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 see these questions and answers about user statistics.
The following events have been manually collected on this wiki page and might be related to the displayed graph.
|Dates||Places/Protocols||Description and Links|
|2017-12-01||<OR> ipv6 Relays||
Release of tor 0.2.8.17, 0.2.9.14, 0.3.0.13, 0.3.1.9, and 0.3.2.6-alpha, which add an IPv6 address for the bridge authority bastet.
ticket blog post
Outage of meek-amazon bridge.
Release of Tor Browser 7.5a8, containing tor 0.3.2.4-alpha, which adds a new directory authority bastet, and changes the IP address of the directory authority Longclaw.
Release of Tor Browser 7.0.10, containing tor 0.3.1.8, which adds a new directory authority bastet, and changes the IP address of the directory authority Longclaw.
|2017-11-11 to 2017-11-12||
Outage of the op-hk OnionPerf instance.
geoip and geoip6 databases updated to "November 6 2017 Maxmind GeoLite2 Country" (
Turned off the old meek-amazon CDN endpoint d2zfqthxsdq309.cloudfront.net.
mailing list post
Release of tor 0.2.5.15, 0.2.8.16, 0.2.9.13, 0.3.0.12, and 0.3.1.8, which add a new directory authority bastet, and change the IP address of the directory authority Longclaw.
blog post Bastet blog post bastet ticket Longclaw ticket
Activated client IP address statistics on the Snowflake server and standalone proxies.
geoip and geoip6 databases updated to "October 4 2017 Maxmind GeoLite2 Country" (
Permanent hardware failure of default FTE bridge 22.214.171.124:8080.
|2017-09-26 to 2017-10-22||Germany <OR> Relays Unknown||
Steady increase of relay users in Germany, from 180k to around 500k. It would increase further starting 2017-12-10.
de graph Reddit thread ticket
|2017-09-15 to 2017-09-16||Bridges||
The bridge authority was down due to an issue with its offline master key.
graph mailing list post
|2017-09-15 to 2017-10-12||
Outage of the op-hk OnionPerf instance. Reported timeouts on the tor network increased, download speed improved.
mailing list post torperf graph torperf-failures graph op-hk graph
|2017-09-14 to 2017-09-16||Bridges||
Outage of the bridge authority Bifroest.
geoip and geoip6 databases updated to "September 6 2017 Maxmind GeoLite2 Country" (
|2017-09-02 to 2017-09-21||obfs4 Unknown||
About a 35% increase in obfs4 users before returning to normal. Happened in many countries. Other transports do not have it.
|2017-09-01 to 2017-09-20||obfs4||
A flood of over 4,000 obfs4 bridges nicknamed "Machiavelli".
graph of number of bridges tor-relays post metrics-team thread tweet
|2017-08-14 to 2017-08-15||Bridges||
Outage of the bridge authority Bifroest.
mailing list post mailing list post graph
|2017-07-31 to 2017-08-28||Unknown||
Directory authorities using 2× bandwidth.
mailing list post for start mailing list post for end post suggesting link to nl, ro, lt, sc increases
|2017-07-29 to 2017-08-17||meek||
Outage of meek-amazon bridge, caused by an expired certificate.
Atlas expired certificate new certificate
|2017-04-14 to 2017-08-20||<OR>||
Directory authority maatuska's bwscanner stops operating, leading to a drop in traffic on some relays.
tor-consensus-health post about start tor-consensus-health post about end tor-dev thread analysis
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.