mozilla/pdf.js · error · Error

extractPages: too many pageIndices.

Error message

extractPages: too many pageIndices.

What it means

Plain Error thrown when an image-type pageInfo supplies pageIndices with more than one entry. A single image produces exactly one synthetic page, so multiple target slots are meaningless.

Source

Thrown at src/core/editor/pdf_editor.js:1023

        task,
        newAnnotationsByPage: getNewAnnotationsMap(annotationStorage),
        imagesPromises: AnnotationFactory.generateImages(
          annotationStorage.values(),
          this.xrefWrapper,
          true
        ),
      };
    }

    const imageEntries = [];
    for (const pageInfo of pageInfos) {
      const { document, image, includePages, excludePages, pageIndices } =
        pageInfo;
      if (image) {
        if (pageIndices) {
          newIndex = -1;
          if (pageIndices.length > 1) {
            throw new Error("extractPages: too many pageIndices.");
          }
        }
        // Image entries are inserted as synthetic pages. Reserve a slot now;
        // the actual page dict is built after real pages are collected so
        // that we know the modal MediaBox dimensions to use.
        let newPageIndex;
        if (pageIndices?.length) {
          newPageIndex = pageIndices[0];
        } else if (newIndex !== -1) {
          newPageIndex = newIndex++;
        } else {
          for (
            newPageIndex = 0;
            this.oldPages[newPageIndex] !== undefined;
            newPageIndex++
          ) {
            /* empty */
          }

View on GitHub (pinned to 5903d58d58)

Solutions

1. For image pageInfos, omit pageIndices (auto-assign) or supply exactly one index.
2. Validate that image entries have pageIndices.length <= 1 before calling extractPages.
3. If you need the image at a specific slot, pass pageIndices: [targetSlot].

Example fix

// before
pageInfos = [{ image: myBitmap, pageIndices: [3, 4] }];

// after
pageInfos = [{ image: myBitmap, pageIndices: [3] }];
// or auto-assign:
pageInfos = [{ image: myBitmap }];

for (const p of pageInfos) {
  if (p.image && p.pageIndices && p.pageIndices.length > 1) {
    throw new Error('Image pageInfos may have at most one pageIndex.');
  }
}

try {
  await editor.extractPages(pageInfos, ...);
} catch (e) {
  if (e.message === 'extractPages: too many pageIndices.') {
    pageInfos = pageInfos.map(p => p.image ? { ...p, pageIndices: p.pageIndices?.slice(0, 1) } : p);
    return editor.extractPages(pageInfos, ...);
  }
  throw e;
}

When it happens

Trigger: Passing { image, pageIndices: [3, 4] } to extractPages—two slots for one image.

Common situations: Caller builds pageInfos generically from a list and accidentally attaches multi-element pageIndices to image entries.

Related errors

• extractPages: partial pageIndices cannot be combined with in
• extractPages: invalid page index.
• extractPages: overlapping pageIndices.
• extractPages: nothing to extract.
• extractPages: sparse pageIndices.

AI-assisted analysis of mozilla/pdf.js@5903d58d58 (2026-08-13). Data as JSON: /api/errors/3a5d7d843b93d1f8. Report an issue: GitHub.