Black Friday 2022 Offers 30% discount in Symfony, Twig and Sylius certifications (offer ends in 8 days)

Lazy Services

Edit this page

Warning: You are browsing the documentation for Symfony 4.2, which is no longer maintained.

Read the updated version of this page for Symfony 6.1 (the current stable version).

Lazy Services

See also

Another way to inject services lazily is via a service subscriber.

Why Lazy Services?

In some cases, you may want to inject a service that is a bit heavy to instantiate, but is not always used inside your object. For example, imagine you have a NewsletterManager and you inject a mailer service into it. Only a few methods on your NewsletterManager actually use the mailer, but even when you don't need it, a mailer service is always instantiated in order to construct your NewsletterManager.

Configuring lazy services is one answer to this. With a lazy service, a "proxy" of the mailer service is actually injected. It looks and acts just like the mailer, except that the mailer isn't actually instantiated until you interact with the proxy in some way.


In order to use the lazy service instantiation, you will need to install the symfony/proxy-manager-bridge package:

$ composer require symfony/proxy-manager-bridge


You can mark the service as lazy by manipulating its definition:

  • YAML
  • XML
  • PHP
# config/services.yaml
        lazy:  true

Once you inject the service into another service, a virtual proxy with the same signature of the class representing the service should be injected. The same happens when calling Container::get() directly.

The actual class will be instantiated as soon as you try to interact with the service (e.g. call one of its methods).

To check if your proxy works you can check the interface of the received object:

// the output should include "ProxyManager\Proxy\LazyLoadingInterface"


If you don't install the ProxyManager bridge and the ocramius/proxy-manager, the container will skip over the lazy flag and directly instantiate the service as it would normally do.

Additional Resources

You can read more about how proxies are instantiated, generated and initialized in the documentation of ProxyManager.

This work, including the code samples, is licensed under a Creative Commons BY-SA 3.0 license.