Fastsoft / Guide
Practical guide
This browser contacts Fastsoft’s Cloudflare exit echo, an IP-literal echo at 1.1.1.1, IPv4/IPv6-only probes and popular sites. A site’s exit is measured only when its own Cloudflare trace can be read cross-origin.
How to use it
- Start the check and inspect four reference probes and each site result.
- If you know your direct and proxy exits, label their IPs under Route references, then set expected routes for sites to inspect measurable mismatches.
- Optionally add custom domains, apply the common China split-routing preset or copy Clash/Mihomo rules generated from your expectations.
Example
If Claude’s trace shows exit A while Fastsoft sees exit B, those requests used different exits. Verify which is direct and which is proxied before deciding whether Claude followed your intended rule.
What to know
Sites without a readable echo provide only an HTTPS response observation, not their observed exit. IPv4, IPv6 and IP-address probes contact different targets; differences alone do not prove IPv6 or DNS leaks or proxy safety. The Fastsoft echo does not store results; custom domains and route expectations stay in this browser.
Common question
Why does a site show “Reachability only” without an exit IP?
A browser cannot read the client IP seen by an arbitrary site. Without a readable cross-origin echo from that site, an HTTPS response is only a reachability clue.