Explore Free Online PDF Accessibility Tools

Making PDFs accessible can be slow and repetitive. This guide shows how to use PDFix’s free web tools to validate against PDF/UA, auto-fix common issues, and auto-tag untagged PDFs – plus when to switch to PDFix Desktop or SDK for scale.

What “Accessible PDF” Means and Why It Matters

PDF/UA (ISO 14289-1) defines how tagged PDF must be authored to be accessible for assistive tech.
WCAG provides outcome-based web guidelines; PDF techniques map to tagging and reading order.
Tagged PDF adds a semantic structure tree (headings, lists, tables, figures, alt text)

the picture of unstructured pdf document transforming to structured accessible pdf with tag tree

1. Validate PDF/UA

Go to pdfix.io/validate-pdf-ua – upload a file, review the validation report powered by veraPDF validation profiles.
What’s checked: machine-verifiable PDF/UA rules; human checks still needed (e.g., logical reading order quality, alt text accuracy).

2. Auto-Fix Validation Errors

Open pdfix.io/autofix and apply automatic corrections based on the report; re-validate.

3. Make Untagged PDFs Accessible (Auto-Tag)

Use pdfix.io/make-pdf-accessible to generate an initial tag tree – headings, paragraphs, lists, tables, images.
Finish with a quick manual review of tags / reading order.

4. Convert PDF to HTML

Use pdfix.io/convert-pdf-to-html to convert PDFs to fixed / responsive HTML.
For tagged PDFs we preserve structure; for untagged files we can auto-tag first or export visual HTML without semantics.

When to Use PDFix Desktop or SDK

PDFix Desktop Lite (free): free PDF validation with veraPDF
PDFix Desktop Pro: automated PDF remediation, batch processing, validator built-in.
PDFix SDK: integrate PDF accessibility – auto-tagging, validation, and batch fixes – into document pipelines.

Example: Make a PDF Accessible via CLI (SDK)

Typical workflows

1. Image-only PDF → OCR → Make Accessible

# 1) Run OCR first (required for image-only PDFs)
./pdfix_app ocr -i input.pdf -o ocr.pdf

# 2) Convert to a compliant PDF/UA
./pdfix_app make-accessible -i ocr.pdf -o accessible.pdf

2. Add tags only (keep your existing PDF, add a tag tree)

./pdfix_app add-tags -i input.pdf -o tagged.pdf

Why PDFix?

Standards-aligned validation (veraPDF engine) and actionable reports.
Automation options: Web tools, Desktop batch features, SDK/CLI, and Batch Actions via JSON.
Scales from single files to pipelines with developer-friendly docs and examples.

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Pricing

Frequently Asked Questions

What is PDF/UA?

PDF/UA (ISO 14289-1) is the international standard for accessible PDF files. PDFix supports creating and validating PDF/UA compliance across PDFix Desktop, SDK, and free online tools.

How can I check a PDF for accessibility online?

Upload your file to the Validate PDF/UA tool on pdfix.io. It runs veraPDF validation to test against ISO 14289 rules and returns a machine-readable report. No sign-up required.

Does validation guarantee full accessibility?

No. PDFix validation verifies machine-checkable rules. Human review is still required to confirm logical reading order and alt-text quality. See PDF Validation overview.

How do I auto-tag an untagged PDF?

You can use the free Make PDF Accessible tool to automatically generate a tag tree – headings, paragraphs, lists, tables, and figures – and convert your document into a structured, accessible PDF.

For large-scale processing, PDFix Desktop provides the same functionality with batch automation.
See our easy step-be-step guide: How to Make a PDF/UA-Compliant PDF in Minutes with PDFix Desktop ›

Developers can also use the PDFix SDK CLI commands.

Can I fix PDF/UA errors automatically?

Yes. Upload your file online to pdfix.io/autofix or run the Auto-fix tool in PDFix Desktop after validation to resolve machine-detectable issues. Re-validate to confirm the fixes.