What is Deque is really two questions. There is Deque Systems, a private company founded in 1999 in Herndon, Virginia, led by founder and chief executive Preety Kumar. And there is axe, the open-source engine it released in 2015, which has passed three billion downloads and is embedded in Lighthouse, Playwright and most third-party accessibility tooling on the market.
If you have ever run an accessibility check in Chrome DevTools, you have used Deque’s code. So what is Deque selling, if the engine is free? Tooling, training and a workflow for engineers.
That gives Deque a position nobody else in this category has. Where Siteimprove, Silktide and Acquia Web Governance sell dashboards to web teams, Deque sells tooling to engineers, and gives the engine away.
It also carries an unresolved documentation problem that a developer flagged in Deque’s own issue tracker two and a half years ago and nobody at the company has answered.
This piece covers the company, the product lineup, what the free tier actually gets you, the coverage numbers and why two of them are both true, the CMS gap, who it is for, and where the "just use axe" advice stops working.
The short version: the free tier is the best in this category by a wide margin, a solo developer can run a real accessibility practice for under a hundred dollars a year, and the paid products assume you have a test pipeline. If your client’s accessibility owner is an editor rather than an engineer, Deque is the wrong tool, and it has no CMS plugin to bridge that gap.
What is Deque actually selling
In Deque’s own words:
- axe-core is "the world’s most trusted open source accessibility engine"
- axe DevTools is "automated accessibility testing for web and mobile"
- axe DevTools Linter will "’spellcheck’ static code for accessibility"
- axe Monitor does "site-wide scanning, reporting, and business intelligence"
- axe Auditor is "systematic manual accessibility testing"
- axe MCP Server offers "one-click accessibility fixes right in your IDE"
- axe Assistant gives "guidance, code fixes, and verified citations via our AI chatbot"
One licensing detail that no comparison mentions and that may matter more than any feature. axe-core is licensed MPL-2.0, not MIT. That is a file-level copyleft license. Siteimprove’s Alfa engine is MIT. If you are an agency embedding an accessibility engine into a distributed product or a white-labeled client deliverable, that difference is a real legal review item, and it is the kind of thing that surfaces late and expensively.
The linter covers React, React Native, Vue, Angular, HTML and Markdown, runs in VS Code, IntelliJ and WebStorm, and integrates with GitHub, Jenkins, SonarQube, CircleCI, Travis, GitLab, Azure DevOps and Bamboo, plus a REST API and a CLI.
axe Developer Hub plugs into Cypress, Playwright, Puppeteer, Selenium and WebdriverIO, deduplicates findings, tracks trends and can block pull requests. That last capability is something no governance platform in this category offers at all.
The mobile product covers native iOS, native Android, React Native, Flutter and .NET MAUI, with an interactive mode that needs no source code access.
The AI layer moved fast in 2025 and 2026. Deque announced Advanced Rules, AI-assisted guided tests, axe Assistant and MCP support in February 2025. In February 2026 the axe MCP Server was folded into the axe DevTools for Web bundle at no additional cost, working with GitHub Copilot, Cursor, Claude Code and VS Code. In August 2026 it added automated guided tests, authenticated testing via cookie injection, local install through npx without Docker, component-scoped scanning, batch remediation of up to 25 issues per request, and on-premises deployment with customer-managed models.
What the free tier actually gets you
This is the strongest small-shop story of any vendor in the category, and it deserves to be spelled out.
- axe-core: free, MPL-2.0
- axe DevTools browser extension, free tier: "conduct basic, automated testing on a page-by-page basis"
- axe Accessibility Linter for VS Code: free
- Deque University, IAAP CPACC course: $60 a year
- Deque University, Web Accessibility course: $250 a year
- Deque University, full access: $450 a year
- Deque University scholarship: free access for people with a qualifying disability
A two-person agency can have a genuine accessibility practice, including a recognized certification track, for sixty dollars a year. Nothing else in this category comes close.
On paid pricing, Deque has gone quieter, not louder. The current pricing page describes tiers in words with no dollar figures and a "Schedule a Demo" button. At launch in March 2021 Deque publicly priced axe DevTools Pro at $40 a month or $409 a year. That figure is now five years stale and still circulates on review sites. Do not quote it.
Third-party transaction data reports an average Deque contract value of $29,200 a year across 37 purchases, with a range of $6,350 to $47,300. Treat the average and range as transaction-derived and the tier bands those aggregators publish as modeled estimates.
