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Merged
cderv merged 5 commits into from
Feb 2, 2026
+168 −44
Merged

fix(listings): lazy loading for listing auto-detected images #13953

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d71315f
fix: `listing:image-lazy-loading` does not work for values of `true` …
mcanouil Jan 25, 2026
7b47ce8
Merge branch 'main' into fix/issue13951
mcanouil Feb 1, 2026
64c5e52
test: update tests for lazy loading in more scenarios
mcanouil Feb 1, 2026
8c5cb91
chore: update changelog entry
mcanouil Feb 1, 2026
82cfc48
test: tweak lazy-loading listing test
mcanouil Feb 1, 2026
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1 change: 1 addition & 0 deletions news/changelog-1.9.md
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Original file line number Diff line number Diff line change
Expand Up @@ -94,6 +94,7 @@ All changes included in 1.9:
- ([#13716](https://github.com/quarto-dev/quarto-cli/issues/13716)): Fix draft pages showing blank during preview when pre-render scripts are configured.
- ([#13847](https://github.com/quarto-dev/quarto-cli/pull/13847)): Open graph title with markdown is now processed correctly. (author: @mcanouil)
- ([#13910](https://github.com/quarto-dev/quarto-cli/issues/13910)): Add support for `logo: false` to disable sidebar and navbar logos when using `_brand.yml`. Works in website projects (`sidebar.logo: false`, `navbar.logo: false`) and book projects (`book.sidebar.logo: false`, `book.navbar.logo: false`).
- ([#13951](https://github.com/quarto-dev/quarto-cli/issues/13951)): Fix `image-lazy-loading` not applying `loading="lazy"` attribute to auto-detected listing images.

### `book`

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26 changes: 19 additions & 7 deletions src/project/types/website/listing/website-listing-read.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -393,14 +393,16 @@ export function completeListingItems(
debug(`[listing] Processing image match`);
const progressive = imgMatch[1] === "true";
const imgHeight = imgMatch[2];
const listingId = imgMatch[3];
const docRelativePath = imgMatch[4];
const lazy = imgMatch[3] !== "false";
const listingId = imgMatch[4];
const docRelativePath = imgMatch[5];
const docAbsPath = join(projectOutputDir(context), docRelativePath);
const imgPlaceholder = imagePlaceholder(
listingId,
docRelativePath,
progressive,
imgHeight,
lazy,
);
debug(`[listing] ${docAbsPath}`);
debug(`[listing] ${imgPlaceholder}`);
Expand Down Expand Up @@ -435,6 +437,7 @@ export function completeListingItems(
},
progressive,
imgHeight,
lazy,
);

debug(`[listing] replacing: ${docAbsPath}`);
Expand All @@ -454,7 +457,7 @@ export function completeListingItems(
};
fileContents = fileContents.replace(
imgPlaceholder,
imageSrc(imagePreview, progressive, imgHeight),
imageSrc(imagePreview, progressive, imgHeight, lazy),
);
} else {
debug(`[listing] using empty div: ${docAbsPath}`);
Expand Down Expand Up @@ -501,11 +504,14 @@ export function imagePlaceholder(
file: string,
progressive: boolean,
height?: string,
lazy?: boolean,
): string {
return file
? `<!-- img(9CEB782EFEE6)[progressive=${
progressive ? "true" : "false"
}, height=${height ? height : ""}]:${id}:${file} -->`
}, height=${height ? height : ""}, lazy=${
lazy === false ? "false" : "true"
}]:${id}:${file} -->`
: "";
}

Expand All @@ -517,7 +523,7 @@ const descriptionPlaceholderRegex =
/<!-- desc\(5A0113B34292\)\[max\=(.*)\]:(.*) -->/;

const imagePlaceholderRegex =
/<!-- img\(9CEB782EFEE6\)\[progressive\=(.*), height\=(.*)\]:(.*):(.*) -->/;
/<!-- img\(9CEB782EFEE6\)\[progressive\=(.*), height\=(.*), lazy\=(.*)\]:(.*):(.*) -->/;

function hydrateListing(
format: Format,
Expand Down Expand Up @@ -1202,8 +1208,14 @@ async function listItemFromFile(
}
}

