# L1 regularization

> A type of regularization that penalizes weights in proportion to the sum of the absolute value of the weights. L1 regularization helps drive the weights of irrelevant or barely relevant features to *exactly 0*. A feature with a weight of 0 is effectively removed from the model.[^1]

A type of [regularization](https://wiki.g15e.com/pages/Regularization%20(machine%20learning.txt)) that penalizes [weights](https://wiki.g15e.com/pages/Weight%20(machine%20learning.txt)) in proportion to the sum of the absolute value of the weights. L1 regularization helps drive the weights of irrelevant or barely relevant features to *exactly 0*. A [feature](https://wiki.g15e.com/pages/Feature%20(machine%20learning.txt)) with a weight of 0 is effectively removed from the [model](https://wiki.g15e.com/pages/Model%20(machine%20learning.txt)).[^1]

## See also

- [L2 regularization](https://wiki.g15e.com/pages/L2%20regularization.txt)

## Footnotes

[^1]: https://developers.google.com/machine-learning/glossary#L1_regularization