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|
|2018-08-04 to 2018-08-05||
Collector was missing consensuses. They were recovered via recent relay consensus diffs.
metrics-team thread tor-relays thread
The estimated number of bridge users becomes available again, following the introduction of the new bridge authority Serge on 2018-07-13. The stats took about a week to reappear because of the discontinuity in bridge reporting affecting the estimated fraction of reporting bridges.
mailing list post graph
Made the Snowflake bridge report to the new Serge bridge authority.
|2018-07-14 to 2018-07-25||Iraq||
Protests, Internet shutdowns, and social media blocks in Iraq.
relay graph NetBlocks post NRT article about end Psiphon users
Release of Tor 0.2.9.16, 0.3.2.11, 0.3.3.9, and 0.3.4.5-rc. Switches bridge authority from Bifroest to Serge. The number of bridges begins counting up from zero as bridges are upgraded. The estimated number of bridge users remained unavailable until 2018-07-21 because of the discontinuity.
announcement ticket blog post number of bridges graph
The replacement bridge authority Serge begins publishing bridge descriptors.
ticket ticket number of bridges graph
geoip and geoip6 databases updated to "July 3 2018 Maxmind GeoLite2 Country" (
The bridge authority Bifroest stops publishing bridge descriptors. Bridge stats are unavailable until 2018-07-13 and the introduction of a new bridge authority.
ticket ticket mailing list post number of bridges graph
|2018-07-04 to 2018-07-06||snowflake||
Outage of the Snowflake bridge, caused by a full disk.
Release of Tor Browser 8.0a9 with non-working meek.
blog post ticket
|2018-06-24 to 2018-07-06||snowflake||
Metrics for Snowflake are missing, for unknown reasons. The gap is nearly contemporaneous with the gap the measurements for all transports/bridges caused by Bifroest–Serge bridge authority switchover, but starts about 2 weeks earlier in Snowflake's case.
geoip and geoip6 databases updated to "June 7 2018 Maxmind GeoLite2 Country" (
Release of Tor Browser 8.0a8, removes meek-amazon option.
Release of Tor Browser 7.5.5, removes meek-amazon option.
|2018-05-22 to 2018-06-08||Iraq obfs4 Unknown||
Increase in obfs4 users in Iraq, followed by a slow decrease. No matching change in relay users or other transports.
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.