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A ruby gem to anonymize your ActiveRecord attributes with ease.


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Anonymize your ActiveRecord models with ease 😎

ActiveRecordAnonymizer uses faker to anonymize your ActiveRecord model's attributes without the need to write custom anonymization logic for each model.

Using ActiveRecordAnonymizer, you can:

  • Anonymize specific attributes of your model (uses faker under the hood)
  • Provide custom anonymization logic for specific attributes
  • Provide custom anonymized columns for each attributes
  • Encrypt anonymized data using ActiveRecord::Encryption (Requires Rails 7+)
  • Environment dependent, so you can decide whether you want to view original data in development and anonymized data in production


Introducing ActiveRecordAnonymizer


Add this line to your application's Gemfile:

gem 'active_record_anonymizer'

And then execute:

$ bundle install

Or install it yourself as:

$ gem install active_record_anonymizer

Install the gem using the following command:

$ bin/rails generate active_record_anonymizer:install

You must have anonymized columns in your Model to store the anonymized data. You can use the following migration generator to add anonymized columns to your existing table:

$ bin/rails generate active_record_anonymizer:anonymize User first_name last_name

This will generate a migration file similar to the following:

class AddAnonymizedColumnsToUser < ActiveRecord::Migration[6.0]
  def change
    add_column :users, :anonymized_first_name, :string
    add_column :users, :anonymized_last_name, :string

Add the following line to your model to enable anonymization:

class User < ApplicationRecord
  # There are other options available, please refer to the Usage section
  anonymize :first_name, :last_name

To populate the anonymized columns, run the following command:

$ bin/rails anonymizer:populate CLASS=User

The CLASS argument is optional, if not provided, it will anonymize all the models with anonymized columns.


Attributes can be anonymized using the anonymize method. The anonymize method takes the following options:

  • :column_name - The name of the column to store the anonymized data. ("anonymized_#{column_name}" by default)
  • :with - The custom logic to anonymize the attribute. (Optional, uses faker by default)
  • :encrypt - Encrypt the anonymized data using ActiveRecord::Encryption (Requires Rails 7+)
class User < ApplicationRecord
  anonymize :first_name, :last_name
  anonymize :email, with: ->(_record) { }
  anonymize :age, with: ->(record) { record.age + 5 }
  anonymize :phone, column_name: :fake_phone_number, with: ->(record) {\d/, 'X') }
  anonymize :address, encrypt: true


You can configure the gem using the following options:

  • :environments - The environments in which the anonymized data should be used. (Defaults to [:development])
  • :skip_update - Skip updating the anonymized data when the record is updated. This ensures your anonymized data remains the same even if it's updated. (Defaults to false)
  • :alias_original_columns - Alias the original columns to the anonymized columns. You can still access the original value of the attribute using the alias original_#{attribute_name}(Defaults to false)
  • :alias_column_name - The name of the alias column. (Defaults to original_#{column_name})
ActiveRecordAnonymizer.configure do |config|
  config.environments = [:development, :staging] # The environments in which the anonymized data should be used
  config.skip_update = true # Skip updating the anonymized data when the record is updated
  config.alias_original_columns = true # Alias the original columns to the anonymized columns
  config.alias_column_name = "original" # The original column will be aliased to "original_#{column_name}


After checking out the repo, run bin/setup to install dependencies. Then, run rake test to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.


Bug reports are welcome on GitHub at

  • Fork the Repository: Start by forking this repo on GitHub.

  • Set Up Your Local Environment: Navigate into the project directory and run the setup script to install dependencies:

    $ cd active_record_anonymizer
    $ bin/setup
  • Create a New Branch: Before making any changes, create a new branch to keep your work organized:
    $ git checkout -b my-new-feature
  • Make Your Changes:

    • Implement your changes or fixes in your local repository.
    • Be sure to keep your changes as focused as possible.
    • If you're working on multiple unrelated improvements, consider making separate branches and pull requests for each.
  • Write Tests: If you're adding a new feature or fixing a bug, please add or update the corresponding tests.

  • Run Tests: Before submitting your changes, run the test suite to ensure everything is working correctly:

    $ bin/rake test
  • Update Documentation: If your changes involve user-facing features or APIs, update the README or other relevant documentation accordingly.

  • Submit a Pull Request: Go to the original ActiveRecordAnonymizer repository on GitHub, and you'll see a prompt to submit a pull request from your new branch.

Bug reports and pull requests are welcome on GitHub at


The gem is available as open source under the terms of the MIT License.


A ruby gem to anonymize your ActiveRecord attributes with ease.