FreePDF Tag Check API — check a PDF against PDF/UA-1
Validate a PDF's accessibility tagging and get back the specific rules it fails.
PDF Tag Check validates a document against the PDF/UA-1 profile and returns the rules it fails, with the clause and test number for each. It reports a `verdict` and, importantly, how that verdict was reached: `validated_by: "verapdf"` means a full conformance check ran, while `validated_by: "structural"` means only structural evidence was available — the tag tree, the /MarkInfo flag, the document language, the title and any PDF/UA claim in the metadata. A structural check can prove a document *fails* (a PDF with no tag tree at all cannot conform) but never that it passes, so a conformance verdict is only ever issued on a real veraPDF pass. Free, and it never modifies the file.
How does the PDF Tag Check API work?
One HTTP request from any language. Every ASHDOCS endpoint uses the same X-API-Key header.
curl -X POST 'https://api.ashdocs.com/api/v2/tools/pdf-tag-check' \ -H 'X-API-Key: ash_live_...' \ -F 'file=@document.pdf'
Common use cases
- →Checking a document before publishing it under an accessibility obligation
- →Auditing a back catalogue for untagged PDFs
- →Verifying that a generated PDF kept its tag tree
Frequently asked questions
How much does the PDF Tag Check API tool cost?+
Nothing — this is a local page operation with no rendering engine, OCR or AI behind it, so it runs free on every plan. Sandbox keys (prefix ash_test_) also never consume credits.
What is the endpoint URL for this tool?+
The endpoint is documented in the curl example on this page. All ASHDOCS endpoints share the base URL https://www.ashdocs.com and require an X-API-Key header.
Can I run this tool inside Make, Zapier, or n8n?+
Yes — through each platform's built-in HTTP mechanism (Make's HTTP module, Webhooks by Zapier, n8n's HTTP Request node). Nothing to install: point it at this exact endpoint with your X-API-Key header. See /integrations/make, /integrations/zapier or /integrations/n8n for step-by-step setup.
Does this tool support batch or scheduled runs?+
Yes. POST /api/v1/batch runs any tool over up to 50 files with a single credit ledger entry, and pipeline schedules let you trigger the same tool on a cron. Both are documented in /docs.