Introduction

Sensible defaults

Hugo offers many configuration options, but its defaults are often sufficient. A new site requires only these settings:

baseURL: https://example.org/
languageCode: en-us
title: My New Hugo Site

baseURL = 'https://example.org/'
languageCode = 'en-us'
title = 'My New Hugo Site'

{
   "baseURL": "https://example.org/",
   "languageCode": "en-us",
   "title": "My New Hugo Site"
}

Only define settings that deviate from the defaults. A smaller configuration file is easier to read, understand, and debug. Keep your configuration concise.

Configuration file

Create a site configuration file in the root of your project directory, naming it hugo.toml, hugo.yaml, or hugo.json, with that order of precedence.

my-project/
└── hugo.toml

A simple example:

baseURL: https://example.org/
languageCode: en-us
params:
  contact:
    email: info@example.org
    phone: +1 202-555-1212
  subtitle: The Best Widgets on Earth
title: ABC Widgets, Inc.

baseURL = 'https://example.org/'
languageCode = 'en-us'
title = 'ABC Widgets, Inc.'
[params]
  subtitle = 'The Best Widgets on Earth'
  [params.contact]
    email = 'info@example.org'
    phone = '+1 202-555-1212'

{
   "baseURL": "https://example.org/",
   "languageCode": "en-us",
   "params": {
      "contact": {
         "email": "info@example.org",
         "phone": "+1 202-555-1212"
      },
      "subtitle": "The Best Widgets on Earth"
   },
   "title": "ABC Widgets, Inc."
}

To use a different configuration file when building your site, use the --config flag:

hugo --config other.toml

Combine two or more configuration files, with left-to-right precedence:

hugo --config a.toml,b.yaml,c.json

Configuration directory

Instead of a single site configuration file, split your configuration by environment, root configuration key, and language. For example:

my-project/
└── config/
    ├── _default/
    │   ├── hugo.toml
    │   ├── menus.en.toml
    │   ├── menus.de.toml
    │   └── params.toml
    └── production/
        └── params.toml

The root configuration keys are build, caches, cascade, deployment, imaging, languages, markup, menus, minify, module, outputs, page, pagination, params, permalinks, privacy, security, segments, server, services, sitemap, and taxonomies.

Omit the root key

When splitting the configuration by root key, omit the root key in the component file. For example, these are equivalent:

params:
  foo: bar

[params]
  foo = 'bar'

{
   "params": {
      "foo": "bar"
   }
}

foo: bar

foo = 'bar'

{
   "foo": "bar"
}

Recursive parsing

Hugo parses the config directory recursively, allowing you to organize the files into subdirectories. For example:

my-project/
└── config/
    └── _default/
        ├── navigation/
        │   ├── menus.de.toml
        │   └── menus.en.toml
        └── hugo.toml

Example

my-project/
└── config/
    ├── _default/
    │   ├── hugo.toml
    │   ├── menus.en.toml
    │   ├── menus.de.toml
    │   └── params.toml
    ├── production/
    │   ├── hugo.toml
    │   └── params.toml
    └── staging/
        ├── hugo.toml
        └── params.toml

Considering the structure above, when running hugo --environment staging, Hugo will use every setting from config/_default and merge staging’s on top of those.

Let’s take an example to understand this better. Let’s say you are using Google Analytics for your website. This requires you to specify a Google tag ID in your site configuration:

services:
  googleAnalytics:
    ID: G-XXXXXXXXX

[services]
  [services.googleAnalytics]
    ID = 'G-XXXXXXXXX'

{
   "services": {
      "googleAnalytics": {
         "ID": "G-XXXXXXXXX"
      }
   }
}

Now consider the following scenario:

1. You don’t want to load the analytics code when running hugo server.
2. You want to use different Google tag IDs for your production and staging environments. For example:
   • G-PPPPPPPPP for production
   • G-SSSSSSSSS for staging

To satisfy these requirements, configure your site as follows:

1. config/_default/hugo.toml

   • Exclude the services.googleAnalytics section. This will prevent loading of the analytics code when you run hugo server.
   • By default, Hugo sets its environment to development when running hugo server. In the absence of a config/development directory, Hugo uses the config/_default directory.

