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A quick and easy way to add random, customizable, public-facing IDs to your models.
 Project Readme


Identifiable makes is really quick and easy way to add random, customizable, public-facing IDs to your models. These are great for URLs and reports, where you might not want to share the record's id attribute.

Why do I need public-facing IDs?

If you're asking this question, you probably use your record's id attribute as its identifier in its URL. This can be an issue for two main reasons:

  1. If you've got a low number of records (if you're just getting started, for instance) it might look unprofessional to have a low ID number. Simply put, https://example.app/orders/14 doesn't look as good as https://example.app/orders/87133275. Even if you've only got 14 orders so far, you might want to look like you've got more. Fake it 'til you make it!
  2. If you're exposing things to the open web, using auto-incrementing IDs means someone hoping to scrape your app can just increment the ID parameter in the URL and get everything. With randomly generated public IDs, scrapers can't just add 1 to each ID to find valid pages.

Identifiable makes it really simple to generate and use random public-facing IDs in your Rails applications.

# Before:
orders_url(id: @order.id) # → https://example.app/orders/14

# After:
orders_url(id: @order.public_id) # → https://example.app/orders/87133275


Add this line to your application's Gemfile:

gem 'identifiable'

Then run bundle install and you'll be set.


Adding Identifiable to your Rails models couldn't be simpler. The easiest, most default way to add public IDs is to just add identifiable to your model. This'll default to 8-character long numeric public IDs (like 23843274 or 98237268, for instance) on the public_id column of your model. These public IDs will be automatically set when you create your records.

class Order < ApplicationRecord

Identifiable doesn't create the columns for your model, so you will need to add those yourself when you create your models (or add the columns when adding Identifiable to an existing model). These columns will also need an index on them. To add a public_id string column with an index to your Order model, you can run in your command line:

bundle exec rails generate migration add_public_id_to_orders public_id:index
bundle exec rails db:migrate

If you don't have the public id column set up, Identifiable will raise an error.

Finding by your model's public ID

If you're used to using Model.find(id) in your controllers, no need to fret! Now you can replace it with Model.find_by_public_id!(public_id) and you'll get the same behavior, including raising ActiveRecord::RecordNotFound if the record doesn't exist. It's plug-and-play.

You can also use Model.find_by_public_id(public_id), which is similar, but does not raise an error if the record doesn't exist, you'll just get nil instead.

Because your public ID is just a column in your database, you can also use all the standard Rails ways of accessing records, including #where and #find_by.

Adding public IDs to existing records

Public IDs are assigned when saving a record if the public ID isn't already set, so to add public IDs to existing records, you just need to re-run a #save on each one, like so:

Order.all.find_each do |order|


While Identifiable strives to have useful defaults, you may want to customize your public IDs for your particular application, or even for particular models in your application.

Different public ID styles

By default, Identifiable will generate numeric public IDs, with each character between 0 and 9, but it can also generate alphanumeric public IDs and UUID public IDs. To choose your public ID style, simply pass it in as a parameter to identifiable on your model.

class Order < ApplicationRecord
  # Valid options for style are :numeric (default), :alphanumeric, and :uuid
  identifiable style: :alphanumeric

Here's how each available style looks:

  • :numeric produces public ids with numbers between 0 and 9 for each character, and looks like 23843274.
  • :alphanumeric produces public ids with uppercase letters (A-Z), lowercase letters (a-z), and numbers (0-9) for each character, and looks like a3ZG8fkP.
  • :uuid produces public ids that match the UUID specification in RFC 4122, and look like adea0700-94de-4075-bbf0-7853cffcca50.

Changing the public ID column

By default, Identifiable will assume your public ID column is public_id, but you can pick another column if you want. For instance, you might want to use share_link_id for a publicly shareable link. To do so, simply pass the column name as a symbol to identifiable on your model.

class Order < ApplicationRecord
  # Defaults to `:public_id`. In this example, the column `share_link_id` must
  # exist in the `orders` table, otherwise Identifiable will raise an error.
  identifiable column: :share_link_id

Changing the length of the public ID

Numeric and alphanumeric public IDs default to 8 characters long, but in your application you might want more (or less) than that. The length parameter of identifiable is used to set the length of these public IDs, and defaults to 8.

class Order < ApplicationRecord
  # This configuration will produce 16 character long alphanumeric public IDs.
  identifiable style: :alphanumeric, length: 16

The length parameter is ignored if you're using style: :uuid, because UUIDs already have a fixed length. The length parameter also needs be an Integer, and can't be less than 4 or greater than 128. If any of these constraints are broken, Identifiable will raise an error letting you know.


I built Identifiable because I never could quite get the other gems that do similar things quite the way that I liked them. You might have the same experience with Identifiable, so if you try Identifiable and find that it's not quite to your tastes, try out some of these alternatives:

  • Hashid Rails uses hashids to seamlessly create hex strings for your primary keys. It's nice because it doesn't require an extra column in your database, but it's limited in what it can do.
  • Public UID is a real power-users public ID gem, and until I made this it was the main way I would build public ID features into the apps I was working on, but I found it too heavy for what I wanted 90% of the time, which is why Identifiable is customizable, but not too customizable. If you find Identifiable isn't customizable or powerful enough for your needs, give Public UID a go!


Bug reports and pull requests are welcome on GitHub. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the code of conduct while interacting in the project's codebases, issue trackers, chat rooms, and mailing lists.


The gem is available as open source under the terms of the MIT License. If you or your organization need a custom, commercial license for any reason, send me an email and I'll be happy to set something up for you.