How To Use Turbolinks to Make Fast Rails Apps

by Nate Berkopec (@nateberkopec) of (who?), a Rails performance consultancy.
Summary: Is Rails dead? Can the old Ruby web framework no longer keep up in this age of "native-like" performance? Turbolinks provides one solution. (3030 words/15 minutes)

A perceived benefit of a client-side JS framework is the responsiveness of its interface - updates to the UI are instantaneous. A large amount of application logic (and, usually, state) lives on the client, instead of on the server. The client-side application can perform most tasks without running back to the server for a round-trip. As a result, in the post-V8 era, many developers think traditional server-side languages and frameworks (Ruby, Python, even Java) are simply too slow for modern web applications, which are now supposed to behave like native applications, with instantaneous responses.

Is Rails dead? Can the old Ruby web framework no longer keep up in this age of “native-like” performance?

Shopify (an e-commerce provider that lets you set up your own online shop) has over 150,000 customers and is a Top 1000 site on Alexa.
In addition, Shopify hosts their customers’ sites, with an average of 100ms response times for over 300 million monthly page views. Now that’s Web Scale. And they did it all on Rails.

They’re not the only ones doing huge deployments with blazing fast response times on Rails. DHH claims Basecamp’s average server response time is 27ms. Github averages about 60ms.

But fast response times are only half of the equation. If your server is blazing fast, but you’re spending 500-1000ms on each new page load rendering the page, setting up a new Javascript VM, and re-constructing the entire render tree, your application will be fast, but it won’t be instantaneous.

Enter Turbolinks.

Turbolinks received (and still receives) a huge amount of flak from Rails developers upon its release. Along with pjax, from which it evolved, Turbolinks represented a radical shift in the way Rails apps were intended to be architected. Suddenly, Rails apps had similar characteristics to the “Javascript single-page app” paradigm: no full page loads, pushState usage, and AJAX.

But there was a critical difference between Turbolinks and their SPA brethren: instead of sending data over the wire, Turbolinks sent fully rendered views. Application logic was reclaimed from the client and kept on the server again. Which meant we got to write more Ruby! I’ll call this approach “views-over-the-wire”, becausing we’re sending HTML, not data.

“View-over-the-wire” technologies like turbolinks and pjax have laid mostly out of the limelight since their release in ~2012, despite their usage by such high-profile sites as Shopify and Github. But with Rails 5, Turbolinks is getting a nice upgrade, with new features like partial replacement and a progress bar with a public API. So I wanted to answer for myself the question: how does building an application with Turbolinks feel? Can it be not just fast, but instantaneous?

And just what is an instantaneous response? Thankfully, the guidelines for human-computer interaction speeds have remained constant since they were first discovered in the late 60’s:

  • 0.1 second is about the limit for having the user feel that the system is reacting instantaneously, meaning that no special feedback is necessary except to display the result.
  • 1.0 second is about the limit for the user’s flow of thought to stay uninterrupted, even though the user will notice the delay. Normally, no special feedback is necessary during delays of more than 0.1 but less than 1.0 second, but the user does lose the feeling of operating directly on the data.
  • 10 seconds is about the limit for keeping the user’s attention focused on the dialogue. For longer delays, users will want to perform other tasks while waiting for the computer to finish, so they should be given feedback indicating when the computer expects to be done. Feedback during the delay is especially important if the response time is likely to be highly variable, since users will then not know what to expect. 1(This is the Nielsen Norman group’s interpretation of the linked paper. See the rest of their take on response times here.)1 This is the Nielsen Norman group’s interpretation of the linked paper. See the rest of their take on response times here.

In the non-Turbolinks world, Rails apps usually live in the 1.0 second realm. They return a response in 100-300ms, spend about 200ms loading the HTML and CSSOM, a few hundred more ms rendering and painting, and then likely loads of JS scripting tied to the onload event.

But in the Turbolinks/pjax world, we get to cut out a lot of the work that usually happens when accessing a new page. Consider:

  1. When using Turbolinks, you don’t throw away your entire Javascript runtime on every page. We don’t have to attach a thousand event listeners to the DOM, nor throw out any JS variables between page loads. This requires you to rethink the way you write your Javascript, but the speed benefits are big.
  2. When using Turbolinks partial replacement, we don’t even throw away the entire DOM, instead changing only the parts we need to change.
  3. We don’t have to parse and tokenize the CSS and JS ever again - the CSS Object Model is maintained.

All of this translates into eliminating 200-700ms on each new page. This lets us move out of the 1 second human-computer interaction realm, and start to flirt with the 100 ms realm of “instantaneous” interaction.

