NV Access
Blind and low-vision people install NV Access's free, open-source NVDA screen reader to navigate Windows when commercial screen readers cost over a thousand dollars -- while web developers adopt it as a testing tool to catch accessibility failures before launch.
ENABLE Model location
What it is
NVDA (NonVisual Desktop Access) is a free, open-source screen reader for Microsoft Windows, developed by NV Access, a non-profit founded in 2007 by Michael Curran and James Teh -- both blind Australian software developers who met as teenagers at a music camp for blind children in Mittagong, New South Wales.1 Curran began building NVDA in April 2006 while studying at Monash University because the dominant commercial screen reader, JAWS, costs between $90 and $1,475 per year depending on the license -- more than many of the computers it runs on.2 "Why do blind people have to pay so much when many of them are unemployed?" Curran asked.1
In 2008, a grant from the Mozilla Foundation allowed Teh to work full-time on NVDA, a turning point that accelerated development from a side project into a viable assistive technology.3 By 2024, NVDA had become the most commonly used screen reader worldwide: the WebAIM Screen Reader User Survey #10, with 1,539 respondents, found 65.6% of screen reader users reported using NVDA, surpassing JAWS at 60.5%.4 The software is used by over 250,000 people across 175 countries, translated into more than 55 languages by volunteers.1
NVDA also serves a builder-side function: web developers use NVDA as a QA testing tool to verify that their sites work with screen readers before shipping. Harvard Digital Accessibility Services, WebAIM, and the American Foundation for the Blind all publish NVDA testing guides. Because NVDA interprets web markup strictly -- it will not use heuristics to compensate for missing ARIA labels or broken heading structures the way JAWS sometimes does -- it exposes exactly the barriers a blind user would encounter.5
NV Access is funded through corporate grants (Mozilla, Microsoft, Google, Adobe), individual donations, and accessibility consulting services. The software itself remains free. This funding model makes NVDA available to anyone with a Windows computer, but it also makes the tool that addresses precarity itself precarious -- dependent on the continued generosity of the corporations whose products it exists to compensate for.
Why it matters
A screen reader is how a blind person uses a visual operating system. Using one is not itself a compensation -- it is the equivalent of a monitor for sighted users. But the conditions around screen reader access are where the ENABLE Model's taxonomy applies. When a capable screen reader costs $1,475 per year, the price is a barrier. When an operating system ships with a built-in reader that only 0.7% of blind users choose as their primary tool, that built-in option is inadequate.4 When websites ship without semantic markup, even the best screen reader can only render what builders provide. NVDA sits at the intersection of these conditions: it is the free assistive technology that 65.6% of the world's screen reader users rely on, and it is the QA testing tool developers use to discover whether their sites are accessible at all.
The cost barrier is a force that disables: Before NVDA, a blind person who couldn't afford JAWS had almost no way to use a Windows computer independently. JAWS's licensing fees -- which can reach $3,000 in some European markets -- meant that the price of digital participation was higher for blind people than for sighted people, a structural expression of precarity.2 NVDA eliminated that cost barrier entirely. Its geographic adoption tells the story: in North America, where institutional licenses and vocational rehabilitation programs subsidize JAWS, it still leads (55.5% primary usage vs. NVDA's 24.0%). But in Europe, NVDA leads (37.2% vs. 29.7%). In Asia, NVDA dominates (70.8% vs. 22.9%). In Africa and the Middle East, it is the default (69.9% vs. 23.3%).4 Where money is scarce, NVDA is how blind people get online.
The tool compensates for absent care: NVDA does not fix inaccessible websites. It gives blind users a way to attempt them. When a site ships with unlabeled buttons, missing headings, or keyboard traps, NVDA renders whatever semantic information exists -- and exposes whatever is missing. The WebAIM survey found that 71.6% of screen reader users navigate web pages by headings.4 When a page has no heading structure, that navigation collapses. Users are forced into workarounds: tabbing through every element, guessing at unlabeled controls, or abandoning the site entirely. NVDA is the reason access is possible; inaccessible design is the reason it's laborious.
The founders built from lived experience: Curran and Teh did not design for blind people -- they designed as blind people. Teh studied software engineering at Queensland University of Technology, where Professor Malcolm Corney described diagrams aloud so he could follow lectures. Curran lost his remaining vision at 15. Their collaboration is an instance of disability expertise driving development: the tool works because its creators live with the problem it solves.
The testing paradox: When developers use NVDA to test their sites, they are using a navigator-side compensation as a builder-side tool. This is appropriate -- testing with actual assistive technology is genuine care. But the paradox is that NVDA's strict markup interpretation, which makes it excellent for compliance testing, can understate what real users experience. A developer tests a clean page; a blind user navigates a messy one, with pop-ups, dynamic content, and third-party widgets that no one tested.5
Running NVDA does not make a sighted developer a screen reader tester. A developer can verify that headings exist, that buttons are labeled, and that focus order is logical -- but they cannot replicate the cognitive model of someone who navigates by sound alone. Screen reader users develop spatial memory, listening shortcuts, and navigation heuristics that no testing checklist captures. Developer testing with NVDA catches markup failures; it does not catch experience failures. Organizations that treat developer screen reader testing as a substitute for testing with blind users are replacing one form of absent care with another.
