> For the complete documentation index, see [llms.txt](https://gitbook-open-v2-preview.gitbook.workers.dev/url/gitbook.com/docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://gitbook-open-v2-preview.gitbook.workers.dev/url/gitbook.com/docs/help-center/published-documentation/custom-domains.md).

# Custom domains

- [My custom subdomain isn't working](https://gitbook-open-v2-preview.gitbook.workers.dev/url/gitbook.com/docs/help-center/published-documentation/custom-domains/my-custom-subdomain-isnt-working.md): A quick guide on how to troubleshoot dns issues in GitBook
- [Change or update my custom domain in GitBook](https://gitbook-open-v2-preview.gitbook.workers.dev/url/gitbook.com/docs/help-center/published-documentation/custom-domains/change-or-update-my-custom-domain-in-gitbook.md): This is a quick guide on how to change or update your custom domain in GitBook
- [How can I solve the "path is already taken" error?](https://gitbook-open-v2-preview.gitbook.workers.dev/url/gitbook.com/docs/help-center/published-documentation/custom-domains/how-can-i-solve-the-path-is-already-taken-error.md)
- [How can I change the slug in the URL?](https://gitbook-open-v2-preview.gitbook.workers.dev/url/gitbook.com/docs/help-center/published-documentation/custom-domains/how-can-i-change-the-slug-in-the-url.md)


---

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