function imageSrc(image: PreviewImage, progressive: boolean, height?: string) {
return `<p class="card-img-top"><img ${
function imageSrc(
image: PreviewImage,
progressive: boolean,
height?: string,
lazy?: boolean,
) {
const lazyAttr = lazy === false ? "" : "loading='lazy' ";
return `<p class="card-img-top"><img ${lazyAttr}${
progressive ? "data-src" : "src"
}="${image.src}" ${image.alt ? `alt="${image.alt}" ` : ""}${
height ? `style="height: ${height};" ` : ""
Expand Down
2 changes: 2 additions & 0 deletions src/project/types/website/listing/website-listing-template.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -447,13 +447,15 @@ export function reshapeListing(
listingId: string,
itemNumber: number,
itemPath: string,
lazy?: boolean,
) => {
const pageSize = listing[kPageSize];
return imagePlaceholder(
listingId,
itemPath,
itemNumber > pageSize,
listing[kImageHeight] as string,
lazy,
);
};

Expand Down
2 changes: 1 addition & 1 deletion src/resources/projects/website/listing/item-default.ejs.md
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Original file line number Diff line number Diff line change
Expand Up @@ -45,7 +45,7 @@ print(`<div class="metadata-value listing-${field}">${listing.utilities.outputLi
<% if (item.image) { %>
<%= listing.utilities.img(itemNumber, item.image, "thumbnail-image", item['image-alt'], item['image-lazy-loading'] ?? listing['image-lazy-loading']) %>
<% } else { %>
<%= listing.utilities.imgPlaceholder(listing.id, itemNumber, item.outputHref) %>
<%= listing.utilities.imgPlaceholder(listing.id, itemNumber, item.outputHref, item['image-lazy-loading'] ?? listing['image-lazy-loading']) %>
<% } %>
</a></div>
```
Expand Down
2 changes: 1 addition & 1 deletion src/resources/projects/website/listing/item-grid.ejs.md
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Expand Up @@ -57,7 +57,7 @@ return !["title", "image", "image-alt", "date", "author", "subtitle", "descripti
<% } else { %>

