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String#end_with? 

str.end_with?(*suffixes) -> true or false
Returns Boolean· Updated May 14, 2026· String Methods
stringssuffixboolean

The end_with? method tests whether a string ends with a specified suffix. It takes one or more suffix arguments and returns true if the string terminates with any of them, otherwise false. This method is useful for validating file extensions, checking URL domains, and routing logic.

The match is exact and case-sensitive. There is no built-in option for case-insensitive matching — you must convert the string and suffix to the same case yourself if needed.

Syntax

str.end_with?(*suffixes)

The splat operator allows multiple suffixes. The method returns true if the string ends with any of the provided suffixes.

Parameters

ParameterTypeDefaultDescription
*suffixesString—One or more suffix strings to check. Pass each as a separate argument.

Examples

Basic usage

"ruby".end_with?("y")
# => true

"ruby".end_with?("r")
# => false

"ruby".end_with?("by")
# => true

Multiple suffixes

"report.pdf".end_with?("pdf", "doc", "txt")
# => true

"image.png".end_with?("jpg", "gif", "svg")
# => false

"data.csv".end_with?("csv", "xlsx")
# => true

Case sensitivity

"Ruby".end_with?("ruby")
# => false

"Ruby".end_with?("Ruby")
# => true

# Case-insensitive version:
"Ruby".downcase.end_with?("ruby")
# => true

Empty suffix

"hello".end_with?("")
# => true

"".end_with?("")
# => true

An empty suffix always matches because every string ends with an empty string.

No arguments

"hello".end_with?()
# => true

Called with no arguments, end_with? returns true (vacuous truth — every string ends with nothing).

Common Patterns

File extension checking

def pdf_file?(filename)
  filename.end_with?(".pdf")
end

def image_file?(filename)
  filename.end_with?(".png", ".jpg", ".gif", ".webp")
end

pdf_file?("document.pdf")    # => true
pdf_file?("document.PDF")    # => false (case-sensitive)
image_file?("photo.jpg")      # => true

URL and domain validation

def secure_url?(url)
  url.end_with?("https://")
end

def asset_path?(path)
  path.end_with?(".js", ".css", ".svg", ".png")
end

def markdown_file?(filename)
  filename.end_with?(".md", ".markdown")
end

Conditional routing

case filename
when ->(f) { f.end_with?(".rb") }
  run_ruby_file(filename)
when ->(f) { f.end_with?(".py") }
  run_python_file(filename)
when ->(f) { f.end_with?(".js") }
  run_javascript_file(filename)
else
  unknown_file_handler(filename)
end

Checking Against an Array of Suffixes

If you have an array of suffixes, you must splat it when passing to end_with?:

extensions = [".pdf", ".doc", ".txt"]

"report.pdf".end_with?(extensions)
# => false (passes the array as a single argument, which won't match)

"report.pdf".end_with?(*extensions)
# => true (splats the array into separate arguments)

Without the splat, Ruby compares the string against the array object itself, not its elements.

Gotchas

Regexp is not supported

Unlike start_with?, end_with? does not accept a Regexp argument. Passing a Regexp will raise an ArgumentError or match against the object’s string representation:

"ruby123".end_with?(/\d+/)
# => false (attempts to match against the Regexp object's to_s)

# Use gsub or match instead for regex suffix matching:
"ruby123".match?(/\d+\z/)
# => true

Order of suffixes does not matter

"ruby".end_with?("y", "by") behaves the same as "ruby".end_with?("by", "y") — either match returns true.

Case sensitivity is strict

There is no end_with?(:ignore_case) option. Always normalize case if you need case-insensitive matching.

Errors

Passing nil as a suffix raises a NoMethodError:

"hello".end_with?(nil)
# => NoMethodError: undefined method `end_with?' for nil:NilClass

Always ensure suffix values are strings before calling end_with?.

See Also