We estimate the number of users by analyzing the requests induced by clients to relays and bridges.
This graph shows the estimated number of directly-connecting clients; that is, it excludes clients connecting via bridges. These estimates are derived from the number of directory requests counted on directory authorities and mirrors. Relays resolve client IP addresses to country codes, so that graphs are available for most countries. Furthermore, it is possible to display indications of censorship events as obtained from an anomaly-based censorship-detection system (for more details, see this technical report). For further details check the documentation on Reproducible Metrics.
The following events have been manually collected in the metrics-timeline Git repository and might be related to the displayed graph.
|Dates||Places/Protocols||Description and Links|
geoip and geoip6 databases updated to "IPFire Project Tue, 13 Apr 2021 05:11:07 GMT" (
Release of tor 0.3.5.14, 0.4.4.8, and 0.4.5.7. Changes the source of geolocation databases from Maxmind to IPFire.
blog post announcement ticket commit
geoip and geoip6 databases updated to "IPFire Project Fri, 12 Mar 2021 05:05:24 GMT" (
|2021-03-11||Belarus Relays Unknown||
Drop of relay users in Belarus. Bridge users are not affected.
relay graph bridge graph
Fire in the OVHcloud data centers located in Strasbourg takes about 48 relays offline in AS16276.
OVHcloud advisory Twitter thread
Decommissioned flash proxy badge server, flashproxy.bamsoftware.com.
Decommissioned flash proxy facilitator: server, flashproxy-reg-email poller, and flashproxy-reg-appspot app.
Outage of the Snowflake bridge.
|2021-02-13||Belarus Bridges meek obfs4||
Blocking of default obfs4 bridges and email-distributed bridges in Belarus. Relay users are not affected.
ticket BBS thread NTC thread relay graph bridge graph
Deployed version 0.5.3 of the Snowflake WebExtension, with improvements to NAT handling.
archive ticket comment
Release of Tor Browser 10.5a8, which fixes the bug preventing the use of default bridges.
blog post issue
Release of Tor Browser 10.5a7, which has a bug preventing the use of default bridges.
blog post issue issue
|2021-01-17 to 2021-01-21||snowflake Unknown||
Decrease in measured Snowflake users. May have been caused by a drop of NAT-unrestricted proxies.
mailing list thread comment
|2021-01-10 to 2021-02-03||onion||
Large amounts of traffic at directory authorities disrupts consensus, which causes v3 onion services to stop working because of a bug. Tor 0.3.5.13, 0.4.3.8, and 0.4.4.7 have a fix for the bug.
ticket blog post onion service traffic graph Tor blog post Tor Browser blog post status.torproject.org
Changed the DNS records for snowflake.freehaven.net and snowflake-broker.bamsoftware.com to be CNAME records for the corresponding torproject.net domains, rather than bamsoftware.com, in order to avoid malware warnings.
|2020-12-17 to 2020-12-20||snowflake||
DDoS attack on Greenhost, where the Snowflake broker and bridge and onionperf instances are hosted.
2020-12-17 status 2020-12-20 status anti-censorship-team thread
|2020-12-05 to 2020-12-09||meek moat||
An update to an Azure CDN edge server TLS certificate causes an outage of meek and Moat. It is fixed by the release of Tor Browser 10.0.6, which updates the built-in public key pinning of obfs4proxy.
ticket blog post meek graph BridgeDB graph certificate transparency
|2020-11-08 to 2020-11-09||snowflake||
Outage of the snowflake bridge
This material is supported in part by the National Science Foundation under Grant No. CNS-0959138. Any opinions, finding, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation. "Tor" and the "Onion Logo" are registered trademarks of The Tor Project, Inc.. Data on this site is freely available under a CC0 no copyright declaration: To the extent possible under law, the Tor Project has waived all copyright and related or neighboring rights in the data. Graphs are licensed under a Creative Commons Attribution 3.0 United States License.