The coverage numbers, and why two of them are both true
Here is the thing that will confuse anyone comparing vendors, and it is worth getting exactly right.
The axe-core README says this, and the emphasis is Deque’s own:
"With axe-core, you can find on average 57% of WCAG issues automatically."
The axe DevTools marketing page says this:
"Catch and fix up to 80% of accessibility issues before they reach production."
A developer opened issue #4415 in Deque’s own axe-core repository in April 2024 asking which number is correct, because he needed one for a leadership presentation. As of September 2026 that issue is still open, has no comments, and nobody from Deque has replied in it.
The reconciliation exists, and it is coherent. It is published in two Deque reports, neither linked from the README or from the 80 percent line. Deque’s own blog states it plainly: automated testing alone identifies 57.38 percent of accessibility issues, and combined with Intelligent Guided Tests that rises to 80.39 percent.
So 57 percent is axe-core’s automated rules on their own. 80 percent is axe-core plus a human answering questions in a wizard inside the paid Pro extension. The guided tests add roughly 23 points, and the remaining fifth needs expert manual testing.
Three things that reconciliation does not dissolve, and they belong in any comparison you do:
The denominator is different from everyone else’s. Deque measures coverage as the volume of individual issues found, not as the percentage of WCAG success criteria that automation can test. It says so openly, and positions its reports explicitly against what it calls the widely held belief that automated testing covers 20 to 30 percent. Both framings can be true of the same tool. But Siteimprove’s 30 to 40 percent and Silktide’s 40.8 percent are success-criteria figures. Putting 40 percent and 80 percent in the same table without a footnote produces a misleading table.
The 80 percent was never an automation-only number. The original 2021 launch release described a range of 76 to 84 percent through "a combination of human and machine learning technology." That phrase is absent from today’s headline.
The AI features are now blurring the line Deque itself drew. If AI-assisted guided tests answer the wizard questions without a developer, the 57 and 80 figures start describing the same configuration. The README has not been updated and the marketing line has not been qualified.
None of this is fabrication. It is a documentation hygiene failure at a company whose core asset is developer trust, and a developer asked them to fix it in their own tracker two and a half years ago.
Deque and overlays, because the halo is narrower than you think
The community narrative is that Deque is the anti-overlay vendor. That is mostly true today and was not true historically, and an honest comparison should say so.
In April 2020 Deque published a post distinguishing two kinds of overlay rather than condemning the category, criticizing toolbar overlays as "cheap assistive technologies that do little to improve the real accessibility of Web properties" while endorsing the other kind:
"Custom JavaScript accessibility overlays are a great short-term solution that helps to give your organization time before a sustainable accessibility program."
The post positioned Deque’s own product, Amaze, as that legitimate interim tool. Karl Groves, who maintains the Overlay Fact Sheet, criticized Amaze by name, arguing that clients end up paying for "both rounds of repair: The custom overlay plus the final repairs."
Amaze no longer appears anywhere in the axe lineup. We found no formal discontinuation announcement, so the accurate phrasing is that it is no longer marketed rather than that it was discontinued.
The point is not that Deque is compromised. It is that "overlay company versus clean company" is not a line this industry actually divides along, and anyone using that line to sell you something is simplifying.
The CMS gap
Deque ships no official WordPress plugin and no official Drupal module. We searched specifically. What exists is a community Drupal module that uses axe-core but is not a Deque product.
Deque’s route into a content shop is the browser extension and the test pipeline, not something an editor installs. For an agency whose clients are WordPress and Drupal sites maintained by communications staff, that is a real gap, and it is the gap every governance platform in this category exists to fill.
Where Deque is architecturally ahead is everything that touches a developer’s environment. The extension runs in your browser, so localhost and VPN-only staging work by construction. axe-core in CI runs inside your pipeline against ephemeral preview environments, so no vendor crawler needs network access to anything. axe Monitor supports basic, NTLM, Kerberos and client certificate authentication with uploadable pre-auth scripts. The MCP server added cookie-injection authentication and on-premises models in August 2026.
Siteimprove and Acquia cannot see a private network at all. Silktide will reach one for a fee. Deque never needed to, because its tools run inside your environment rather than outside it.
