng)string of characters
Czech koncovka souboru, přípona souboru
  • koncovka souborustring of characters
  • přípona souborustring of characters
Danish filtype, filendelse
  • filtypestring of characters
  • filendelsestring of characters
Dutch bestandsextensie
  • bestandsextensiestring of characters
Finnish tiedostopääte
  • tiedostopäätestring of characters
French extension de fichier
  • extension de fichierstring of characters
German Dateiendung
  • Dateiendungstring of characters
Greek επέκταση ονόματος αρχείου, επέκταση αρχείου
  • επέκταση ονόματος αρχείου (epéktasi onómatos archeíou)string of characters
  • επέκταση αρχείου (epéktasi archeíou)string of characters
Hungarian fájlkiterjesztés
  • fájlkiterjesztésstring of characters
Icelandic nafnauki
  • nafnaukistring of characters
Italian estensione di nome di schedario
  • estensione di nome di schedariostring of characters
Japanese 拡張子, ファイル拡張子
  • 拡張子 (kakuchōshi)string of characters
  • ファイル拡張子 (fairu-kakuchōshi)string of characters
Korean 확장자, 파일 확장자
  • 확장자 (hwakjangja)string of characters
  • 파일 확장자string of characters
  • 확장명 (hwakjangmyeong)string of characters
  • 파일 확장명string of characters
Norwegian Bokmål filetternavn, filendelse
  • filetternavnstring of characters
  • filendelsestring of characters
  • filnavnsuffiksstring of characters
Polish rozszerzenie nazwy pliku
  • rozszerzenie nazwy plikustring of characters
Portuguese extensão
  • extensãostring of characters
Russian дополне́ние к файлу
  • дополне́ние к файлу (dopolnénije k fajlu)string of characters
Spanish extensión de archivo
  • extensión de archivostring of characters
Swedish filändelse
  • filändelsestring of characters
Cite this entry
APA

file extension. (n.d.). In WatkinsX Dictionary. Retrieved November 4, 2026, from https://dictionary.watkinsx.com/word/file%20extension

MLA

“file extension.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/file%20extension. Accessed November 4, 2026.

Chicago

WatkinsX Dictionary, s.v. “file extension,” accessed November 4, 2026, https://dictionary.watkinsx.com/word/file%20extension.

Source: file extension on Wiktionary, CC BY-SA 4.0.