Pdf Size

Keep linked PDFs under 60 MB

PDFs larger than Googlebot's download threshold are partially crawled or skipped, meaning their content may not appear in search results even when linked from well-indexed pages.

Quick Reference

• Googlebot truncates files larger than 15 MB for crawling; 60 MB is a documented upper limit
• Large PDFs may be partially indexed or skipped entirely
• Compress PDFs before publishing: use PDF optimisation tools to reduce file size
• Add HTML landing pages alongside PDFs to ensure content is indexable

Check

Find all <a href='*.pdf'> links on the site. For each linked PDF, perform a HEAD request and check the Content-Length header. Flag any PDF exceeding 10 MB (recommend compression) or 15 MB (likely to be truncated by Googlebot).

Fix

Compress large PDFs using a PDF optimisation tool (Adobe Acrobat, Ghostscript, or Smallpdf). Remove embedded high-resolution images, fonts, and metadata not required for reading. If compression is insufficient, create an HTML page with the same content as the primary indexable version, and offer the PDF as a download.

Explain

Googlebot downloads and indexes the content of PDFs linked from your site. However, it has a file size limit for downloads — files beyond this limit are partially indexed or skipped. Large PDFs also slow down crawling and consume crawl budget. Keeping PDFs small ensures their full content appears in search results.

Code Review

Find all <a href> links with .pdf extension. For each PDF URL, perform a HEAD request and check Content-Length header value. Flag PDFs exceeding 10,485,760 bytes (10 MB) for compression review. Flag PDFs exceeding 15,728,640 bytes (15 MB) as at-risk for partial indexing. Verify PDF URLs return 200 status and appropriate Content-Type: application/pdf header.

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For full implementation details, code examples, and framework-specific guidance, see references/rule.md.

Rule page: https://frontendchecklist.io/en/rules/seo/pdf-size

Keep linked PDFs under 60 MB

Checks linked PDF sizes against Googlebot 60MB truncation limit

Priority: medium · Difficulty: intermediate · Time: 15 min

--- Google indexes PDFs and can show them directly in search results. However, very large PDF files may be truncated during download, resulting in partial indexing of the content, which is why large documents often need an accompanying HTML strategy rather than relying on the PDF alone.

Code Example

# Check a single PDF's size via HTTP header
curl -I https://example.com/docs/annual-report.pdf | grep -i content-length

# Check file size in bytes
# 1 MB = 1,048,576 bytes
# 10 MB = 10,485,760 bytes
# 60 MB = 62,914,560 bytes

Why It Matters

PDFs larger than Googlebot's download threshold are partially crawled or skipped, meaning their content may not appear in search results even when linked from well-indexed pages. That makes file-size control part of the same discoverability work as HTML companion pages and crawl-friendly document delivery.

Googlebot's Size Limits

Google has not published an exact byte limit, but has documented:

• Files above 15 MB may have crawling issues
• The practical upper limit is approximately 60 MB for content indexing
• Very large files are skipped or only the first portion is indexed

Size Targets

Compressing PDFs

Ghostscript (command line):

gs -sDEVICE=pdfwrite \
   -dCompatibilityLevel=1.4 \
   -dPDFSETTINGS=/ebook \
   -dNOPAUSE \
   -dQUIET \
   -dBATCH \
   -sOutputFile=compressed.pdf \
   original.pdf

PDF settings presets: /screen (72dpi), /ebook (150dpi), /printer (300dpi), /prepress (300dpi+)

Online tools:

• Adobe Acrobat (File → Reduce File Size)
• Smallpdf, ILovePDF, PDF24

HTML Companion Page Strategy

For critical content in large PDFs, create an HTML landing page:

<!-- HTML page for the PDF content -->
<article>
  <h1>Annual Report 2024</h1>
  <p>Key findings from our 2024 annual report...</p>
  <!-- full text content here -->
  <a href="/reports/annual-2024.pdf" rel="nofollow">
    Download PDF (8.2 MB)
  </a>
</article>

The HTML page is indexed fully; the PDF link uses rel="nofollow" if you don't need the PDF itself indexed separately.

PDF SEO Best Practices

• Add metadata (Title, Author, Subject) to the PDF properties
• Ensure the PDF is not password-protected or encrypted
• Use descriptive file names: annual-report-2024.pdf not doc123.pdf
• Avoid scanned PDFs without OCR — the text is an image and can't be indexed

HTML pages almost always outrank PDFs for the same content. If a PDF contains important content you want to rank, consider creating an HTML version as the primary page and offering the PDF as a supplementary download.

Exceptions

• Necessary utility or compliance pages can be intentionally brief and should not be judged by the same editorial-depth expectations as ranking-focused content.
• AI-assisted drafting is not a failure by itself; flag unsupported claims, missing editorial review, or low-originality output instead.
• When a page has both trust-signal issues and crawl/index problems, make the page eligible to rank first and then improve the content quality signals.

Verification

Automated Checks

• Inspect rendered HTML and HTTP headers to confirm the expected metadata or crawlability signal is present.
• Test the affected URL with Google Search Console or equivalent tooling where relevant.
• Re-crawl a representative page set after deployment.

Manual Checks

• Confirm the change does not create conflicting canonical-url, robots, or structured-data signals.