The crawler
ReachcanonBot
ReachcanonBot is the crawler behind Reachcanon, an accessibility testing service. It visits public pages of a site when someone asks Reachcanon to test that site, and records how those pages behave for people who use a keyboard, a screen reader or a magnifier.
User agent
ReachcanonBot/0.1 (+https://reachcanon.com/bot; accessibility conformance scanning)
What it does
- Reads robots.txt first and obeys it for "ReachcanonBot" and "*". A robots.txt that cannot be read because the server failed (5xx) is treated as a refusal.
- Fetches pages with GET only, one request at a time per site, with a pause between requests, and stops at a small page limit.
- Opens each page in a real browser to run accessibility checks. It never submits forms and never sends a request that could change data: anything other than GET is blocked in the browser.
- Does not follow links to other sites, does not log in unless the site's owner has supplied access, and does not store page content beyond the short HTML snippet needed to find an element again.
Results belong to whoever ran the scan. Reachcanon publishes no list of scanned sites.
If your firewall blocks it
Bot protection (CloudFront, Cloudflare, Akamai and others) often answers 403 to crawlers it does not know. Reachcanon then reports that the site blocked the crawler, not that robots.txt refused it. If you want your own site tested, allow-list the user agent above.
If you do not want it
Add this to robots.txt and ReachcanonBot will not fetch your pages:
User-agent: ReachcanonBot Disallow: /
Questions or a complaint
Write to hello@reachcanon.com. Say which site and when, and we will look at the requests that reached it.