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Accessibility · Canvas LTI

The Canvas accessibility scanner that fixes things.

Scans pages, assignments, discussions, files, quizzes, rubrics, and PPTX. Real WCAG contrast math. Broken link detection. Accessible HTML export for students. Score trends over time. Auto-scan scheduling. AI-optional — every feature works without it. Capped at 10 courses per install. No implementation fee.

BIO 101 · Course-wide scan
14
Critical
31
Warning
3
Broken links
18
Cognitive
💡 Smart Fix · alt text
"Diagram showing the four stages of cell division: prophase, metaphase, anaphase, and telophase."
YouTube video — captions verified ✓
via API
Contrast ratio 2.4:1 — below WCAG AA (4.5:1)
Week3.html
Quiz Q4: image missing alt text
Midterm Quiz
Slide 7: no title placeholder (PPTX)
Lecture3.pptx
🔧
AI optional. Everything works without it.
Every fix suggestion, every scan, every report works with zero AI configuration. Connect an Anthropic API key to upgrade suggestions to Claude-generated context-aware fixes — but it's never required. UDOIT tells you what's broken and makes you fix it manually. Holon fixes it for you, with or without AI. AI enhances, never gatekeeps
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Per-install, 10-course cap
Each license covers one Canvas install and scans up to 10 courses. This is a per-tool license — not a campus-wide contract. Need more courses? Purchase additional licenses or contact us for volume pricing. Installs in under 2 minutes via LTI 1.1 XML.

How it compares

Feature-by-feature against UDOIT Advantage — the current market leader.

Feature Holon Accessibility UDOIT Advantage Anthology Ally
Pages, assignments, discussions, syllabus scan
PDF & DOCX content scanning✓ deep✓ basic
PPTX scanning (slide titles, image alt, notes)
Quiz question body scanning✗ intro only
Rubric accessibility scanning
Real WCAG contrast ratio math (hex/rgb)✓ exact ratios
ARIA & keyboard heuristics
Broken external link detection
Real YouTube/Vimeo caption verification✓ via API✗ flag only✗ flag only
Cognitive load / Flesch-Kincaid checks
Fix applied back to Canvas (not just guided)✓ one-click✗ guide only✗ guide only
Fix suggestions for every issue type✓ all types✗ limited
AI-enhanced fix suggestions✓ optional✓ alt text
Bulk fix (same image/link across all content)
Accessible HTML export for students✓ public URL✓ many formats
Score trend over time✗ rescan only
Auto-scan scheduling✓ daily/weekly/monthly
Narrative accessibility report (shareable)
Issue resolution tracking (won't fix, resolved)
Account-wide dashboard (all courses)✓ free✗ paid tier
Self-install via LTI XML (2 minutes)✗ IT required✗ IT required

Everything in Holon Accessibility

Every feature listed here is shipping today.

