utf8 is an R package for manipulating and printing UTF-8 text that fixes multiple bugs in R’s UTF-8 handling.


Stable version

utf8 is available on CRAN. To install the latest released version, run the following command in R:


Development version

To install the latest development version, run the following:




Validate character data and convert to UTF-8

Use as_utf8() to validate input text and convert to UTF-8 encoding. The function alerts you if the input text has the wrong declared encoding:

# second entry is encoded in latin-1, but declared as UTF-8
x <- c("fa\u00E7ile", "fa\xE7ile", "fa\xC3\xA7ile")
Encoding(x) <- c("UTF-8", "UTF-8", "bytes")
as_utf8(x) # fails
#> Error in as_utf8(x): entry 2 has wrong Encoding; marked as "UTF-8" but leading byte 0xE7 followed by invalid continuation byte (0x69) at position 4

# mark the correct encoding
Encoding(x[2]) <- "latin1"
as_utf8(x) # succeeds
#> [1] "façile" "façile" "façile"

Normalize data

Use utf8_normalize() to convert to Unicode composed normal form (NFC). Optionally apply compatibility maps for NFKC normal form or case-fold.

# three ways to encode an angstrom character
(angstrom <- c("\u00c5", "\u0041\u030a", "\u212b"))
#> [1] "Å" "Å" "Å"
utf8_normalize(angstrom) == "\u00c5"

# perform full Unicode case-folding
utf8_normalize("Größe", map_case = TRUE)
#> [1] "grösse"

# apply compatibility maps to NFKC normal form
# (example from https://twitter.com/aprilarcus/status/367557195186970624)
utf8_normalize("𝖸𝗈 𝐔𝐧𝐢𝐜𝐨𝐝𝐞 𝗅 𝗁𝖾𝗋𝖽 𝕌 𝗅𝗂𝗄𝖾 𝑡𝑦𝑝𝑒𝑓𝑎𝑐𝑒𝑠 𝗌𝗈 𝗐𝖾 𝗉𝗎𝗍 𝗌𝗈𝗆𝖾 𝚌𝚘𝚍𝚎𝚙𝚘𝚒𝚗𝚝𝚜 𝗂𝗇 𝗒𝗈𝗎𝗋 𝔖𝔲𝔭𝔭𝔩𝔢𝔪𝔢𝔫𝔱𝔞𝔯𝔶 𝔚𝔲𝔩𝔱𝔦𝔩𝔦𝔫𝔤𝔳𝔞𝔩 𝔓𝔩𝔞𝔫𝔢 𝗌𝗈 𝗒𝗈𝗎 𝖼𝖺𝗇 𝓮𝓷𝓬𝓸𝓭𝓮 𝕗𝕠𝕟𝕥𝕤 𝗂𝗇 𝗒𝗈𝗎𝗋 𝒇𝒐𝒏𝒕𝒔.",
               map_compat = TRUE)
#> [1] "Yo Unicode l herd U like typefaces so we put some codepoints in your Supplementary Wultilingval Plane so you can encode fonts in your fonts."


Cite utf8 with the following BibTeX entry:

  title = {utf8: Unicode Text Processing},
  author = {Patrick O. Perry},
  year = {2018},
  note = {R package version 1.1.4},
  url = {https://github.com/patperry/r-utf8},


The project maintainer welcomes contributions in the form of feature requests, bug reports, comments, unit tests, vignettes, or other code. If you’d like to contribute, either

  • fork the repository and submit a pull request

  • file an issue;

  • or contact the maintainer via e-mail.

This project is released with a Contributor Code of Conduct, and if you choose to contribute, you must adhere to its terms.