Who it is for
The short answer to what is Deque for is engineers. Genuinely for: organizations with engineers who run automated tests. The value concentrates in CI/CD, the IDE and the audit workflow. A team with no test pipeline is buying maybe a third of what it pays for.
The smallest customer that gets real value is one person. Free engine, free extension, free linter, and a sixty dollar certification course. That floor is unmatched.
Where it stops making sense: a non-technical publisher on a hosted CMS with no build step and no developer. There is no plugin, no dashboard for a marketing manager, and the commercial products assume a pipeline. The observed commercial entry point is around $6,350 a year.
Forrester named Deque a Leader in its Q4 2025 Digital Accessibility Platforms Wave with top scores on 21 criteria, more than any other vendor evaluated, describing it as "consistently first to market with innovative features." Note that Siteimprove and Level Access were also named Leaders in that Wave, so the label sorts the top tier from the rest rather than sorting these vendors from each other.
Where "just use axe" breaks down
The advice is mostly right and it fails in five specific ways worth knowing.
Just using axe gets you 57 percent, not 80. The 80 needs paid Pro and a human answering prompts. Conflating them is the most common buyer error in this category, and Deque’s own marketing makes it easy to make.
The license is MPL-2.0, not MIT. For an agency embedding an engine into something it distributes, that is a legal review, and Siteimprove’s Alfa is the permissive option.
It is not a CMS tool. No WordPress plugin, no Drupal module.
Deque sold an overlay, and defended the category in print in 2020.
The AI layer is early. The accessibility specialist Craig Abbott tested axe Assistant in May 2025 and found it missed that an <h1> outside <main> could cause problems, failed to structure headings properly in its suggested fix, and did not notice text written entirely in uppercase. His summary was that it "performed exactly as I’d expect a Large Language Model to perform," producing generalized information that fell short when asked to be specific. He did allow that the content design suggestions were good.
Frequently Asked Questions
What is Deque?
A private accessibility company founded in 1999 in Herndon, Virginia, best known for axe, the open-source accessibility engine embedded in Lighthouse, Playwright and most third-party accessibility tools.
Is axe free?
axe-core is free and open source under MPL-2.0. The axe DevTools browser extension has a free tier, and the VS Code accessibility linter is free. The Pro and enterprise products are paid and Deque no longer publishes their prices.
What license is axe-core under?
Mozilla Public License 2.0, which is file-level copyleft. This differs from Siteimprove’s Alfa engine, which is MIT, and the difference matters if you embed an engine in something you distribute.
Does axe find 57% or 80% of accessibility issues?
Both figures are Deque’s and they describe different configurations. 57 percent is axe-core’s automated rules alone. 80 percent is those rules plus a human answering questions in Intelligent Guided Tests inside the paid extension.
Why do Deque’s own docs and marketing disagree?
They do not disagree so much as measure different things without saying so on the same page. A developer opened an issue in Deque’s repository in April 2024 asking for a reconciliation. As of September 2026 it is still open with no reply.
Can I compare Deque’s 80% with Siteimprove’s 30 to 40 percent?
Not directly. Deque measures the share of individual issues found. Siteimprove and Silktide measure the share of WCAG success criteria that automation can test. They are different denominators.
Does Deque have a WordPress or Drupal plugin?
No. There is a community Drupal module that uses axe-core, but it is not a Deque product. Deque’s route into a CMS shop is the browser extension and the test pipeline.
Can it test staging or localhost?
Yes, better than any governance platform. The extension runs in your browser and the CI integrations run inside your pipeline, so nothing external needs network access to your private environments.
What does the paid product cost?
Deque does not publish it. Third-party transaction data reports an average contract value of $29,200 a year with a range of $6,350 to $47,300. A 2021 published price of $409 a year for Pro still circulates and is five years out of date.
Is Deque an overlay vendor?
Not today. It did ship a custom JavaScript overlay called Amaze and published a defense of custom overlays in 2020. Amaze is no longer marketed, though we found no formal discontinuation notice.
What is the cheapest real accessibility practice I can build?
The free engine, the free extension, the free VS Code linter and a sixty dollar a year IAAP CPACC course through Deque University. For a small agency that is a genuine practice at close to zero cost.
Should I buy Deque or a governance platform?
Ask who owns accessibility at the client. Deque assumes a developer. Siteimprove, Silktide and Acquia assume a web or communications team. Buy the one whose assumed owner actually exists in the organization.
