How to Help
How it Works
How to Use It
Some Technical Information
As of 2017, the flash proxy project is deprecated.
It was deployed in Tor Browser between 2013 and 2016,
but has since been superseded by newer and more effective
If you want to help support a newer circumvention system
designed along the same principles as flash proxy, please see
Flash proxies are a way of providing access to a censorship
circumvention system such as Tor.
A flash proxy is a miniature proxy that runs in a web browser. It checks
for clients that need access, then conveys data between them and a Tor
Tor has bridge
relays, but in some cases even these can be blocked despite the fact
that their addresses are handed out only a few at a time. The purpose of
this project is to create many, generally ephemeral bridge IP addresses,
with the goal of outpacing a censor’s ability to block them. Rather than
increasing the number of bridges at static addresses, we aim to make
existing bridges reachable by a larger and changing pool of addresses.
“Flash proxy” is a name that should make you think “quick” and
“short-lived. ” Our implementation uses standard web technologies:
(In the long-ago past we used Adobe Flash, but do not any longer. )
while you are viewing this page your browser is a potential proxy
available to help censored Internet users.
Copy and paste this HTML into your web site or blog. An example is at
the bottom of this page.
There is an options page (the same page you
get by clicking on the badge) with which users can choose whether they
want to be a proxy. By default, if a user has not made a choice, they
will be a proxy. If you want only people who have explicitly clicked
“yes” to be a proxy, add the cookierequired parameter. If a
user has selected “no, ” they will never be a proxy, regardless of the
presence of cookierequired.
Cupcake is an
always-on flash proxy plugin for Chrome. Click
here to install from the Chrome web store.
Flashproxy Badge is an always-on flash proxy plugin for Firefox.
here to install from Mozilla Add-Ons.
your Wikipedia skin to include a flash proxy badge.
This paper contains a fuller description of the system and the results
of performance experiments.
Evading Censorship with Browser-Based Proxies (PDF)
In the Proceedings of the 12th Privacy Enhancing Technologies Symposium (PETS 2012), LNCS 7384, pp. 239–258, 2012.
An overview of the flash proxy system and its state of development as of
How It Works
In addition to the Tor client and relay, we provide three new pieces.
The Tor client contacts the facilitator to advertise
that it needs a connection. The facilitator is responsible for keeping
tack of clients and proxies, and assigning one to another. The
flash proxy polls the facilitator for client
registrations, then begins a connection to the client when it gets one.
The transport plugins on the client and relay broker
the connection between WebSockets and plain TCP.
A sample session may go like this:
The client starts Tor and the client transport plugin program
(flashproxy-client), and sends a registration
to the facilitator using a secure rendezvous. The client transport plugin
begins listening for a remote connection.
A flash proxy comes online and polls the facilitator.
The facilitator returns a client registration, informing the flash
proxy where to connect.
The proxy makes an outgoing connection to the client, which is
received by the client’s transport plugin.
The proxy makes an outgoing connection to the transport plugin on
the Tor relay. The proxy begins sending and receiving data between the
client and relay.
The whole reason this is necessary is because the client cannot
communicate directly with the relay. (Perhaps the censor has enumerated
all the relays and blocked them by IP address. ) In the above diagram,
there are two arrows that cross the censor boundary; here is why we
think they are justified. The initial connection from the client to the
facilitator (the client registration) is a very low-bandwidth,
write-only communication that ideally may happen only once during a
session. A careful, slow, specialized rendezvous protocol can provide
this initial communication. The connection from the flash proxy to the
client is from an IP address the censor has never seen before. If it is
blocked within a few minutes, that’s fine; it wasn’t expected to run
forever anyway, and there are other proxies lined up and waiting to
Doesn’t the censor win just by blocking the facilitator? Doesn’t this
shift the problem from bridge-blocking to facilitator-blocking? The
short answer to these questions is no. We assume that
the censor has blocked the facilitator. For more details, see the
From the user’s perspective, only a few things change compared to using
normal Tor. The user must run the client transport plugin program and
use a slightly modified Tor configuration file. Complete details are in
Flash proxy is built into Tor Browser.
Follow this link to download Tor Browser.
