How Extellio’s accessibility checks work
Extellio’s accessibility product helps you find accessibility issues on your website and organize the work needed to address them. It combines automated website checks, PDF checks and a checklist for manual assessment.
Before getting started, you may want to understand how the checks access your website, whether they affect your analytics, and what your IT team needs to know. In this article, we’ll go through how the product works and how it interacts with your website.
What does the product check?
Automated website checks help identify issues such as missing text alternatives, insufficient color contrast, and links or form fields without accessible names. PDF checks analyze discoverable documents for accessibility problems, while broken-link checks help you find links that no longer work.
The results show the issues found, where they occur and guidance to help you address them. You can explore findings by issue type or by page, which helps you identify problems that affect several parts of your website.
You can run checks on demand or schedule recurring checks, depending on your settings and subscription. Later scans help you follow up on changes and identify new issues.
How does it access your website?
The checks access your website from outside your organisation by requesting pages and documents over the internet.
Different checks work in different ways:
Browser-based checks load and examine rendered web pages, including content produced by JavaScript.
Link checks request pages and supporting resources to identify links that fail.
PDF checks download discoverable documents for analysis.
Screenshots, when enabled, provide visual evidence to help you locate and understand an issue.
Scanning public pages does not require access to your website’s source code, content management system, or database. You do not need to install an accessibility scanning script in your visitors’ browsers.
Who provides the service?
Extellio combines its own checks with technology supplied by Squidler AB. Squidler provides the browser-based website scanning used for part of the accessibility service. No personal data relating to Extellio’s customers is shared with Squidler. Extellio performs separate link and PDF checks and brings the findings together in the platform. Squidler company information.
Do we need to allow specific bots?
The scanning services need access to the pages, documents and supporting resources being checked. Several types of automated requests are involved, so allowing one bot name may not cover every part of the service. A page that opens normally for a person may still block an automated scanner.
Firewalls, bot protection, CAPTCHA and rate limits can prevent checks from reaching your content. If your website restricts automated access, contact Extellio before starting so that the appropriate access settings can be established with your IT team. Any exception should be limited to the access needed for scanning. You should not need to allow all bots or switch off your website’s security protection.
Pages behind a login or restricted network need a separately agreed approach. A page that could not be accessed has not been assessed; it should not be interpreted as having no accessibility issues.
Can we control which pages are checked?
The website configuration and scan settings determine the intended scope. However, excluding a result and preventing a scanner from accessing a URL are different things.
Extellio’s URL exclusions apply to its own crawler and to the results imported into the platform. These exclusions are not currently passed to Squidler’s full-site scanner. That scanner may therefore visit a URL even when its findings are excluded from Extellio.
You should also avoid relying on robots.txt to prevent scanning. Extellio’s current link and PDF crawler does not consult robots.txt when deciding which URLs to request.
If a page must never be accessed during scanning, agree the scope with Extellio and use appropriate website access restrictions.
Will scans be recorded as visits in Analytics?
They can be. Browser-based checks can run your website’s scripts, including analytics tags. Whether a visit is recorded depends on your tracking configuration, consent settings and traffic filters.
Rejecting cookies does not necessarily prevent a visit from being counted, particularly if your website uses cookieless tracking. You can read more about the distinction in our guide to implementing cookie consent with Cookiebot.
Direct link and PDF requests do not run the page’s JavaScript. However, requests can still appear in server logs, download statistics or systems that measure traffic through tracking images.
Can we exclude scan traffic from Extellio Analytics?
Yes. Extellio Analytics supports exclusions by IP address and user agent. You can find these settings under Data sources → Analytics → Settings → Tracking:
Excluded IPs excludes tracking requests from the specified IP addresses.
Excluded user agents excludes tracking requests matching the specified browser or automated-client identifiers.
To exclude scanning traffic reliably, the settings need to match the actual request sources used during your scans. Contact Extellio to confirm the appropriate configuration rather than assuming that automatic bot filtering removes every scan.
Our guide, How to exclude internal visits in analytics, explains IP exclusions and their limitations. They apply to future tracking and do not remove visits already collected. IP exclusions also cover heatmaps and session recordings; surveys require separate configuration.
Excluding traffic from Analytics does not prevent scanning or remove requests from your website’s server and security logs.
Will scanning affect website performance?
Scanning generates additional requests for pages, documents and supporting resources. The amount of traffic depends on the size of your website and which checks are running. Browser-based checks may load several resources for each page, much like a visitor’s browser does.
If your website has limited capacity, strict rate limits or particularly busy periods, discuss this with Extellio before running a broad scan. Recurring checks should use a frequency appropriate for your website.
Does scanning change anything on our website?
The product identifies and reports issues. It does not publish fixes or edit your website’s content. Your team makes the necessary changes in your website’s content or code, then uses subsequent checks to follow up.
Browser-based checking does load your website’s own code. That code can make requests, set cookies or trigger other behavior, just as it can during an ordinary visit.
If you want to assess journeys involving forms, purchases or account changes, agree the testing approach with Extellio first. These journeys need consideration beyond scanning publicly accessible information pages.
Accessibility scanning also serves a different purpose from a security assessment. Its findings should not be interpreted as confirmation that your website has no security vulnerabilities.
What information is collected?
Findings can include page addresses, issue descriptions, relevant HTML snippets and screenshots. PDF checks retrieve the document being assessed. This evidence helps your team understand and reproduce a problem. It also means that information visible on a scanned page or document may appear in the findings.
Before including sensitive content, confirm the intended access and data-handling arrangements with Extellio.
Does a scan with no issues mean our website is fully accessible?
Automated checks are one part of an accessibility assessment. Some questions require human judgement—for example, whether alternative text is useful, instructions make sense, or a complete journey works well with assistive technology. Extellio’s WCAG checklist helps you organize manual assessment alongside automated findings.
A scan with no reported issues does not, by itself, establish that your website meets every accessibility requirement. Consider which pages and states were reached, which checks were completed, and what still needs manual review.