As an experiment, I’ve constructed a TodoMVC app using Rails 5 (still under active development) and Turbolinks 3. You can find the application here and the code here. It also utilizes partial replacement, a new feature in Turbolinks 3. Using your browsers favorite development tools, you can confirm that most interactions in the app take about 100-250ms, from the time the click event is registered until the response is painted to the screen.

By comparison, the reference Backbone implementation for TodoMVC takes about 25-40ms. Consider also that our Backbone implementation isn’t making any roundtrips to a server to update data - most TodoMVC implementations use LocalStorage. I can’t find a live TodoMVC implementation that uses a javascript framework and a server backend, so the comparison will have to suffice. In any case, after removing network timing, Turbolinks takes about the same amount of time to update the page state and paint the new elements about as quickly as Backbone. And we didn’t even have to write any new Javascript!

Turbolinks also forces you to do a lot of things you should be doing already with your frontend Javascript - idempotent functions, and not treating your DOM ready hooks like a junk drawer. A lot of people griped about this when Turbolinks came out - but you shouldn’t have been doing it anyway!

Other than asking to re-evaluate the way you write your frontend JS, Turbolinks doesn’t ask you to change a whole lot about the way you write Rails apps. You still get to use all the tools you’re used to on the backend, because what you’re doing is still The Web with a little spice thrown in, not trying to build native applications in Javascript.

load is dead, all hail load!

Look in any Rails project, and for better or for worse, you’re going to see a lot of this:

$(document).ready(function () { ... } );

Rails developers are usually pretty lazy when it comes to Javascript (although, most developers are pretty lazy). JQuery waits for DOMContentLoaded to fire before handing off execution to the function in ready. But Turbolinks takes DOMContentLoaded away from us, and gives us a couple other events instead. Try attaching events to these instead, or using JQuery’s .on to attach event handlers to the document (as opposed to individual nodes). This removal of the load and DOMContentLoaded events can wreak havoc on existing Javascript that uses page ready listeners everywhere, and why I wouldn’t recommend using Turbolinks on existing projects, and using it for greenfield only.

Caching - still a Rails dev’s best friend

DHH has said it a hundred times: Rails is an extraction from Basecamp, and is best used when building Basecamp-like applications. Thus, DHH’s 2013 talk on Basecamp’s architecture is very valuable - most Rails apps should be architected this way, otherwise you’re going to be spending most of your time fighting the framework rather than getting things done.

Most successful large-scale Rails deployments make extensive use of caching. Ruby is a (comparatively) slow language - if you want to keep server response times below 300ms, you simply have to minimize the amount of Ruby you’re running on every request and never calculate the same thing twice.

Caching can be a double-edged sword in small apps, though. Sometimes, the amount of time it takes to read from the cache is more than it takes to just render something. When evaluating whether or not to cache something, always test your apps locally in production mode, with production-size datasets (hopefully just a copy of the production DB, if your company allows it). The only way to know for sure if caching is the right solution for a block of code is to measure, measure, measure. And how do we do that?

rack-mini-profiler and the flamegraph

has become an indispensable part of my Ruby workflow. It’s written by the incredible Sam Saffron, who’s doing absolutely vital work (along with others) on Ruby speed over at

rack-mini-profiler puts a little white box at the upper left of a page, showing you exactly how long the last request took to process, along with a breakdown of how many SQL queries were executed. The amount of unnecessary SQL queries I’ve eliminated with this tool must number in the thousands.

But that’s not even rack-mini-profiler’s killer feature. If you add in the flamegraph gem to your Gemfile, you get a killer flame graph showing exactly how long rendering each part of your page took. This is invaluable when tracking down exactly what parts of the page took the most time to render.

Chrome Timeline - the sub-100ms developer’s best friend

When you’re aiming for a sub-100ms-to-glass Turbolinks app, every ms counts. So allow me introduce you to my little friend: the Chrome Timeline.

This bad boy shows you, in flamegraph format, exactly where each of your 100ms goes. Read up on Google’s documentation on exactly how to use this tool, and exactly what means what, but it’ll give you a great idea of which parts of your Javascript are slowing down your page.

Non-RESTful redirects

100ms-to-glass is not a lot of time. In most cases, you may not even have time to redirect. Consider this typical bit of Rails controller logic:

def create
  thing =[:thing])
    redirect_to #...

Unfortunately, you’ve just doubled the number of round-trips to the server - one for the POST, and one for the GET when you get your response back from the redirect. I’ve found that this alone puts you beyond 100ms. With remote forms and Turbolinks, it seems to be far better to do non-RESTFUL responses here and just re-render the (updated) index view.

