How our crawler works.
Passiro Crawler scans websites for accessibility issues. It's respectful, transparent, and easy to control.
Identification
How to identify our crawler
The Passiro Crawler identifies itself in every request with the following User-Agent string:
You can identify our crawler by looking for PassiroCrawler in the User-Agent header.
What it does
Built to scan, not to scrape.
Accessibility scanning
We load your pages in a headless browser and run axe-core, the industry-standard accessibility testing engine used by Google, Microsoft, and the W3C. We test against WCAG 2.1 AA standards.
Screenshots
We take screenshots of scanned pages to create visual reports that highlight exactly where accessibility issues occur. Screenshots are stored securely and only shown to the site owner or in public reviews.
Link discovery
We follow internal links to discover pages on your site. We only follow links within the same domain and respect a maximum page limit. We also check your sitemap.xml if available.
Crawl behavior
Respectful by design.
Rate limited
Maximum 2 requests per second. We never flood your server.
Template-aware crawling
Our crawler intelligently detects page templates. On e-commerce sites with thousands of product pages sharing the same layout, we automatically identify the template and move on to other unique page types. This means full coverage with minimal requests.
No data extraction
We don't scrape or store your content, prices, or user data. We take screenshots for visual reports and analyze the HTML structure for accessibility compliance — nothing else.
Timeout protection
Each page has a 10-second timeout, and total crawl time is capped at 5 minutes. We never hang on your server.
Same-domain only
We only follow links within the domain being scanned. We never visit external websites during a scan.
Smart scanning
Sees your site the way users do.
To produce accurate accessibility results and clean screenshots, our crawler automatically handles the popups and overlays that appear on modern websites.
Cookie consent banners — automatically accepted across all major consent platforms (Cookiebot, OneTrust, Usercentrics, Didomi, and more) in all 24 EU languages.
Popups and modals — newsletter signups, promotional overlays, and other interrupting elements are detected and dismissed.
Backdrop overlays — dimming layers and full-screen backdrops are removed so screenshots show the actual page content.
Shadow DOM — we traverse shadow roots to find and dismiss consent elements that are hidden inside web components.
Customization
Fine-tune the crawler for your site.
Our automatic detection handles most websites, but some sites have custom popups, unique consent flows, or elements that need special treatment. Site owners can configure custom crawler rules in the site settings dashboard to handle these edge cases.
Click selectors
Specify CSS selectors of buttons or elements the crawler should click before scanning — for example, to dismiss a custom popup our automatic detection doesn't recognize.
Hide selectors
Force-hide specific elements before taking screenshots. Useful for sticky banners, chat widgets, or overlays that shouldn't appear in your accessibility report.
Pre-set cookies
Set cookies before the crawler loads your pages — for example, a consent cookie to bypass the cookie banner entirely, or an A/B test cookie to scan a specific variant.
Ignored paths & page limits
Exclude specific URL paths from scanning and set a custom page limit. Useful if parts of your site are behind login or contain content you don't need scanned.
These settings are available in your site's Settings tab on the Passiro dashboard. Changes take effect on the next scan.
Your control
How to block our crawler
If you don't want the Passiro Crawler to visit your website, you can block it using your robots.txt file:
You can also block specific paths or sections of your site. We respect all standard robots.txt directives.
Alternatively, you can contact us and we'll add your domain to our exclusion list.
Questions about our crawler?
If you have questions, concerns, or need to report an issue with the Passiro Crawler, we're happy to help.
Contact us