```{=html}
<%= listing.utilities.imgPlaceholder(listing.id, itemNumber, item.outputHref) %>
<%= listing.utilities.imgPlaceholder(listing.id, itemNumber, item.outputHref, item['image-lazy-loading'] ?? listing['image-lazy-loading']) %>
```

<% } %>
Expand Down
2 changes: 1 addition & 1 deletion src/resources/projects/website/listing/listing-table.ejs.md
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Expand Up @@ -57,7 +57,7 @@ if (field === "image") {
if (item.image) {
value = listing.utilities.img(itemNumber, item[field], "", item['image-alt'], item['image-lazy-loading'] ?? listing['image-lazy-loading']);
} else {
value = listing.utilities.imgPlaceholder(listing.id, itemNumber, item.outputHref);
value = listing.utilities.imgPlaceholder(listing.id, itemNumber, item.outputHref, item['image-lazy-loading'] ?? listing['image-lazy-loading']);
}
}
return listing.utilities.outputLink(item, field, value, `listing-${field}`);
Expand Down
25 changes: 16 additions & 9 deletions tests/docs/smoke-all/listings/image-lazy-loading/blog/index-default-eager.qmd
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Expand Up @@ -7,15 +7,22 @@ listing:
- image
image-lazy-loading: false
_quarto:
html:
ensureHtmlElements:
-
- "img[src='https://placeholder.co/100/100.png']"
- "img[src='https://placeholder.co/200/200.png']"
- "img[loading='lazy'][src='https://placeholder.co/300/300.png']"
-
- "img[loading='lazy'][src='https://placeholder.co/100/100.png']"
- "img[loading='lazy'][src='https://placeholder.co/200/200.png']"
render-project: true
tests:
html:
ensureHtmlElements:
-
- "img[src='https://placeholder.co/100/100.png']"
- "img[src='https://placeholder.co/200/200.png']"
- "img[loading='lazy'][src='https://placeholder.co/300/300.png']"
- "img[src='https://placeholder.co/400/400.png']"
- "img[src='https://placeholder.co/500/500.png']"
- "img[loading='lazy'][src='https://placeholder.co/600/600.png']"
-
- "img[loading='lazy'][src='https://placeholder.co/100/100.png']"
- "img[loading='lazy'][src='https://placeholder.co/200/200.png']"
- "img[loading='lazy'][src='https://placeholder.co/400/400.png']"
- "img[loading='lazy'][src='https://placeholder.co/500/500.png']"
---

## Hello, here's some listings with `image-lazy-loading: false`
7 changes: 6 additions & 1 deletion tests/docs/smoke-all/listings/image-lazy-loading/blog/index-default.qmd
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Original file line number Diff line number Diff line change
Expand Up @@ -6,15 +6,20 @@ listing:
- title
- image
_quarto:
render-project: true
tests:
html:
ensureHtmlElements:
-
-
- "img[loading='lazy'][src='https://placeholder.co/100/100.png']"
- "img[src='https://placeholder.co/200/200.png']"
- "img[loading='lazy'][src='https://placeholder.co/300/300.png']"
- "img[loading='lazy'][src='https://placeholder.co/400/400.png']"
- "img[src='https://placeholder.co/500/500.png']"
- "img[loading='lazy'][src='https://placeholder.co/600/600.png']"
-
- "img[loading='lazy'][src='https://placeholder.co/200/200.png']"
- "img[loading='lazy'][src='https://placeholder.co/500/500.png']"
---

## Hello, here's some listings
25 changes: 16 additions & 9 deletions tests/docs/smoke-all/listings/image-lazy-loading/blog/index-grid-eager.qmd
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Original file line number Diff line number Diff line change
Expand Up @@ -7,15 +7,22 @@ listing:
- image
image-lazy-loading: false
_quarto:
html:
ensureHtmlElements:
-
- "img[src='https://placeholder.co/100/100.png']"
- "img[src='https://placeholder.co/200/200.png']"
- "img[loading='lazy'][src='https://placeholder.co/300/300.png']"
-
- "img[loading='lazy'][src='https://placeholder.co/100/100.png']"
- "img[loading='lazy'][src='https://placeholder.co/200/200.png']"
render-project: true
tests:
html:
ensureHtmlElements:
-
- "img[src='https://placeholder.co/100/100.png']"
- "img[src='https://placeholder.co/200/200.png']"
- "img[loading='lazy'][src='https://placeholder.co/300/300.png']"
- "img[src='https://placeholder.co/400/400.png']"
- "img[src='https://placeholder.co/500/500.png']"
- "img[loading='lazy'][src='https://placeholder.co/600/600.png']"
-
- "img[loading='lazy'][src='https://placeholder.co/100/100.png']"
- "img[loading='lazy'][src='https://placeholder.co/200/200.png']"
- "img[loading='lazy'][src='https://placeholder.co/400/400.png']"
- "img[loading='lazy'][src='https://placeholder.co/500/500.png']"
---

## Hello, here's some listings with `image-lazy-loading: false`
7 changes: 6 additions & 1 deletion tests/docs/smoke-all/listings/image-lazy-loading/blog/index-grid.qmd
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Original file line number Diff line number Diff line change
Expand Up @@ -6,15 +6,20 @@ listing:
- title
- image
_quarto:
render-project: true
tests:
html:
ensureHtmlElements:
-
-
- "img[loading='lazy'][src='https://placeholder.co/100/100.png']"
- "img[src='https://placeholder.co/200/200.png']"