Be wary of partials

Partials in Rails have always been slow-ish. They’re fast enough if you’re aiming for 300ms responses, but in the 100ms-to-glass world, we can’t really afford any less than a 50ms server response time. Be wary of using partials, cache them if you can, and always benchmark when adding a new partial.

Response time goals and Apache Bench

Another key tool for keeping your Turbolinks-enabled Rails app below 100ms-to-glass is to keep your server response times ridiculously fast - 50ms should be your goal. Apache Bench
is a great tool for doing this, but siege is another popular tool that does the same thing - slams your web server as fast as it can to get an idea of your max requests/second.

Be sure to load up your rails server in production mode when benchmarking with these tools so that you don’t have code reloading slowing down each request!

In addition, be sure to test with production (or extremely production-like) data. If queries return 100 rows in development but return 1000 rows in production, you’re going to see very different performance. We want our development environment to be as similar to production as possible.

Common mistakes

  • Be absolutely certain that a page load that you think is Turbolinks enabled, is actually Turbolinks enabled. Click a link with the Developer console open - if the console says something like “Navigated to”, that link wasn’t Turbolinks-enabled.
  • Don’t render responses that do things like append items to the current page. Instead, a Turbolinks-enabled action should return a full HTML page. Let Turbolinks do the work of swapping out the document, instead of writing your own, manual “$(“#todo-list”).append(“<%= j(render(@todo)) %>”);” calls. For an example, check out my TodoMVC implementation, which only uses an index template. Keep state (elements having certain classes, for example) in the template, rather than allowing too much DOM state to leak into your Javascript. It’s just unnecessary work that Turbolinks frees us from doing.

Limitations and caveats

Turbolinks may not fare well in more complex UI interactions - the TodoMVC example is very simple. Caching will be required when scaling, which some people think is too complex. I think that with smart key-based expiration, and completely avoiding manual cache expiration or “sweepers”, it isn’t too bad.

Turbolinks doesn’t play great with client side JS frameworks, due to the transition cache and the lack of the load event. Be wary of multiple instances of your app being generated, and be careful of Turbolinks’ transition cache.

Integration testing is still a pain. Capybara and selenium-webdriver, though widely used, remain difficult to configure properly and, seemingly no matter what, are not deterministic and occasionally experience random failures.

Conclusion: “View-over-the-wire” is better than it got credit for

Overall, I quite enjoyed the Turbolinks development experience, and mostly, as a user, I’m extremely impressed with the user experience it produces. Getting serious about Rails performance and using a “view-over-the-wire” technology means that Rails apps will deliver top-shelf experiences on par with any clientside framework.



Want a faster website?

I'm Nate Berkopec (@nateberkopec). I write online about web performance from a full-stack developer's perspective. I primarily write about frontend performance and Ruby backends. If you liked this article and want to hear about the next one, click below. I don't spam - you'll receive about 1 email per week. It's all low-key, straight from me.

Products from Speedshop

The Complete Guide to Rails Performance is a full-stack performance book that gives you the tools to make Ruby on Rails applications faster, more scalable, and simpler to maintain.

Learn more

The Rails Performance Workshop is the big brother to my book. Learn step-by-step how to make your Rails app as fast as possible through a comprehensive video and hands-on workshop. Available for individuals, groups and large teams.

Learn more

More Posts

Announcing the Rails Performance Apocrypha

I've written a new book, compiled from 4 years of my email newsletter.

Read more

We Made Puma Faster With Sleep Sort

Puma 5 is a huge major release for the project. It brings several new experimental performance features, along with tons of bugfixes and features. Let's talk about some of the most important ones.

Read more

The Practical Effects of the GVL on Scaling in Ruby

MRI Ruby's Global VM Lock: frequently mislabeled, misunderstood and maligned. Does the GVL mean that Ruby has no concurrency story or CaN'T sCaLe? To understand completely, we have to dig through Ruby's Virtual Machine, queueing theory and Amdahl's Law. Sounds simple, right?

Read more

The World Follows Power Laws: Why Premature Optimization is Bad

Programmers vaguely realize that 'premature optimization is bad'. But what is premature optimization? I'll argue that any optimization that does not come from observed measurement, usually in production, is premature, and that this fact stems from natural facts about our world. By applying an empirical mindset to performance, we can...

