gohugoio/hugo · error

cannot convert type %T to Pages

Error message

cannot convert type %T to Pages

What it means

Thrown by ToPages when the input value matches none of the accepted types (Pages, *Pages, WeightedPages, PageGroup, []Page, or []any of Page). It reports the concrete type so you can see what was passed instead of a page collection.

Solutions

1. Pass a Pages collection (or one of the convertible types: WeightedPages, PageGroup, []Page, []any of Page).
2. Wrap a single Page in page.Pages{p} before passing.
3. For grouped data use ToPagesGroup instead of ToPages.

Example fix

// before
pages, err := page.ToPages(singlePage)
// after
pages, err := page.ToPages(page.Pages{singlePage})

switch seq.(type) {
case page.Pages, *page.Pages, page.WeightedPages, page.PageGroup, []page.Page, []any:
    // convertible
instance:
    return fmt.Errorf("not convertible to Pages: %T", seq)
}

func looksLikePages(seq any) bool {
    switch seq.(type) {
    case page.Pages, *page.Pages, page.WeightedPages, page.PageGroup, []page.Page, []any:
        return true
    }
    return false
}

pages, err := page.ToPages(seq)
if err != nil { /* normalize input or skip */ }

When it happens

Trigger: Calling ToPages (often indirectly via the 'pages' template pipe or collections) with a single Page, a string, a map, a PagesGroup, or any non-page slice whose elements are not Page values.

Common situations: Template authors pass a single Page object or a PageGroups slice where a Pages collection is expected; happens with .Related, .Paginator, or sorting helpers.

Related errors

• %T cannot be merged by language
• invalid argument type %T
• invalid slice type %T
• type %T is not a PageGroup
• argument must be a slice

AI-assisted analysis of gohugoio/hugo@52c9bd7908 (2026-08-09). Data as JSON: /api/errors/23ddfb467b2a5b56. Report an issue: GitHub.

Appendix: source

Thrown at resources/page/pages.go:87

		copy(pages, v)
		return pages, nil
	case []any:
		pages := make(Pages, len(v))
		success := true
		for i, vv := range v {
			p, ok := vv.(Page)
			if !ok {
				success = false
				break
			}
			pages[i] = p
		}
		if success {
			return pages, nil
		}
	}

	return nil, fmt.Errorf("cannot convert type %T to Pages", seq)
}

// Group groups the pages in in by key.
// This implements collections.Grouper.
func (p Pages) Group(key any, in any) (any, error) {
	pages, err := ToPages(in)
	if err != nil {
		return PageGroup{}, err
	}
	return PageGroup{Key: key, Pages: pages}, nil
}

// Len returns the number of pages in the list.
func (p Pages) Len() int {
	return len(p)
}

// ProbablyEq wraps compare.ProbablyEqer

View on GitHub (pinned to 52c9bd7908)