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This repo is no longer maintained. Check out the latest at for the original rack-mini-profiler gem instead.


This is a fork the Ruby folder of which includes some quick fixes to make the original rack-mini-profiler gem a little more usable. I will keep in in sync with Ruby related development from the original repo and consolidate any useful changes here into pull requests for the original repo

  • Add gem 'miniprofiler', require: 'rack-mini-profiler' to your Gemfile (instead of gem 'rack-mini-profiler')
  • miniprofiler's version uses x.y.z.t syntax in order to more easily sync with rack-mini-profiler's x.y.z SemVer versioning. I will increase t whenever I make a patch
  • Note to use MiniProfiler outside development and production env in Rails, set Rack::MiniProfiler.config.pre_authorize_cb = lambda {|env| true } in an initializer file in Rails. I recommend wrapping all Rack::MiniProfiler calls under your env check. E.g. if %w(development staging).include?(Rails.env)
  • More to come

Original README below:


Middleware that displays speed badge for every html page. Designed to work both in production and in development.

Using rack-mini-profiler in your app

Install/add to Gemfile

gem 'rack-mini-profiler'

Using Rails:

All you have to do is include the Gem and you're good to go in development.

rack-mini-profiler is designed with production profiling in mind. To enable that just run Rack::MiniProfiler.authorize_request once you know a request is allowed to profile.

For example:

# A hook in your ApplicationController
def authorize
  if current_user.is_admin?

Using Builder:

require 'rack-mini-profiler'
builder = do
  use Rack::MiniProfiler

  map('/')    { run get }

Using Sinatra:

require 'rack-mini-profiler'
class MyApp < Sinatra::Base
  use Rack::MiniProfiler


By default, rack-mini-profiler stores its results in a memory store:

# our default = Rack::MiniProfiler::MemoryStore

There are 2 other available storage engines, RedisStore and FileStore.

MemoryStore is stores results in a processes heap - something that does not work well in a multi process environment. FileStore stores results in the file system - something that may not work well in a multi machine environment.

Additionally you may implement an AbstractStore for your own provider.

Rails hooks up a FileStore for all environments.

Running the Specs

$ rake build
$ rake spec

Additionally you can also run autotest if you like.

Configuration Options

You can set configuration options using the configuration accessor on Rack::MiniProfiler:

# Have Mini Profiler show up on the right
Rack::MiniProfiler.config.position = 'right'

In a Rails app, this can be done conveniently in an initializer such as config/initializers/mini_profiler.rb.

Available Options

  • pre_authorize_cb - A lambda callback you can set to determine whether or not mini_profiler should be visible on a given request. Default in a Rails environment is only on in development mode. If in a Rack app, the default is always on.
  • position - Can either be 'right' or 'left'. Default is 'left'.
  • skip_schema_queries - Whether or not you want to log the queries about the schema of your tables. Default is 'false', 'true' in rails development.

Special query strings

If you include the query string pp=help at the end of your request you will see the various option you have. You can use these options to extend or contract the amount of diagnostics rack-mini-profiler gathers.