Setting Your Elixir and Erlang Versions – Render Docs

Current defaults Minimum supported
Elixir 1.18.4
Erlang/OTP 28.0.2
Services created before 2025-06-12 have different default versions. See below.
Elixir 1.12.0
Erlang/OTP 24.3.4

Elixir version 1.18.4 and Erlang/OTP version 28.0.2 are the defaults for Render services created on or after 2025-06-12.

You can specify different Elixir and Erlang/OTP versions by setting the following environment variables for your service:

Variable Example Value
ELIXIR_VERSION 1.19.5
ERLANG_VERSION 28.3

Your Elixir version must be compatible with your Erlang/OTP version!

Otherwise, your service's builds will fail. For compatibility information, see the Elixir documentation.

History of default Elixir versions

If you don't set an Elixir version for your service, Render's default version depends on when you originally created the service:

Service Creation Date Default Elixir Version
2025-06-12 and later 1.18.4
2024-03-05 to 2025-06-12 1.16.1
2023-11-01 to 2024-03-05 1.15.6
Before 2023-11-01 1.9.4
Setting Your Elixir and Erlang Versions

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