Tor Browser download page
Next, read the
proxy howto to learn how to configure port forwarding. See the
manual configuration in the rest of this section if the browser bundle
Limitations on outgoing connections
It is a restriction of WebSockets
that they cannot receive TCP connections, only open them.
That is the reason for the client transport plugin: it allows Tor to
receive connections instead of making them.
The badge changes color depending on its state.
Dark blue means the proxy is running but no client is being served.
Light blue means a client is currently being served.
Gray means that the badge has disabled itself. This can be because
it has detected it is running on a mobile device, or the browser doesn’t
support WebSocket (this happens on Internet Explorer 9).
Black means that there was an internal error and the proxy is no
All the programs making up the flash proxy system are free software and
their source code is visible. To get a copy of everything, run this
Or browse the code through
Flash proxies began as a project in Stanford’s
CS294s class in spring 2011.
David Fifield, Nate Hardison, and Jonathan Ellithorpe were members of
the project team. They and Emily Stark, Roger Dingledine, Phil Porras,
and Dan Boneh wrote a research paper on the
subject. Development continues as part of
the Tor Project.
Estimated average number of concurrent users. See the
site for more control over the graph and historical measurements.
David Fifield <>
Research paper (PDF)
Bug reports and open tasks
(including closed tickets)
Lots of Flash Websites are Still Out There – 3 Years On
How to Enable Flash in Your Web Browser – UMass Amherst
Adobe Flash is a software platform for the browser that enables the display multimedia such as animations and other graphical content that is being phased out of active development. Flash is still used in some platforms, such as OWL, and requires being enabled in most browsers in order to properly show content.
The steps below will show you how to enable Flash for a particular website in each of the major browsers in order to view content.
How to Enable Flash in Microsoft Edge:
Navigate to the website you want to enable Flash on.
Select the information icon next to the website’s address in the address bar to bring up the drop-down as shown and click on Allow Adobe Flash.
Under Website Permissions, ensure the slider for Adobe Flash is moved to the On position as shown.
How to Enable Flash in Microsoft Internet Explorer:
Open Internet Explorer.
Select the Settings cog at the top right-hand side of the window and select Manage add-ons from the menu that appears.
Make sure Show: on the lower-left hand side has All add-ons selected and highlight Shockwave Flash Player in the list. Then click Enabled to enable it.
Select Close in the bottom right to return to the webpage, and reload it if necessary. Flash should now be working!
How to Enable Flash in Mozilla Firefox:
Open Mozilla Firefox.
Navigate to a page that uses Adobe Flash and a new add-on iconwill appear next to it in the address bar. Click that icon to open the menu. Select the checkbox next to Remember this decision if you want to continue to allow Flash to run on this site in the future. Then click Allow.
How to Enable Flash in Google Chrome:
Open the website you want to enable Flash on.
Click the information icon or the lock icon in the website addressbar at the top left. From the dropdown that appears, select Site Settings.
From the menu that appears, next to Flash, select Allow.
Close the Settings window. you may need to reload the page with Flash content that you were trying to access.
How to Enable Flash in Apple Safari:
Open the website you want to enable flash on.
From the menu bar, choose Safari and then Preferences.
Select the Websites tab and then underneath Plug-ins, ensure that the box next to Adobe Flash Player is selected.
Once selected you will see a list of websites. From the website you want to enable Flash for in the list and change the drop-down to On.
Close the window and return to the page you were previously on. Reload the webpage if necessary.
Frequently Asked Questions about proxy sites with adobe flash player
What sites still use Flash Player?
Even more surprising was their list of popular websites that are still using Flash:Google.com.Sohu.com.Mail.ru.Babytree.com.Ok.ru.Cnn.com.Jrj.com.cn.Globo.com.More items…•Jul 25, 2020
How do I access websites that require Adobe Flash Player?
How to Enable Flash in Google Chrome:Open the website you want to enable Flash on.Click the information icon or the lock icon. in the website addressbar at the top left. … From the menu that appears, next to Flash, select Allow.Close the Settings window.
Can you still play Adobe Flash after 2020?
Yes—there are still ways to play Adobe Flash content using a Flash player in 2020, but support for it is officially dead. It’s time to move on from Flash and embrace HTML5, but before you do, use the built-in Flash player in Chrome to enjoy your older content while you still have the chance.Mar 10, 2020