Real-world examples
Blind inventors revolutionize computer access (October 2010)
-- Phys.org
- Michael Curran and James Teh won the "Les is More" award on ABC's New Inventors television show for NVDA. At the time, NVDA had over 50,000 downloads in 27 languages. The article noted that commercial screen readers cost more than $1,000 -- a cost that NVDA eliminated entirely. The award recognized what a Mozilla Foundation grant had made possible: a full-time development effort that turned a student project into the world's leading screen reader.
Adobe and NVDA Partnership Improves Accessibility (2012)
-- Knowbility
- Adobe entered a formal partnership with NV Access to improve NVDA's compatibility with PDF accessibility features and the PDF/UA standard (ISO 14289). Adobe issued a "Statement of Support for Open Source Assistive Technology." The partnership illustrates builder-side care -- a corporation investing in the assistive technology its users depend on rather than leaving compatibility gaps for blind users to navigate alone.
WebAIM Screen Reader User Survey #10 (January 2024)
-- WebAIM
- The definitive independent survey on screen reader usage found NVDA had become the most commonly used screen reader worldwide (65.6%), surpassing JAWS (60.5%). Respondents rated CAPTCHAs as the most problematic accessibility barrier -- a failure of builder-side design that no amount of screen reader sophistication can compensate for. 97.6% of NVDA users reported being somewhat or very satisfied with the tool.
- In 2008, the Mozilla Foundation awarded NV Access an $80,000 grant that allowed James Teh to work full-time on NVDA -- a builder-side investment in assistive technology infrastructure that transformed the project's trajectory.3
- In 2012, NV Access received the American Foundation for the Blind's Access Award, recognizing NVDA's impact on digital accessibility for blind users worldwide.6
- Microsoft published a feature profile of NVDA on its Microsoft Unlocked platform, reporting over 250,000 users in 175+ countries and acknowledging NVDA as critical infrastructure for blind digital participation.1
- Fernando, a blind job seeker in Brazil, wrote to NV Access: "Companies never hire us because they do not want to bear the cost of the screen reader. Making use of NVDA allows me to enter the labor market without requiring the company to bear the costs acquisition of a paid screen reader."7 The portability matters: unlike JAWS, which is tied to a licensed machine, NVDA can run from a USB drive on any Windows computer -- Teh described it as a tool that "can be copied to a USB stick, which can be used on any PC at school or university, with no installation required."3
- Bhavya, a blind high school student in India, wrote: "NVDA has transformed my life. Although I am still a high school student, I have been able to win Model United Nation conferences, achieve distinctions in mathematics and science related competitive examinations... largely due to the powers and abilities of NVDA, at no cost."7
What care sounds like (builder-side interventions)
Care at the design and development level involves building software that works with screen readers, not despite them:
- "Why do blind people have to pay so much when many of them are unemployed?" -- Michael Curran, explaining why he built NVDA as free software1
- "Accessibility and equitable access is a right and should be available to everyone." -- NV Access8
- "We test every release with NVDA and JAWS before shipping."
- "We're partnering with NV Access to ensure our PDFs are readable by screen readers." -- the premise of Adobe's 2012 partnership6
- "We wrote heading structures and ARIA labels so screen reader users can navigate by landmarks, not by guessing."
What neglect sounds like (builder-side interventions)
Neglect involves assuming that accessibility is someone else's problem -- or that screen readers will compensate for absent care:
- "Screen readers will figure it out, right?" (They won't. NVDA reads what builders write -- if the markup is empty, so is the experience.)
- "It looks fine, so we assumed it works." (Visual appearance tells you nothing about screen reader compatibility.)
- "We don't have blind users." (The WebAIM survey found 250,000+ NVDA users worldwide. You have blind users. You just can't see them leaving.)
- "JAWS handles our site fine." (JAWS uses heuristics to guess at bad markup. NVDA does not. Testing only with JAWS can mask failures that blind NVDA users hit every day.)5
- "We'll add ARIA labels in the next sprint." (Meanwhile, a blind person is tabbing through 47 unlabeled buttons.)
What compensation sounds like (navigator-side compensations)
Compensation describes the labor blind people undertake when builders ship inaccessible software and NVDA is the only way through:
- "I use a screen reader, but this site has unlabeled buttons everywhere. I have to guess what each one does."
- "I had to install a screen reader just to apply for this job. The application portal has no heading structure, so I Tab through every element on the page."
- "I carry NVDA on a flash drive because I never know if the computer I sit down at will have a screen reader installed."
- "I never know which website will be usable today. Some days I can buy groceries online; some days the checkout breaks and I have to call someone."
- "The screen reader works. The website doesn't. But everyone assumes the problem is my screen reader."
All observations occur within the context of the global assistive technology ecosystem, where NV Access's free screen reader has become the primary tool through which blind people in most of the world access Windows computers -- and the primary tool through which many developers discover whether their software is accessible at all.