2. config/production/hugo.toml

   • Include this section only:

     services:
       googleAnalytics:
         ID: G-PPPPPPPPP
     

     [services]
       [services.googleAnalytics]
         ID = 'G-PPPPPPPPP'
     

     {
        "services": {
           "googleAnalytics": {
              "ID": "G-PPPPPPPPP"
           }
        }
     }
     

   • You do not need to include other parameters in this file. Include only those parameters that are specific to your production environment. Hugo will merge these parameters with the default configuration.

   • By default, Hugo sets its environment to production when running hugo. The analytics code will use the G-PPPPPPPPP tag ID.

3. config/staging/hugo.toml

   • Include this section only:

     services:
       googleAnalytics:
         ID: G-SSSSSSSSS
     

     [services]
       [services.googleAnalytics]
         ID = 'G-SSSSSSSSS'
     

     {
        "services": {
           "googleAnalytics": {
              "ID": "G-SSSSSSSSS"
           }
        }
     }
     

   • You do not need to include other parameters in this file. Include only those parameters that are specific to your staging environment. Hugo will merge these parameters with the default configuration.

   • To build your staging site, run hugo --environment staging. The analytics code will use the G-SSSSSSSSS tag ID.

Merge configuration settings

Hugo merges configuration settings from themes and modules, prioritizing the project’s own settings. Given this simplified project structure with two themes:

project/
├── themes/
│   ├── theme-a/
│   │   └── hugo.toml
│   └── theme-b/
│       └── hugo.toml
└── hugo.toml

and this project-level configuration:

baseURL: https://example.org/
languageCode: en-us
theme:
- theme-a
- theme-b
title: My New Hugo Site

baseURL = 'https://example.org/'
languageCode = 'en-us'
theme = ['theme-a', 'theme-b']
title = 'My New Hugo Site'

{
   "baseURL": "https://example.org/",
   "languageCode": "en-us",
   "theme": [
      "theme-a",
      "theme-b"
   ],
   "title": "My New Hugo Site"
}

Hugo merges settings in this order:

1. Project configuration (hugo.toml in the project root)
2. theme-a configuration
3. theme-b configuration

The _merge setting within each top-level configuration key controls which settings are merged and how they are merged.

The value for _merge can be one of:

none

No merge.

shallow

Only add values for new keys.

deep

Add values for new keys, merge existing.

Note that you don’t need to be so verbose as in the default setup below; a _merge value higher up will be inherited if not set.

build:
  _merge: none
caches:
  _merge: none
cascade:
  _merge: none
contenttypes:
  _merge: none
deployment:
  _merge: none
frontmatter:
  _merge: none
httpcache:
  _merge: none
imaging:
  _merge: none
languages:
  _merge: none
  en:
    _merge: none
    menus:
      _merge: shallow
    params:
      _merge: deep
markup:
  _merge: none
mediatypes:
  _merge: shallow
menus:
  _merge: shallow
minify:
  _merge: none
module:
  _merge: none
outputformats:
  _merge: shallow
outputs:
  _merge: none
page:
  _merge: none
pagination:
  _merge: none
params:
  _merge: deep
permalinks:
  _merge: none
privacy:
  _merge: none
related:
  _merge: none
security:
  _merge: none
segments:
  _merge: none
server:
  _merge: none
services:
  _merge: none
sitemap:
  _merge: none
taxonomies:
  _merge: none

