Most organizations discover the hard way that auto-generated ALT text — whether from Adobe Acrobat's built-in auto-tagging tool or a general-purpose AI — produces descriptions that are technically present but functionally hollow. For instance, a chemistry diagram labeled simply as "Image of a chart" may satisfy a basic compliance checklist, but it fails the reader. While such metadata technically "passes" an automated inspection, it offers no real value and leaves your organization vulnerable to accessibility gaps and their repercussions.
SunTec Digital bridges this divide, transforming static images into descriptions that are genuinely readable by assistive technology, defensible against WCAG 2.2, ADA, Section 508, and PDF/UA audits, and indexed more accurately by search engines.
Our ALT text services combine a context-aware AI engine — one that reads the headings, captions, and body text around each image to determine its role on the page — with domain-trained subject matter experts who verify accuracy for complex visuals like STEM figures, financial charts, and annotated diagrams. The output is a description of what the image means within your document.
Context Over Captions
Generic ALT text creation tools describe images as standalone objects. Our process reads the full page environment — headings, body text, captions, table references — to determine an image's purpose before generating descriptions.
Domain-Trained Reviewers, Not Just Proofreaders
Every auto-generated description flagged as medium- or high-complexity passes through a subject matter expert with relevant domain knowledge and sufficient context.
Built for Backlogs and Ongoing Production
Whether you’re clearing a backlog of 200 legacy PDFs before a deadline or integrating accessibility into your daily publishing workflow, our quality remains high at any scale.
Our ALT text writing services are calibrated against the accessibility standards that matter to publishers operating in regulated markets.
ADA (Americans with Disabilities Act)
Title II and Title III requirements for public-facing digital documents.
Section 508 (Rehabilitation Act)
Technical requirements for electronic content produced by or for U.S. federal agencies and their partners.
WCAG 2.2 (Web Content Accessibility Guidelines)
The current W3C standard for digital content accessibility, covering text alternatives at Level A, AA, and AAA.
PDF/UA (ISO 14289)
The ISO standard specifically governing accessible PDF structure, tagging, and assistive technology compatibility
EAA (European Accessibility Act)
EU Directive 2019/882, setting accessibility requirements for products and services in European markets.
AODA (Accessibility for Ontarians with Disabilities Act) / ACA (Accessible Canada Act)
Canadian federal and provincial accessibility mandates.
Not every PDF library needs the same level of intervention. We've structured our services around the distinct PDF ALT text requirements so the scope of work matches your actual situation and delivers the best possible solution.
Most ALT text writing service workflows are two steps: run the AI, deliver the file. That speed comes at the cost of accuracy on complex visuals, consistency across large libraries, and defensibility under audit. Our process adds the stages that close those gaps — calibration, classification, contextual drafting, expert validation, and screen-reader-tested QC — without sacrificing turnaround.
We begin by establishing the rules as per your internal style guide, target compliance standard (WCAG 2.2, PDF/UA, ADA, Section 508), document purpose, and audience profile. These parameters become the baseline instructions for both our AI engine and our human reviewers, ensuring every description aligns with your brand voice and regulatory requirements.
Each document's visual assets are categorized into complexity tiers — simple (icons, decorative borders), moderate (photographs, basic charts), and complex (multi-panel STEM figures, data-dense visualizations, annotated schematics). Decorative or non-informative elements are tagged as artifacts, so the AI focuses its effort on images that carry meaning. Very complex visuals are pre-flagged for mandatory expert review.
Our AI engine extracts each visual from the PDF's content layer and reads the surrounding signal — adjacent headings, captions, body text, and table references — to determine the image's role within the narrative. It then produces a first-pass description that is anchored to the page context.
SMEs review every flagged item and audit a random sample of the descriptions. Ambiguous, data-heavy, or technically nuanced images are rewritten or corrected to ensure contextual and factual accuracy. Where image extraction quality is poor — due to low-resolution scans, merged backgrounds, or cropped borders — reviewers manually repair the output.
We scan every description for voice consistency and eliminate robotic or repetitive phrasing. Spot-check validation is performed with industry-standard screen readers (JAWS, NVDA) to confirm that the reading experience works as intended. Final delivery includes documentation confirming compliance with your mandated standard.
Generic ALT text services treat every image the same way, regardless of what it contains or who it's for. That works until you need someone to accurately describe a multi-panel STEM figure, or write a description of a children's textbook illustration that serves a specific learning objective, or interpret a financial chart where misrepresenting a single data point changes the meaning. Our ALT text services account for the unique needs of diverse publishing verticals, ensuring truly accessible reading experiences for your audience.
Most publishers assume their tagged PDFs are compliant — until an audit reveals otherwise. Don’t wait for that compliance penalty to hit your publishing workflow. Request a free sample audit of your media library and evaluate the difference our ALT text services can make — in accuracy, in screen reader usability, and in regulatory defensibility — before any engagement begins.
Get in TouchALT text services add alternative text descriptions to every meaningful visual element in a PDF — images, charts, graphs, diagrams, formulas — so that screen readers and other assistive technologies can convey their meaning to users who cannot see them. Beyond accessibility compliance, well-written ALT text also improves search engine indexing, since search crawlers rely on text descriptions to understand visual content.
Turnaround depends on three factors: total page count, the proportion of complex visuals requiring expert review, and your target compliance standard. We can provide a closer estimate of the cost for our image ALT text services if you share your requirements with us at info@suntecdigital.com.
We sign NDAs before any document exchange and do not retain files on our systems after delivery. SunTec Digital operates under documented data-handling protocols aligned with enterprise security standards. For publishers in regulated industries, our security documentation is available for review before engagement.
Yes. Whether you publish through a content management system, an automated pipeline, or a templated production workflow, we can connect ALT text generation and compliance checks as a native step in your process.
Our ALT tag writing services calibrate outputs to WCAG 2.2 (Levels A, AA, and AAA), Section 508, PDF/UA (ISO 14289), ADA (Titles II and III), the European Accessibility Act, AODA, and the Accessible Canada Act. Your target standard is established during project setup and used to govern all outputs during QC.
info@suntecdigital.com
+44 203 514 2601
+1 585 283 0055
