Fly Sites

Fly Sites are a free service available to customers who signed up before March 28th, 2018. Please email with questions!

What are site enhancements?

Improve your site performance by handling SSL close to visitors, caching frequently used data, and minimizing third party script requirements.

We built this to demonstrate Fly Edge Applications. When you set a site up through our UI, we distribute its configuration data globally. Add backends, rules, and middleware configuration, and your changes are immediately visible across the globe.

Site enhancements use various Edge Application concepts:

Setting up a site

Create a site within Fly by picking a backend (or hosting provider). We'll generate a hostname for you to preview your site. When everythin looks good, point your DNS at your unique hostname.

Our Edge Application will act as your intelligent load balancer, reliable reverse-proxy and flexible API gateway. You can route to your own applications, services, functions, and backends via HTTP Headers and apply Fly Middleware.

With Middleware you can:

As you connect more applications, services, functions, or backends, you can adjust where and how you will route your visitors. For example, you can:

How much do Fly sites cost?

Fly sites are free (as long as they comply with our Terms of Service)!

Quick start

1. Sign up

First things first: create your account.

2. Add a Site

We'll need a Backend to start. This can be a site you host yourself, or somethin you've published on a third party service. You may also add one or more of your own hostnames to each site.

… And more!

3. Update your DNS

The last step is to point your domain to the Fly servers. We have a handy guide below to help you. We'll then be able to issue a valid SSL/TLS certificate for your domain using the Let's Encrypt API.

4. Fly

Congratulations! Your application is now enhanced with a Fly Edge Application. You get Let's Encrypt HTTPS, global load balancing, seamless routing, and proxy level third party integrations.

How to Configure Your DNS with Fly

DNS Verification

The first thing you will need is your own domain.

If you have access to your domain registrar or DNS provider, you're ready to proceed!

Optimal Configuration

Ideally, your DNS provider will support one of:

If not, you can use the alternative configuration.

Once you receive your Fly domain, for example:, you will need to make a record. Where you see, that's where you'd enter your custom domain. :

ALIAS: If your provider offers ALIAS records, it will look similar to this:

Record Name Content
ALIAS or @

ANAME: If your provider offers ANAME records, it will look similar to this:

Record Name Content
ANAME or @

Flattened CNAME: If you use CloudFlare, NameCheap, or 123-Reg, you can setup a flattened CNAME record. If your provider does not offer CNAME flattening, you may need to use the alternative configuration.

Record Name Target
CNAME or @

Alternative Configuration

If your DNS provider does not offer ALIAS or ANAME records or CNAME flattening, you can use an an A record.

To do so, you must first get the IP of your Hostname. You can do that by using ping within your terminal.

super@fly ~ $ ping

Once you have the IP, use it within your A record:

Record Name Target
CNAME or @


Once Fly can reach your domain, you will receive receive the green checkmark.


You are now ready to Fly!


You can plug any application, service, backend, or function into Fly. Whether you're self-hosting your own, using a platform like Heroku or threading together many disparate sources, we've got you covered.

For a complete list of supported backend types, see our backend library.


What are Middleware?

Fly Middleware allow you to implement powerful functions, features, and snippets at the click of a button. Depending on the Middleware, it could add data to the backend request headers, enable analytics, authentication, or security features, change HTML body content, interact with serverless functions, or send custom log or debug information at the end of each request.

What about Beta Middleware?

New Middleware join the party often. The newest will be marked with the Beta tag. These Middleware can be used free of charge until the tag is removed.

Middleware Library

We've got an ever-expanding list of both homemade and third-party Middleware.

You can explore our Middleware Library by clicking here.

Can I write my own?

Almost! If you are interested in writing your own middleware, please email Developers will soon be able to augment their application functionality with custom logic that runs close to users. Middleware can either be specific to a single app, or made available to all customers.


What is the Wormhole?

The Wormhole is a binary that sits beside your application. It can provide:

With Fly + Wormhole, you'll receive Let's Encrypt HTTPS from client-to-Fly and a fast, encrypted tunnel between Fly-and-App; it's true end-to-end encryption.

Learn More
Open Source