| Current defaults | Minimum supported |
| --- | --- |
| **Elixir `1.18.4`**<br>**Erlang/OTP `28.0.2`**<br>Services created before **2025-06-12** have different default versions. [See below](/content/docs/elixir-erlang-versions#history-of-default-elixir-versions/index.html). | **Elixir `1.12.0`**<br>**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](/content/docs/configure-environment-variables/index.html) 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](https://hexdocs.pm/elixir/compatibility-and-deprecations.html#between-elixir-and-erlang-otp).

## 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](/content/docs/elixir-erlang-versions/index.html)  
- [History of default Elixir versions](/content/docs/elixir-erlang-versions#history-of-default-elixir-versions/index.html)

# Ready to help.