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 in the metrics-timeline Git repository and might be related to the displayed graph.
|Dates||Places/Protocols||Description and Links|
Decreased the rate limit on the meek-amazon bridge to 1.0 MB/s, from 3.0 MB/s.
|2016-10-19 to 2016-11-10||meek||
Large decrease in meek users, perhaps caused by problems in Orbot 15.0.2 BETA 1 that were fixed in Orbot 15.2.0 RC8.
ticket initial email followup email Orbot mail
geoip and geoip6 databases updated to "October 4 2016 Maxmind GeoLite2 Country" (
Rate limit on the meek-amazon bridge returns to 3.0 MB/s, having been set to about 1.0 MB/s for some time, cause uncertain.
Default obfs3 bridge LeifEricson upgrades and begins reporting statistics to the new bridge authority Bifroest. This is the last obfs3 bridge that hadn't upgraded.
Default obfs4 bridge LeifEricson upgrades and begins reporting statistics to the new bridge authority Bifroest. This is the last obfs4 bridge that hadn't upgraded.
|2016-09-23 to 2016-11-28||obfs3||
Outage of default obfs3 bridges "Unnamed" and "Unnamed" (fingerprint AF9F66B7B04F8FF6F32D455F05135250A16543C9). (Start date not known for sure, though it must have been after 2016-09-23; discussed in non-archived tor-team email.)
Default obfs3 bridges ndnop0 and ndnop2 upgrade and begin reporting statistics to the new bridge authority Bifroest.
post on bridges not reporting statistics
Default obfs3 bridges "Unnamed" and "Unnamed" (fingerprint AF9F66B7B04F8FF6F32D455F05135250A16543C9) upgrade and begin reporting statistics to the new bridge authority Bifroest.
Default obfs3 bridges ndnop3 and ndnop5 upgrade and begin reporting statistics to the new bridge authority Bifroest.
post on bridges not reporting statistics
macOS 10.12 (Sierra) is released, breaking some programs that are built with Go <1.7, including the meek-client that comes with Tor Browser. (See 2016-11-15 unbreaking event.)
geoip and geoip6 databases updated to "September 6 2016 Maxmind GeoLite2 Country" (
The former bridge authority Tonga shuts down. Bridges that have not updated to tor 0.2.8.7 or 0.2.9.2-alpha (which include all 5 default obfs3 bridges and 3/16 default obfs4 bridges) stop reporting statistics.
shutdown notice blog post loss of reporting bridges
CollecTor begins publishing bridge stats from the new bridge authority Bifroest.
tor 0.2.8.7 and 0.2.9.2-alpha are released, changing the bridge authority from Tonga to Bifroest.
|2016-08-24||China <OR> Unknown||
Large decrease in users in China.
Changed the meek-amazon CDN price class from "All" to "Use Only US, Canada and Europe."
geoip and geoip6 databases updated to "August 2 2016 Maxmind GeoLite2 Country" (
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.