BEM to SCSS/LESS Converter

Convert flat BEM class names into clean, nested SCSS/LESS structure automatically.

Supports both standard BEM (double dash -- for modifiers) and single underscore _ for modifiers.

Installation

npm install -g bem-css-converter

Usage

bem-css-converter input.css

That's it! The tool reads the CSS file and outputs the nested SCSS to the output file.

You can also specify output filename:

bem-css-converter input.css [output.scss]

Supported BEM Patterns

• Blocks: .block
• Elements: .block__element
• Modifiers: .block--modifier or .block_modifier
• Element modifiers: .block__element--modifier or .block__element_modifier
• Pseudo-classes: .block:hover → &:hover
• Media queries: Nested inside blocks
• Nested selectors: .block img → img { ... }

Example

Input CSS:

.block {
  color: red;
}

.block--error {
  color: blue;
}

.block__element {
  font-size: 14px;
}

.block__element--error {
  font-weight: bold;
}

Output SCSS:

.block {
  color: red;
  &--error {
    color: blue;
  }

  &__element {
    font-size: 14px;
    &--error {
      font-weight: bold;
    }
  }
}

Example with media queries

Input CSS:

.order-item {
  box-sizing: border-box;
  padding: 20px 32px;
  display: grid;
  grid-template-columns: 80fr 119fr 20px;
  gap: 20px;
  border: none;
  text-decoration: none;
  cursor: pointer;
  transition: background-color 0.15s linear;
}

.order-item_error {
  background-color: red;
  opacity: 0.7;
}

.order-item:hover {
  background-color: rgba(29, 44, 64, 0.05);
}

.order-item > span {
  color: black;
}

@media (max-width: 1599px) {
  .order-item {
    grid-template-columns: 400fr 280fr 20px;
  }
}

@media (max-width: 639px) {
  .order-item {
    padding: 20px 16px;
  }
}

Output SCSS:

.order-item {
  box-sizing: border-box;
  padding: 20px 32px;
  display: grid;
  grid-template-columns: 80fr 119fr 20px;
  gap: 20px;
  border: none;
  text-decoration: none;
  cursor: pointer;
  transition: background-color 0.15s linear;
  &:hover {
    background-color: rgba(29, 44, 64, 0.05);
  }
  > span {
    color: black;
  }
  @media (max-width: 1599px) {
    grid-template-columns: 400fr 280fr 20px;
  }
  @media (max-width: 639px) {
    padding: 20px 16px;
  }
  &_error {
    background-color: red;
    opacity: 0.7;
  }
}

Motivation

I built this to speed up my workflow when converting legacy CSS into structured SCSS

Assumptions

• Selectors are simple BEM classes starting with .
• No complex selectors with multiple classes or combinators
• Declarations are standard CSS properties

GitHub repo

⭐ Give me a star on GitHub: https://github.com/psycholessdev/bem-to-scss

License

This project is licensed under the MIT License.
You're free to use, modify, and distribute the code, but please include attribution by keeping the original license text and a link to this repository.