Alto
AI-Native Document Accessibility

Make every public PDF compliant.

Brief Alto with any PDF. We add a tag tree, AI-generated alt text, language and PDF/UA-1 metadata in seconds — with an independent veraPDF conformance report as proof.

Drop a file anywhere in this box · max 50 MB, 200 pages

Free account required — takes 10 seconds

Our proven approach to PDF/UA-1 compliance.

We combine heuristic audits, AI-powered remediation, and independent veraPDF validation to deliver PDF/UA-1 conformant output that screen readers actually use and legal teams can verify.

AI-Powered Remediation

Inject a real struct tree with MCID-linked marked content, embed fonts, set metadata, and generate alt text with Claude — automatically, no manual tagging.

Real PDF/UA-1 Structure

Every output ships /StructTreeRoot with /Document, /ParentTree, XMP pdfuaid identifier, and /Scope on TH cells — every fixable ISO 14289-1 clause.

Independent veraPDF Proof

Each file is re-validated by veraPDF — the canonical open-source validator used by Adobe and Foxit. You get a pass/fail verdict you can hand to legal.

How it Works

Audit it. Fix it. Prove it.

sample.pdf
10/100
7.1.3Content not tagged as real content
6.2.1MarkInfo missing
7.1.11No /StructTreeRoot
7.2.34Language unspecified
7.1.10DisplayDocTitle false
6 failed rules · 56 failed checks
Step One

Audit your PDF

We run every page through veraPDF and a heuristic auditor. You see every failed ISO 14289-1 clause and its severity before we touch a byte.

Tagging content…
/StructTreeRoot
└─ /Document
├─ /H1 "Quarterly…"
├─ /P ×7
├─ /Figure /Alt="…"
└─ /Table → /TR → /TH ×3
Generating alt text · image 2 of 282%
Step Two

Fix it automatically

We inject a real struct tree with MCID-linked marked content, embed fonts, set metadata, and call Claude to write specific alt text for every image.

veraPDF 1.28 · ua1
PASS
Compliant106/106
PDF/UA-1 · ISO 14289-1
Rules
106 / 106
Checks
2038 / 2038
Step Three

Ship with proof

Every output is re-validated by veraPDF before you see it. You get a 106/106 conformance report and a remediated PDF ready to hand to legal.

Deadline

ADA Title II compliance begins April 2026.

Title II of the Americans with Disabilities Act requires state and local government digital content — including public-facing PDFs — to meet WCAG 2.1 Level AA. Large entities must comply by April 24, 2026; small entities by April 26, 2027. Start remediating now — with proof.

AI Image Analysis

Describe every image with AI — not placeholder text.

Claude analyzes each image in your PDF and writes specific, screen-reader-ready alt text. A bar chart gets described as a bar chart — not 'Image 1'. Every description is embedded directly in the /Figure tag's /Alt attribute.

Alto · Alt Text Generator
/Figure · Image XObject
Claude · claude-sonnet-4-6

"A bar chart titled 'Quarterly Issue Counts' displaying five bars of varying heights, with the third quarter showing the highest count."

/Altembedded in /Figure struct element
LOGO
"A green rectangular banner displaying the company name..."
Done

Structural Remediation

Build a real tag tree — not just metadata patches.

We inject marked content with MCIDs into every content stream, build a /StructTreeRoot with /ParentTree, and tag tables as /Table → /TR → /TH|/TD with proper /Scope. Headings are promoted by font size. Every page gets /StructParents. Real structure, not shortcuts.

Alto · Tag Tree Inspector
/StructTreeRoot
└─/Document
├─/H1"Quarterly Accessibility Report"
├─/H2"Findings and Recommendations"
├─/P×7 paragraphs
├─/Figure/Alt="A bar chart..."
├─/Figure/Alt="A green banner..."
└─/Table
├─/TR→ /TH ×3 /Scope=Column
├─/TR→ /TD ×3
├─/TR→ /TD ×3
└─/TR→ /TD ×3
24 struct elements·2 pages tagged·2 /Alt generated

Compliance Proof

Ship with veraPDF proof — not your own checker.

Every remediated PDF is independently validated against ISO 14289-1 by veraPDF before you see it. 106/106 rules, 2038 checks passed — the same open-source validator Adobe and Foxit use. Hand the report to legal.

veraPDF 1.28 · PDF/UA-1 Report
PASS
ISO 14289-1 Verdict
PDF/UA-1 Compliant
106
of 106 rules
cl. 7.1
4/4
General structure
cl. 7.2
1/1
Text content
cl. 7.4
3/3
Headings
cl. 7.5
2/2
Tables
cl. 7.21
1/1
Fonts
cl. 5/6
4/4
Metadata & MarkInfo
Total checks2038 / 2038 passed
Why Alto

How We Stand Out
from Manual Remediation.

Most teams still hand-tag PDFs in Acrobat or hire consultants. Alto delivers PDF/UA-1 compliant output automatically — with proof — in seconds.

Manual / Other Tools

Manual tagging in Acrobat Pro
Generic metadata injection
No independent validation
Per-page or hourly consulting
Weeks of back-and-forth revisions
Alto
Automated struct tree with MCIDs
AI-generated alt text via Claude
Independent veraPDF proof (106/106)
Flat pricing — unlimited pages
Compliant in seconds, not weeks
FAQ

Frequently Asked Questions.

Get Started

Ready to make your PDFs compliant?

Upload any PDF and get a PDF/UA-1 conformant version in seconds — with an independent veraPDF proof you can hand to legal.

EDUCATION
STUDENT HANDBOOKS
K-12 · University
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GOVERNMENT
PUBLIC NOTICES
City · County · State
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FINANCE
BUDGET REPORTS
Annual · Quarterly
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HEALTHCARE
PATIENT FORMS
HIPAA compliant
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LEGAL
COURT FILINGS
ADA Title II
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HR
POLICY MANUALS
Onboarding · Benefits
LEARN MORE
TRANSIT
ROUTE SCHEDULES
Bus · Rail · Ferry
LEARN MORE
PARKS & REC
PROGRAM GUIDES
Seasonal · Events
LEARN MORE
PLANNING
ZONING DOCUMENTS
Permits · Maps
LEARN MORE
LIBRARY
CATALOG REPORTS
Collection · Access
LEARN MORE
EDUCATION
STUDENT HANDBOOKS
K-12 · University
LEARN MORE
GOVERNMENT
PUBLIC NOTICES
City · County · State
LEARN MORE
FINANCE
BUDGET REPORTS
Annual · Quarterly
LEARN MORE
HEALTHCARE
PATIENT FORMS
HIPAA compliant
LEARN MORE
LEGAL
COURT FILINGS
ADA Title II
LEARN MORE
HR
POLICY MANUALS
Onboarding · Benefits
LEARN MORE
TRANSIT
ROUTE SCHEDULES
Bus · Rail · Ferry
LEARN MORE
PARKS & REC
PROGRAM GUIDES
Seasonal · Events
LEARN MORE
PLANNING
ZONING DOCUMENTS
Permits · Maps
LEARN MORE
LIBRARY
CATALOG REPORTS
Collection · Access
LEARN MORE