The DNS resolver that lies to trackers
Every website you visit starts with a DNS query. Trackers abuse this to follow you everywhere.
DoH Split-Brain answers honestly for real websites and
sends trackers into a black hole.
The same DNS server gives different answers depending on who's asking for what.
163,000+ tracker, telemetry, malware, and ad domains return 0.0.0.0 (IPv4) or :: (IPv6). The request never reaches the tracker.
Block doubleclick.net and every subdomain is automatically blocked: stats.g.doubleclick.net, ad.doubleclick.net, etc.
We don't log your legitimate DNS queries. Only blocked tracker queries are logged for threat intelligence — and those contain the tracker's name, not yours.
Every blocked query generates a threat intel entry: timestamp, domain, query type. Aggregated data reveals which trackers are most aggressive across our user base.
Standard DNS-over-HTTPS. Works with every browser and OS that supports DoH. GET with base64url, POST with wire format. Proper application/dns-message responses.
Blocklist updates without downtime. Send SIGHUP and the new list is loaded in-memory instantly. No restart, no dropped queries.
Every blocked query is recorded. This data reveals tracking patterns across the internet.
Configure your browser or OS to use our DoH resolver. All DNS queries go through HTTPS — encrypted and filtered.
Settings → Privacy & Security → DNS over HTTPS → Custom
URL: https://synthetic-context.net/v1/doh/dns-querySettings → Privacy and Security → Use secure DNS → Custom
URL: https://synthetic-context.net/v1/doh/dns-query# Install a DNS profile pointing to:
https://synthetic-context.net/v1/doh/dns-query# /etc/systemd/resolved.conf
[Resolve]
DNS=synthetic-context.net
DNSOverTLS=yes# Resolve example.com (A record)
curl -s "https://synthetic-context.net/v1/doh/dns-query?dns=AAABAAABAAAAAAAAB2V4YW1wbGUDY29tAAABAAE"# Send DNS wire-format query
curl -s -X POST "https://synthetic-context.net/v1/doh/dns-query" \
-H "Content-Type: application/dns-message" \
--data-binary @query.bincurl -s "https://synthetic-context.net/v1/doh/health"
# {"status":"ok","blocklist_size":163181,"stats":{"total":...,"blocked":...}}| DoH Split-Brain | Cloudflare 1.1.1.1 | AdGuard DNS | NextDNS | |
|---|---|---|---|---|
| Tracker blocking | 163K domains | No | Yes | Yes |
| Threat intel feed | Yes | No | No | No |
| RFC 8484 | Full | Full | Full | Full |
| Query logging | Blocked only | Optional | Optional | Yes (dashboard) |
| Open source | Python | No | No | No |
| Self-hostable | Yes | No | No | No |
| Account required | No | No | No | Yes |
| Price | Free | Free | Free/Paid | Free/Paid |
Our blocklist is compiled from Steven Black's unified hosts, covering:
Google Analytics, DoubleClick, Facebook Pixel, Twitter tracking, LinkedIn Insight, and thousands more ad networks.
Microsoft telemetry, Mozilla telemetry, Adobe activation, app analytics SDKs, crash reporters that phone home.
Known malicious domains, phishing sites, cryptojacking scripts, and command-and-control servers.