Convert Strings into any Case

A consistent, flexible and easy to use tool to parse and convert strings into cases like snake or camel among others.


snakecase 0.9.2

  • cases: added to_sentence_case() (same as snake, but first letter is uppercase and default sep_out is space).
  • numerals: added numerals argument to all caseconverters including to_any_case() to format the alignment of digits (middle, left,right, asis). Therefore parsing_option nr 4 might be removed in later releases, as it is the same as parsing_option = 1 and numerals = "asis".
  • transliterations: When named character elements are supplied as part of transliterations, anyting that mateches the name is replaced by the corresponding value.
  • attributes are now preserved (not only names as before)

snakecase 0.9.1

  • CRAN release
  • Change default sep_in from NULL to "[^[:alnum:]]". This will make it easier for beginners and in general also faster to modify cases from names like names(iris). Updated the regarding sections in the vignette and readme.

snakecase 0.9.0

  • CRAN release

  • Changes since last update:

    • parsing_options:
      • old parsing_options 3 and 4 are replaced now by new
        • parsing_option 3, which suppresses case conversion around alpha numerics
        • parsing_option 4, which introduces less formatting of numerals in the output, and leaves them very close to the way that they appeared in the input strings.
    • abbreviations:
      • they work now more consistent with cases like lower- and upper camel case
    • new converters:
      • to_swap_case() is new. Within to_any_case() this conversion can be called also via case = "flip".
    • removed deprecated arguments
      • replace_special_characters, which is now called transliterations
      • preprocess, which is now called sep_in
      • postprocess, which is now called sep_out
    • removed dependencies:
      • purrr and magrittr are not longer dependencies
      • stringr is the only dependency now (including stringi of course).

snakecase 0.8.4

  • Introduced to_swap_case(), which is also available in to_any_case() via case = "swap" or case = "flip"


  • abbreviations work now also in conversions to lower- and upper camel case.

snakecase 0.8.3

  • replaced parsing_options 3 and 4 with 5 and 6.
  • removed purrr dependency
  • removed magrittr dependency


  • remove replace_special_characters, preprocess and postprocess.


  • added parsing option 6, which doesn't surround digits with separators.

snakecase 0.8.1

  • CRAN releases


  • some breaking changes:
    • reordering of the arguments of all to_xxx_case() functions
    • renaming preprocess to sep_in, postprocess to sep_out, replace_special_characters to transliterations.

snakecase 0.7.1

  • CRAN update

  • for changes see V 0.7.0

  • additionally fixed obvious bug and forwarded to_xxx_case args to to_any_case

snakecase 0.7.0

  • changes since last CRAN submission include:
    • to_xxx_case shortcuts are now exact wrappers around to_any_case
    • process is deprecated after changing implementation and setting a reasonable default.
    • added abbreviations argument to any_case()
    • case none is now a lot more general for formatting
    • added abbreviation specific behaviour for mixed case
    • new parsing_option 5, which suppresses conversion after ., @, etc
    • renaming of:
      • to_small / to_big_camel_case have been renamed to to_lower / to_upper_camel_case. The old names are and will still be supported in to_any_case
      • parsingoption to parsing_option
    • introduced rule that parsing_option <= 0 suppresses parsing from now on
    • lots of additional tests and smaller bugfixes
    • several documentation updates including help, examples, readme and vignette


  • all to_xxx_case functions are now exact wrappers of to_any_case
  • to_small / to_big_camel_case have been renamed to to_lower / to_upper_camel_case
  • minimal vignette update


  • more consistency for case none
  • bugfix for parsing option 5


  • overhaul readme
  • renamed parsingoption argument to parsing_option
  • process argument: changed implementation in to_any_case, set a reasonable default, implemented the behaviour also in to_xxx shortcut functions, deprecated process argument
  • make modifications to case none, which allows now more parsing options


  • added special behaviour for abbreviations within "mixed_case"


  • added abbreviations argument for better mixed case handling


  • improve consistency with stringr pkg regarding special input handling

    if(identical(stringr::str_length(string), integer())){return(character())}

snakecase 0.5.1

  • Changes since last update:
    • to_any_case() and shortcuts (to_xxx_case() functions) preserve name attribute now
    • R dependency lowered to 3.1


  • to_any_case() and the other converter function now preserve the names attribute. (Thanks to @strengejacke)

snakecase 0.5.0

  • CRAN update

  • Changes since last CRAN submission include:

    • string transliteration via updated replace_special_character argument
    • some new cases: "none", "mixed", "upper_lower", "lower_upper"
    • aliases: "all_caps", "lower_camel", "upper_camel"
    • different parsing options
    • several bugfixes
    • improved internal testing
    • internal modularisation


  • case == "none" works now with preprocess.


  • fixed bug so that case = upper_lower no also works for NA's.


  • added shortcutfunctions to_mixed_case(), to_lower_upper_case() and to_upper_lower_case().


Implemented two further parsing options:

  • 3: parses the first UPPER letter group like parsing option 2 and the rest like option 1
  • 4: parses the first UPPERlowercase letter group like parsingoption 1 and the rest like option 2


bug fix in devversion: protect works now for beginning and end of substrings and not anymore only for complete substrings.


