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Pry-Fi released (root required)

You are being watched...

Retailers, crooks, the government, and others shady individuals are tracking your movements. Even when your Wi-Fi is turned off, your phone may be broadcasting information to whomever is in range which can be used both to track repeated visits to as well as your exact movements in an area under surveillance.

It's not a big step to couple this to personal information - a retailer for example, could track your trip to the register and correlate with your payment information. Now the tracking hardware and software vendors, the store (or chain) owner, their business partners, they can now all track where you are every time you come into range of one of their systems, and fully profile who you are, what you do, your financials, and your daily patterns! 

That is just one example, but there are many uses for tracking you. Make no mistake, this is happening in the real world today.


One solution is shutting off Wi-Fi completely (including the background network scanning, a setting most people don't know about), but you would lose benefits like automatically connecting to known Wi-Fi networks and improved location awareness for your apps. It also does nothing to help the situation for others.

Pry-Fi will prevent your device from announcing all the networks it knows to the outside world, but it will still allow background scanning and automatically connecting to Wi-Fi networks. While you are not connected to a Wi-Fi network, the MAC address will constantly be pseudo-randomized, following a pattern that still makes the trackers think you are a real person, but they will not encounter your MAC address again. This will slowly poison their tracking database with useless information.

When you do connect to a Wi-Fi network, unless you specify otherwise, your MAC address will also be randomized - the same MAC address will not be used the next time you connect to this or any other network.


Though of course the companies involved with these trackers claim they wouldn't use the data maliciously, the possibility is there, and we all know that if something can be abused, ultimately it will be. There do not appear to be any laws against these practices yet, nor is it likely Wi-Fi will be redesigned any time soon to get rid of the information leaks.

But we can make an effort to reduce the usefulness of the tracking data for the exploiters. Pry-Fi comes with a War mode, which when enabled tries to make your Android device appear like dozens of people. Just wandering around an area under Wi-Fi location surveillance for a few minutes can ruin the tracking data for the period of your stay.


This is proof-of-concept code, and how for it will go in the future depends on interest and how well it works. It has been tested on several devices and seems to work, but it is very young still. The magic the app does to achieve its purpose is ever subject to changing Android security policies and OEM customizations, so even though it works now, there really is no saying if it will still be possible in future firmwares.

Of course you should also keep in mind that tracking can be done in many ways, and these W-Fi signals are far from the only method in use.


Further details, device compatibility information, FAQ, discussion, etc is all available on here:

The description for this app is currently being written. Check back in a fe...
Pascal Fiedler (Junpei Shibayama)'s profile photoxXNachoGamesXx // NG89's profile photoTheekshana Ambepitiya's profile photoJohnny Jones's profile photo
Awesome - been waiting for an app like this for a long time. Amazing stuff as usual, CF. :)

Edit: Unable to upgrade to Pro - "The item you requested is not available for purchase." :(
It says the pro version is not available for purchase
I'll give it a go on my N4.
thats an useful app , well done
+Shiv Manas Dass +Jeff Bollinger Hah, there's always something wrong with IAPs the first release. I don't think I've ever released something where that worked correctly immediately. IAP testing is a bit broken. Wait for next update :)
force close on n4, after that wifi not working anymore! log sended! 
Installed this first thing even though I am not too worried (yet) about the current state of affairs. +Chainfire you are awesome. 
Kay Hayen
Yes, lets all make sure only Google and NSA know where we are. That will increase their value and decrease the value of everybody else.

Lets make the monopoly that creates the rules ever more powerful than it already is, so it can take our freedom entirely away.

Anything that doesn't limit them, but others, is their progress towards world domination.
So, you haven't tested the app on N4, forgot to list it, or isn't it compatible?
I can't connect to my home WiFi while pryfi is on. Always got 'authentication problem' even if mark my WiFi to use original Mac. I'm using a Oppo N1 with Omni ROM.
It's currently quite unstable (crashes and forgot my home wifi, HTC One GSM with Omni nightly.) However, after a little fiddling it seems to run now. Keep up the good work. Once the glitches are ironed out it'll be great!
+Malthe Høj-Sunesen I don't own an N4. Somebody else posted it works on his N4, though.

+Juan José It may be your chip does not allow changing MAC address (this is actually documented in the XDA thread, you know), as is the case with the Xperia Z. If that is the case, there is nothing that can be done, really.
Will this also interfere with googles location history / android device manager/ location reporting services as they use wifi among other ways to determine your location? +Chainfire
Thanks +Chainfire. I've readed the xda post after post the comment here. There something I can do to check if this is the problem?
+Juan José Turn Wi-Fi off, go into Pry-Fi -> Manage Networks, mark your network to "use original MAC", disable Pry-Fi, enable Pry-Fi, enable Wi-Fi, wait a minute, see if it works now. If so, your device cannot change MAC - it reports that it does, but it actually doesn't, and all blows up :)
Errors  MIP : 67 & EHRPD : 7
Turning off enables connection. Ver 1.01
Sprint Note 3 stock rooted twrp recovery.
This is a pretty cool app. thx.
Latest nightly CM11 N4 not working, tried your instructions above but no luck, won't connect to wifi, seems as if it creates a new wifi list as it asks for the password to a wifi that's already saved, turn off prfyfi and it instantly reconnects to the net no problem (ssid set to use original mac) 
И что это???? 
Another step in the right direction against corporate Amerika.