Read more

Why Your Rails App is Slow: Lessons Learned from 3000+ Hours of Teaching

I've taught over 200 people at live workshops, worked with dozens of clients, and thousands of readers to make their Rails apps faster. What have I learned about performance work and Rails in the process? What makes apps slow? How do we make them faster?

Read more

3 ActiveRecord Mistakes That Slow Down Rails Apps: Count, Where and Present

Many Rails developers don't understand what causes ActiveRecord to actually execute a SQL query. Let's look at three common cases: misuse of the count method, using where to select subsets, and the present? predicate. You may be causing extra queries and N+1s through the abuse of these three methods.

Read more

The Complete Guide to Rails Performance, Version 2

I've completed the 'second edition' of my course, the CGRP. What's changed since I released the course two years ago? Where do I see Rails going in the future?

Read more

A New Ruby Application Server: NGINX Unit

NGINX Inc. has just released Ruby support for their new multi-language application server, NGINX Unit. What does this mean for Ruby web applications? Should you be paying attention to NGINX Unit?

Read more

Malloc Can Double Multi-threaded Ruby Program Memory Usage

Memory fragmentation is difficult to measure and diagnose, but it can also sometimes be very easy to fix. Let's look at one source of memory fragmentation in multi-threaded CRuby programs: malloc's per-thread memory arenas.

Read more

Configuring Puma, Unicorn and Passenger for Maximum Efficiency

Application server configuration can make a major impact on the throughput and performance-per-dollar of your Ruby web application. Let's talk about the most important settings.

Read more

Is Ruby Too Slow For Web-Scale?

Choosing a new web framework or programming language for the web and wondering which to pick? Should performance enter your decision, or not?

Read more

Railsconf 2017: The Performance Update

Did you miss Railsconf 2017? Or maybe you went, but wonder if you missed something on the performance front? Let me fill you in!

Read more

Understanding Ruby GC through GC.stat

Have you ever wondered how the heck Ruby's GC works? Let's see what we can learn by reading some of the statistics it provides us in the GC.stat hash.

Read more

Rubyconf 2016: The Performance Update

What happened at RubyConf 2016 this year? A heck of a lot of stuff related to Ruby performance, that's what.

Read more

What HTTP/2 Means for Ruby Developers

Full HTTP/2 support for Ruby web frameworks is a long way off - but that doesn't mean you can't benefit from HTTP/2 today!

Read more

How Changing WebFonts Made 10x Faster

WebFonts are awesome and here to stay. However, if used improperly, they can also impose a huge performance penalty. In this post, I explain how painted 10x faster just by making a few changes to its WebFonts.

Read more

Page Weight Doesn't Matter

The total size of a webpage, measured in bytes, has little to do with its load time. Instead, increase network utilization: make your site preloader-friendly, minimize parser blocking, and start downloading resources ASAP with Resource Hints.

Read more

Hacking Your Webpage's Head Tags for Speed and Profit

One of the most important parts of any webpage's performance is the content and organization of the head element. We'll take a deep dive on some easy optimizations that can be applied to any site.

Read more

How to Measure Ruby App Performance with New Relic

New Relic is a great tool for getting the overview of the performance bottlenecks of a Ruby application. But it's pretty extensive - where do you start? What's the most important part to pay attention to?

Read more

Ludicrously Fast Page Loads - A Guide for Full-Stack Devs

Your website is slow, but the backend is fast. How do you diagnose performance issues on the frontend of your site? We'll discuss everything involved in constructing a webpage and how to profile it at sub-millisecond resolution with Chrome Timeline, Google's flamegraph-for-the-browser.

Read more

Action Cable - Friend or Foe?

Action Cable will be one of the main features of Rails 5, to be released sometime this winter. But what can Action Cable do for Rails developers? Are WebSockets really as useful as everyone says?

Read more

rack-mini-profiler - the Secret Weapon of Ruby and Rails Speed

rack-mini-profiler is a powerful Swiss army knife for Rack app performance. Measure SQL queries, memory allocation and CPU time.

Read more

Scaling Ruby Apps to 1000 Requests per Minute - A Beginner's Guide

Most "scaling" resources for Ruby apps are written by companies with hundreds of requests per second. What about scaling for the rest of us?

Read more

Make your Ruby or Rails App Faster on Heroku

Ruby apps in the memory-restrictive and randomly-routed Heroku environment don't have to be slow. Achieve <100ms server response times with the tips laid out below.

Read more

The Complete Guide to Rails Caching

Caching in a Rails app is a little bit like that one friend you sometimes have around for dinner, but should really have around more often.

Read more


Get notified on new posts.

Straight from the author. No spam, no bullshit. Frequent email-only content.