Fix bug for character(0) in combination with postprocess


Input of replace special character is now a character vector. It's entries have to be elements of stringi::stri_trans_list() or names of the transliteration dictionary list, which comes with this package. This update enables users to transliterate strings from different encodings, in a flexible way. For example UTF8 to Ascii, ... .


  • provided aliases "all_caps", "lower_camel" and "upper_camel" for "screaming_snake", "small_camel" and "big_camel".


  • small bug fix for upper_lower/lower_upper regarding the behaviour for the combination of preprocess and protect (similar to an earlier bug in the camel cases).


  • small bug fix for behaviour of upper_lower/lower_upper. Now substrings with without alphabetical characters are ignored.


  • new implemented cases: "none", "mixed", "upper_lower", "lower_upper".


  • empty_fill runs again in the end, before the pre and postprocess
  • fixed bug: to_any_case("r.aStudio", protect = "a", postprocess = "-", case = "big_camel") will now correctly return "R-.AStudio" (so the protection will be triggered by the input and not by the output). In contrast protect = A will yield in unprotected output (-A-)


  • empty_fill runs now at the beginning of to any case function (after the first parsing) and a second parsing is introduced in case anything is filled.


  • fixed bug in camelcases, for letters after protected symbols (usually one wouldn't protect in these cases anyway...)


  • implemented check_design_rule() (not exported)
  • resolved bugs in other design options (also deleted one which is not valid for screaming snake case)


  • included several parsingoptions for to_any_case().
    1: "RRRStudio" -> "RRR_Studio" stays as default
    2: "RRRStudio -> RRRS_tudio"
    any other number will suppress the parsing (only spaces will be converted into "_")


  • This is the (stable) development version now. You can find snakecase on cran here

snakecase 0.4.0

  • CRAN submission


  • changed order of the customizing arguments of to_any_case()


  • fixed bug for combination of protect and postprocess. Therefore clarified and rewrote the internal order of to_any_case()
  • resolved all internal build warnings and notes


  • fixed bug in replace_special_characters combined with screaming snake case.

snakecase 0.3.5

  • any local special characters are now supported.
  • added 2 arguments to to_any_case(): empty_fill, which allows to fill strings matching to "" with the supplied string. unique_sep adds an integer suffix separated with the supplied string, when not NULL.
  • fixed a bug in to_snake_case_internal(). groups of digits are not separated in between anymore.
  • digits that are not direct next to each other, will be split via "_" in both camel case versions. This is a meaningful exception. Otherwise information would be lost and also the consistency rules in the readme wouldn't hold in this case.

snakecase 0.3.4

  • any_case() is now vectorised over pre-/postprocess, pre-/postfix for all case arguments
  • introduces protect as (vectorised) argument to to_any_case(). it accepts regular expressions and cleans "_" or whatever the preprocessing did, between matches.
  • some more tests, documentation and fixes.

snakecase 0.3.3

  • introduced case = "parsed" in to_any_case()
  • introduced to_parsed_case()

snakecase 0.3.2

  • finished vignette (title: Caseconverters) and replaced the usage part in readme with it.
  • changed behaviour in snake_case_internal to always treat whitespaces as underscores. for whitespaces in output postprocess = " " is recommended.

snakecase 0.3.1

  • started testing to_any_case and removed a bug.
  • added vignette

snakecase 0.3.0

  • supports behaviour for german umlauts on all platforms
  • introduced internal function to_snake_case_internal() which does the preprocessing and simplifies all other functions (especially to_any_case()) a little bit.
  • introduced to_screaming_snake_case()
  • added arguments prefix, postfix and replace_special_characters to to_any_case().
  • completely renewed readme
  • updated tests and highly modularized all tests. (just to_any_case lacks some tests now and in general more examples testcases have to be written)

snakecase 0.2.2

  • introduced to_any_case() (all functionality and documentation provided, but implementation has to be cleaned and also tests have to be written)

snakecase 0.2.1

  • fixed bug: to_snake_case_dev(c("ssRRss")) returns now ss_r_rss instead of"ss_r_r_ss"
  • to_snake_case() now treats only spaces like underscores now (not dots anymore)
  • functionality to treat different stuff like dots will be added via a new function:
    to_any_case(), which will wrap the other three and will have pre- and postprocess arguments

snakecase 0.2.0

  • renamed the single input parameters consistent to string (without deprecating the old name before, since the package was in early dev-stage anyway).
  • started a to develop and implement consistent logic (which still has to be better documented in the readme)
  • introduced tests for more hard coded examples and the logic behind it (still more hardcoded examples and a third part of the logic have to be tested)
  • internal logic has been simplified and modularised a lot, which makes it easier to maintain and introduce more highlevel features in the future
  • added integrated tests via appveyor on windows
  • added badges for cran status and codecoverage to readme

snakecase 0.1.0

  • Introduced to_snake_case() which converts strings to snake_case.
  • added functions to_small_camel_case() and to_big_camel_case() which internally build up on to_snake_case() and convert to the appropriate target case.
  • added basic hard coded tests
  • added integrated tests on linux via

Reference manual

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0.9.2 by Malte Grosser, 6 months ago

Report a bug at

Browse source code at

Authors: Malte Grosser [aut, cre]

Documentation:   PDF Manual  

GPL-3 license

Imports stringr, stringi

Suggests testthat, covr, tibble, purrrlyr, knitr, rmarkdown

Imported by facerec, janitor, parlitools, sjlabelled.

See at CRAN