Keep linked PDFs under 60 MB
SkillDocs & knowledgepdf-size is a skill for auditing websites that publish downloadable PDFs, such as reports, white papers, legal documents, and manuals. It checks whether a site links its PDF files correctly so they can be found and indexed. It applies to any site where PDFs are linked as indexable content resources.
Available today. Use it from your connected AI after setup.
No other account needed.
Have an AI agent that supports loading skills.
Then ask your AI: use the Keep linked PDFs under 60 MB skill
What your AI can do with it
- Checks whether a website links its downloadable PDF files correctly
- Verifies PDFs can be found and indexed
- Audits sites publishing reports, white papers, legal documents, and manuals
- Applies to any site where PDFs are linked as indexable content resources
Getting started
- Have an AI agent that supports loading skills.
- Add the pdf-size skill to the agent's available skills.
- Ask the agent to audit a site that publishes downloadable PDFs, and the skill will be used for the check.
What this skill tells your AI
The instructions your AI receives, as published by thedaviddias/front-end-checklist in skills/pdf-size/SKILL.md and read by ahel’s review.
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 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 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.
For full implementation details, code examples, and framework-specific guidance,
see references/rule.md.
Rule page: https://frontendchecklist.io/en/rules/seo/pdf-size
Signals
- GitHub stars
- 74k
- Forks
- 7k
- Last commit
- Aug 2026
Questions
- When should pdf-size be used?
- Use it when auditing a site that publishes downloadable PDFs, such as reports, white papers, legal documents, or manuals. It applies to any site where PDFs are linked as indexable content resources.
- What does the skill actually check?
- It checks whether a website links its downloadable PDF files correctly so they can be found and indexed.
Advanced
- Item type
- skill
- Key
pdf-size- Source
- github.com/thedaviddias/front-end-checklist