reflect.IsImageResource

Reports whether the given value is a Resource object representing a processable image.

Syntax

reflect.IsImageResource INPUT

Returns

bool

A processable image is an image file characterized by one of the following media types:

image/gif
image/jpeg
image/png
image/tiff
image/webp

Hugo can decode and encode these image formats, allowing you to use any of the resource methods applicable to images such as Width, Height, Crop, Fill, Fit, Resize, etc.

With this project structure:

project/
├── assets/
│   ├── a.json
│   ├── b.avif
│   └── c.jpg
└── content/
    └── example/
        ├── index.md
        ├── d.json
        ├── e.avif
        └── f.jpg

These are the values returned by the reflect.IsImageResource function:

layouts/page.html

{{ with resources.Get "a.json" }}
  {{ reflect.IsImageResource . }} → false
{{ end }}

{{ with resources.Get "b.avif" }}
  {{ reflect.IsImageResource . }} → false
{{ end }}

{{ with resources.Get "c.jpg" }}
  {{ reflect.IsImageResource . }} → true
{{ end }}

In the example above, the b.avif image is not a processable image because Hugo can neither decode nor encode the AVIF image format.

layouts/page.html

{{ with .Resources.Get "d.json" }}
  {{ reflect.IsImageResource . }} → false
{{ end }}

{{ with .Resources.Get "e.avif" }}
  {{ reflect.IsImageResource . }} → false
{{ end }}

{{ with .Resources.Get "f.jpg" }}
  {{ reflect.IsImageResource . }} → true
{{ end }}

In the example above, the e.avif image is not a processable image because Hugo can neither decode nor encode the AVIF image format.

layouts/page.html

{{ with site.GetPage "/example" }}
  {{ reflect.IsImageResource . }} → false
{{ end }}

Last updated: January 5, 2026 : content: Fix typo (0d841a59e)

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