- "img[loading='lazy'][src='https://placeholder.co/300/300.png']"
- "img[loading='lazy'][src='https://placeholder.co/400/400.png']"
- "img[src='https://placeholder.co/500/500.png']"
- "img[loading='lazy'][src='https://placeholder.co/600/600.png']"
-
- "img[loading='lazy'][src='https://placeholder.co/200/200.png']"
- "img[loading='lazy'][src='https://placeholder.co/500/500.png']"
---

## Hello, here's some listings
25 changes: 16 additions & 9 deletions tests/docs/smoke-all/listings/image-lazy-loading/blog/index-table-eager.qmd
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Original file line number Diff line number Diff line change
Expand Up @@ -7,15 +7,22 @@ listing:
- image
image-lazy-loading: false
_quarto:
html:
ensureHtmlElements:
-
- "img[src='https://placeholder.co/100/100.png']"
- "img[src='https://placeholder.co/200/200.png']"
- "img[loading='lazy'][src='https://placeholder.co/300/300.png']"
-
- "img[loading='lazy'][src='https://placeholder.co/100/100.png']"
- "img[loading='lazy'][src='https://placeholder.co/200/200.png']"
render-project: true
tests:
html:
ensureHtmlElements:
-
- "img[src='https://placeholder.co/100/100.png']"
- "img[src='https://placeholder.co/200/200.png']"
- "img[loading='lazy'][src='https://placeholder.co/300/300.png']"
- "img[src='https://placeholder.co/400/400.png']"
- "img[src='https://placeholder.co/500/500.png']"
- "img[loading='lazy'][src='https://placeholder.co/600/600.png']"
-
- "img[loading='lazy'][src='https://placeholder.co/100/100.png']"
- "img[loading='lazy'][src='https://placeholder.co/200/200.png']"
- "img[loading='lazy'][src='https://placeholder.co/400/400.png']"
- "img[loading='lazy'][src='https://placeholder.co/500/500.png']"
---

## Hello, here's some listings with `image-lazy-loading: false`
7 changes: 6 additions & 1 deletion tests/docs/smoke-all/listings/image-lazy-loading/blog/index-table.qmd
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Original file line number Diff line number Diff line change
Expand Up @@ -6,15 +6,20 @@ listing:
- title
- image
_quarto:
render-project: true
tests:
html:
ensureHtmlElements:
-
-
- "img[loading='lazy'][src='https://placeholder.co/100/100.png']"
- "img[src='https://placeholder.co/200/200.png']"
- "img[loading='lazy'][src='https://placeholder.co/300/300.png']"
- "img[loading='lazy'][src='https://placeholder.co/400/400.png']"
- "img[src='https://placeholder.co/500/500.png']"
- "img[loading='lazy'][src='https://placeholder.co/600/600.png']"
-
- "img[loading='lazy'][src='https://placeholder.co/200/200.png']"
- "img[loading='lazy'][src='https://placeholder.co/500/500.png']"
---

## Hello, here's some listings
7 changes: 7 additions & 0 deletions tests/docs/smoke-all/listings/image-lazy-loading/blog/post-4.qmd
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@@ -0,0 +1,7 @@
---
title: Post 4
---

This is 4.

![](https://placeholder.co/400/400.png){.preview-image}
8 changes: 8 additions & 0 deletions tests/docs/smoke-all/listings/image-lazy-loading/blog/post-5.qmd
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@@ -0,0 +1,8 @@
---
title: Post 5
image-lazy-loading: false
---

This is 5.

![](https://placeholder.co/500/500.png){.preview-image}
8 changes: 8 additions & 0 deletions tests/docs/smoke-all/listings/image-lazy-loading/blog/post-6.qmd
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@@ -0,0 +1,8 @@
---
title: Post 6
image-lazy-loading: true
---

This is 6.

![](https://placeholder.co/600/600.png){.preview-image}
58 changes: 54 additions & 4 deletions tests/docs/smoke-all/listings/image-lazy-loading/listings.json
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@@ -1,18 +1,68 @@
[
{
"listing": "/blog/index.html",
"listing": "/blog/index-grid-eager.html",
"items": [
"/blog/post-1.html",
"/blog/post-2.html",
"/blog/post-3.html"
"/blog/post-3.html",
"/blog/post-4.html",
"/blog/post-5.html",
"/blog/post-6.html"
]
},
{
"listing": "/blog/index-eager.html",
"listing": "/blog/index-default.html",
"items": [
"/blog/post-1.html",
"/blog/post-2.html",
"/blog/post-3.html"
"/blog/post-3.html",
"/blog/post-4.html",
"/blog/post-5.html",
"/blog/post-6.html"
]
},
{
"listing": "/blog/index-table-eager.html",
"items": [
"/blog/post-1.html",
"/blog/post-2.html",
"/blog/post-3.html",
"/blog/post-4.html",
"/blog/post-5.html",
"/blog/post-6.html"
]
},
{
"listing": "/blog/index-grid.html",
"items": [
"/blog/post-1.html",
"/blog/post-2.html",
"/blog/post-3.html",
"/blog/post-4.html",
"/blog/post-5.html",
"/blog/post-6.html"
]
},
{
"listing": "/blog/index-default-eager.html",
"items": [
"/blog/post-1.html",
"/blog/post-2.html",
"/blog/post-3.html",
"/blog/post-4.html",
"/blog/post-5.html",
"/blog/post-6.html"
]
},
{
"listing": "/blog/index-table.html",
"items": [
"/blog/post-1.html",
"/blog/post-2.html",
"/blog/post-3.html",
"/blog/post-4.html",
"/blog/post-5.html",
"/blog/post-6.html"
]
}
]
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