[build]
  _merge = 'none'
[caches]
  _merge = 'none'
[cascade]
  _merge = 'none'
[contenttypes]
  _merge = 'none'
[deployment]
  _merge = 'none'
[frontmatter]
  _merge = 'none'
[httpcache]
  _merge = 'none'
[imaging]
  _merge = 'none'
[languages]
  _merge = 'none'
  [languages.en]
    _merge = 'none'
    [languages.en.menus]
      _merge = 'shallow'
    [languages.en.params]
      _merge = 'deep'
[markup]
  _merge = 'none'
[mediatypes]
  _merge = 'shallow'
[menus]
  _merge = 'shallow'
[minify]
  _merge = 'none'
[module]
  _merge = 'none'
[outputformats]
  _merge = 'shallow'
[outputs]
  _merge = 'none'
[page]
  _merge = 'none'
[pagination]
  _merge = 'none'
[params]
  _merge = 'deep'
[permalinks]
  _merge = 'none'
[privacy]
  _merge = 'none'
[related]
  _merge = 'none'
[security]
  _merge = 'none'
[segments]
  _merge = 'none'
[server]
  _merge = 'none'
[services]
  _merge = 'none'
[sitemap]
  _merge = 'none'
[taxonomies]
  _merge = 'none'

{
   "build": {
      "_merge": "none"
   },
   "caches": {
      "_merge": "none"
   },
   "cascade": {
      "_merge": "none"
   },
   "contenttypes": {
      "_merge": "none"
   },
   "deployment": {
      "_merge": "none"
   },
   "frontmatter": {
      "_merge": "none"
   },
   "httpcache": {
      "_merge": "none"
   },
   "imaging": {
      "_merge": "none"
   },
   "languages": {
      "_merge": "none",
      "en": {
         "_merge": "none",
         "menus": {
            "_merge": "shallow"
         },
         "params": {
            "_merge": "deep"
         }
      }
   },
   "markup": {
      "_merge": "none"
   },
   "mediatypes": {
      "_merge": "shallow"
   },
   "menus": {
      "_merge": "shallow"
   },
   "minify": {
      "_merge": "none"
   },
   "module": {
      "_merge": "none"
   },
   "outputformats": {
      "_merge": "shallow"
   },
   "outputs": {
      "_merge": "none"
   },
   "page": {
      "_merge": "none"
   },
   "pagination": {
      "_merge": "none"
   },
   "params": {
      "_merge": "deep"
   },
   "permalinks": {
      "_merge": "none"
   },
   "privacy": {
      "_merge": "none"
   },
   "related": {
      "_merge": "none"
   },
   "security": {
      "_merge": "none"
   },
   "segments": {
      "_merge": "none"
   },
   "server": {
      "_merge": "none"
   },
   "services": {
      "_merge": "none"
   },
   "sitemap": {
      "_merge": "none"
   },
   "taxonomies": {
      "_merge": "none"
   }
}

Environment variables

You can also configure settings using operating system environment variables:

export HUGO_BASEURL=https://example.org/
export HUGO_ENABLEGITINFO=true
export HUGO_ENVIRONMENT=staging
hugo

The above sets the baseURL, enableGitInfo, and environment configuration options and then builds your site.

Environment variables simplify configuration for CI/CD deployments like GitHub Pages, GitLab Pages, and Netlify by allowing you to set values directly within their respective configuration and workflow files.

For snake_case variable names, the standard HUGO_ prefix won’t work. Hugo infers the delimiter from the first character following HUGO. This allows for variations like HUGOxPARAMSxAPI_KEY=abcdefgh using any permitted delimiter.

In addition to configuring standard settings, environment variables may be used to override default values for certain internal settings:

DART_SASS_BINARY

(string) The absolute path to the Dart Sass executable. By default, Hugo searches for the executable in each of the paths in the PATH environment variable.

HUGO_FILE_LOG_FORMAT

(string) A format string for the file path, line number, and column number displayed when reporting errors, or when calling the Position method from a shortcode or Markdown render hook. Valid tokens are :file, :line, and :col. Default is :file::line::col.

HUGO_MEMORYLIMIT

New in v0.123.0

(int) The maximum amount of system memory, in gigabytes, that Hugo can use while rendering your site. Default is 25% of total system memory.

HUGO_NUMWORKERMULTIPLIER

(int) The number of workers used in parallel processing. Default is the number of logical CPUs.

Current configuration

Display the complete site configuration with:

hugo config

Display a specific configuration setting with:

hugo config | grep [key]

Display the configured file mounts with:

hugo config mounts