> For the complete documentation index, see [llms.txt](https://docs.glesys.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.glesys.com/products/connectivity/load-balancer/how-tos/convert-an-ssl-certificate-from-crt-to-pem-format.md).

# Convert an SSL certificate from CRT to PEM format

Glesys Load Balancer requires SSL certificates to be in PEM format.

***

Glesys Load Balancers accept PEM certificates, and here we explain how to convert your existing CRT‑based certificate to PEM.

When you order a certificate, a CSR file is required. Generating the file also creates a key, for example:

* `domain.com.csr`
* `domain.com.key`

When you purchase a certificate, you also receive the remaining files:

* `domain.com.crt`
* `gs_intermediate_domains_ca.crt` (ca\_bundle)

Three of the files listed above are required to create a complete PEM certificate. Run the following commands to convert your CRT-based certificate to PEM format:

{% code title="Multiple commands" %}

```
openssl x509 -in domain.com.crt -out domain.com.pem
openssl rsa -in domain.com.key >> domain.com.pem
openssl x509 -in gs_intermediate_domains_ca.crt >> domain.com.pem
```

{% endcode %}

Open the `domain.com.pem` file in any text editor, copy its contents, and paste them into the load balancer.