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Full WCAG 2.1 Scanner
Scans every page, assignment, discussion, announcement, and syllabus body. Checks alt text, link text, heading hierarchy, table structure, color contrast, empty content, ARIA attributes, and keyboard accessibility.
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Real Color Contrast Math
Parses hex, rgb, and named colors from inline styles. Computes the actual WCAG relative luminance ratio. Reports the exact number (e.g., "2.4:1 — below 4.5:1 AA minimum") not just a vague flag. Flags severe failures as critical.
vs. UDOIT: exact ratios, not guesses
⌨️
ARIA & Keyboard Heuristics
Catches positive tabindex values (breaks tab order), click handlers on non-interactive elements, duplicate IDs, empty aria-labels, broken aria-labelledby references, and form inputs without labels. Six checks UDOIT doesn't do.
vs. UDOIT: not available
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Broken Link Detection
Checks every external link in course content via HTTP HEAD requests. Flags 404s, 410s, 403s, and timeouts as critical issues with the specific URL and location. Results cached 6 hours. No other Canvas accessibility tool does this.
vs. UDOIT: not available
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PPTX Scanning
Opens PowerPoint files as ZIP archives and parses slide XML. Checks per-slide title presence, image alt text (descr attribute), speaker notes coverage, document title metadata, and reading level on extracted text. The only Canvas tool that scans PPTX.
vs. UDOIT: not available anywhere
Quiz Question Scanning
Hits the Canvas quiz questions API and runs full WCAG checks on every individual question body and answer choice HTML — not just the quiz intro text. Catches missing alt text in question images, vague links, and contrast issues inside quiz content.
vs. UDOIT: intro text only
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Rubric Accessibility Scanning
Scans rubric criteria for vague language ("good," "okay," "satisfactory"), high reading level, and empty rating descriptions. Specific, measurable criteria help students with cognitive disabilities understand expectations. No other tool scans rubrics.
vs. UDOIT: not available anywhere
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PDF & DOCX Deep Scanning
Reads actual file content — not just metadata flags. Detects scanned-image PDFs with no text layer, missing title/language metadata, missing heading structure, and untagged documents. Runs DOCX content through the same WCAG checks as HTML pages.
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Smart Fix Suggestions (No AI Required)
Every issue type has a rule-based smart suggestion — heading rewrites, link text from URL, contrast alternatives, ARIA fixes, PPTX guidance, rubric improvements. Connect an Anthropic API key for Claude-powered context-aware suggestions. AI enhances; nothing is gated behind it.
vs. UDOIT: guide only, no suggestions
One-Click Fix Apply
Accept a suggestion and Holon writes the fix directly back to Canvas via the API. Alt text, link text, table headers — applied instantly. Every fix is logged with timestamp and user for compliance audit trails.
vs. UDOIT: instructors fix manually
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Bulk Fix
The same image appearing on 8 pages? Fix its alt text once and Holon applies it everywhere. Groups fixable issues by image src or link href so a single decision covers all instances across the entire course.
vs. UDOIT: not available
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Cognitive Load Checks
Beyond WCAG: Flesch-Kincaid grade level, long-sentence detection (over 35 words), passive-voice density. Flags graduate-level reading in undergraduate courses. Ahead of WCAG 3.0's cognitive accessibility guidelines; no competitor ships this.
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Real Caption Verification
Hits YouTube and Vimeo APIs to verify captions actually exist on embedded videos. Verified videos get a green ✓ and are downgraded to a suggestion. Videos confirmed to have no captions are escalated to critical. Not "please verify" — actually verified.
Accessible HTML Export
Convert any PDF, DOCX, or PPTX to a clean, screen-reader-optimized HTML page. Students get a public URL — no login required. Works immediately after conversion. Includes skip links, semantic structure, and dark mode support.
vs. UDOIT: not available
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Score Trends Over Time
Every scan is stored. The Trends tab shows your course's accessibility score across all scans as a line chart — first score, latest score, total improvement, and scan count. Prove progress to your disability services office.
vs. UDOIT: rescan only, no history
Auto-Scan Scheduling
Set a daily, weekly, or monthly auto-scan and forget it. The scheduler runs in the background, stores results, and keeps your trend chart current without any manual effort. No other Canvas accessibility tool offers automatic scheduling.
vs. UDOIT: manual only
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Narrative Accessibility Report
Generates a plain-English 3-paragraph summary of your course's accessibility status, top issues, and recommended fixes — suitable for sharing with a department chair, disability services office, or ADA coordinator. Copy with one click. AI-enhanced when a key is available.
vs. UDOIT: raw data table only
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Compliance Report
One-click printable report with course score, per-item scorecard, complete fix audit log, severity breakdown, and a sign-off section for legal attestation. Save as PDF directly from your browser. Print to PDF for ADA documentation.
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Per-Item Scoring
Every page, assignment, file, and quiz gets its own 0–100 accessibility score weighted by issue severity. Sort by score to surface your worst content first. Fix the bottom 10% and your course-wide score jumps significantly.
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Account-Wide Dashboard
Scan every course you teach in one pass. See per-course scores, identify your worst courses, track total issues across all courses. Free in every tier. UDOIT Advantage gates this behind a paid enterprise tier.
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PDF → Canvas Page Conversion
Converts PDF and DOCX files into accessible Canvas Pages with semantic heading detection, proper paragraph structure, and auto-publication controls. Replaces an inaccessible file with accessible HTML right inside Canvas.

Ready to leave UDOIT behind?

5-day free trial. No credit card. No implementation fee. Installs in Canvas in under 2 minutes via LTI XML.

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