Convert underscores into hyphens

This tool converts underscores into hyphens. It provides flexible options so you can convert every underscore, convert only those within specified substrings, convert all except allowed substrings, or replace underscores with a custom string. Simply enter your text and select the processing mode that suits your needs.

Input

Output

Processing Modes:

Convert All Underscores
Replaces every underscore (_) in the text with a hyphen (-).

Convert Only Specified Underscores
Only replaces underscores in the substrings you specify. Enter a comma‑separated list of exact substrings (e.g., "first_part, second_part").

Convert All Except Allowed Substrings
Replaces every underscore except those within the allowed substrings. Enter a comma‑separated list of substrings to preserve (e.g., "keep_this, do_not_change").

Replace Underscores with a Custom String
Replaces every underscore with a custom string. Enter the replacement text below.

Examples:

Convert All Underscores

Every underscore is replaced with a hyphen.

Before:

this_is_a_test

After:

this-is-a-test

Convert Only Specified Underscores

Only replaces underscores in the specified substrings.

Before:

first_part_middle second_part_end

After (specifying "first_part"):

first-part_middle second_part_end

Convert All Except Allowed Substrings

Replaces every underscore except those in the allowed substrings.

Before:

keep_this unchanged_and_change_this

After (allowing "keep_this"):

keep_this unchanged-and-change-this

Replace Underscores with Custom String

Every underscore is replaced with the custom string you provide.

Before:

convert_this_text

After (using custom string "->"):

convert->this->text