Thanks for making this and keeping up the good fight
+Chainfire does the war mode use any means of waking my phone while on? I'm concerned about the battery drain.
Not that I experience any, just wanted to know if it's not a trouble.
Just by the way thank you for this app. I'm about to go shopping to a nearest center. ;-)

PS. So far everything's fine on my N4 running Omni and AK kernel with prima drivers. 
great +Chainfire 
Thanks also for compatibility with my two devices [N700 and N7100] 
Great article and writing text. 
And even if in the near future it may not work on other future firmwares, satisfaction I've had the time for the hard work we offer solutions to the users. 

Downloading and testing :) 
Nice weekend to you 
+Marcin Pająk In war mode it does keep your CPU and Wi-Fi awake, so yes, this will cost battery power (as stated in the description). That's also why it's on a timer...
+Chainfire thank you for clearing it up for me. After all war needs some sacrifices. ;-)
So... how does it work?
The only 99.9% sure way of turning WiFi off is thru removing the adapter's kernel module from the kernel but most firmwares get the wifi module built-in the kernel image and thus making them impossible to rmmod.
Triggering the rfkill switch could just cause a false positive. Calling to android functions could just return ok without an actual switch-off.
And the wifi adapter could have a two ways of comunicating with the rest of the device. An userland bus for regular wifiing and a hidden bus that does not need the oem firmware and kernel module to operate.
+Pașca Alexandru If you read the description, you'd see this app is not about turning Wi-Fi off, it's about changing what it sends out. And during testing I monitor that with a dedicated sniffer ...
+Chainfire still 1.00 here in EU. Just checked it. 
Looks like a great concept. Not compatible with Xperia S, but I've added it to my wish list for the next phone.
+Chainfire thank you for this app! I'd like to see it on f-droid's repo. Is it possible?
No me queda muy claro que es lo que hace exactamente. Intalada en N5 y fallo con supersu. Tengo superusuario.
It works! I can't enable WiFi anymore so I guess I am safe now ?
After enabling it keeps crashing on my Nexus 4. Nexus 7 is fine though.
Ah ok on N4 I got 1.01, on N7 its 1.02.
When its enabled I cannot connect to my home network anymore. Even with other devices where Pry-Fi is not installed!
I did enable keeping original MAC for this network. So Pry-Fi locks me out from WiFi, that's a critical bug.
Btw, hidden SSID in this network. AP is an AVM 7390.
Crashes Wifi on Note 3 4.4.2 had to uninstall and reflash custom rom to get Wifi again 
+Sergey Briskin unlikely

+Zoltan Fürst As stated in the FAQ, hidden SSIDs are not supported.

+Seoras Mackay +Muamer Seferovic Is that a custom ROM, or rooted Samsung 4.4.2 ? I had serious trouble on S4 and Note3 until I flashed the latest TrustZone partition. Else I would see a lot of TZ related crashes in logcat.
for me its indies OmegaROM with android 4.3 on s4 ...
Thanks for this, +Chainfire. Will definitely give it a go. Any chance of adding a home screen widget or a toggle to quick settings? 
reflashing the ROM didn't work ... so I guess I have to flash baseband again via Odin?
Great idea! On my 4.4.2 note 2, I think I'm experiencing the "multiple known networks" issue. I've got 4 vlans on my home WiFi (a full access network and a guest network on each band), so it's definitely that environment. Will be keeping this updated as it matures. Suck it, spy-guys!
thanks chain for defend the people privacy.Amazing app(LIKE ALL YOUR APPS).
Can you add mac randomization per each network
It doesn't work on my maguro with CM11. It FC after I try to activate it. Anyone managed to get this running on a Galaxy Nexus? 
well, flashed ROM, flashed modem again, and still no WiFi
worked well on a Stock but rooted LGE Nexus 5. Thx for that
+Muamer Seferovic I had a similar problem, I use a router with hidden SSID. I deleted the app and readded my wifi SSID and password and it works! It seems like this application delete saved networks 
+Chainfire, I've got the same issue as +Hamish Robinson. N4 w/CM11. If I turn PryFi, I can't connect to anything, even after re-adding the password. I'm currently not using Super SU, which might be the problem. I'll switch later and report if that changes anything. 
Jojsp G
+Chainfire in note 3. when py-fi is activate wifi no conect. 
+Muamer Seferovic flash your stock kernel, then your favorite kernel. You might have a Wi-Fi driver problem. Who knows, that might help and won't do any harm anyway. 
+Matthew Birck Not sure. I've personally tested on CM11 (on an S3) and that worked fine, and others have also reported it works on CM11. Nexus4 users have also reported success... what is the date of your CM11 ? 

+Jojsp G Which exact firmware are you using, and how did you flash it?
+David Gates Works on my Note2 running Omni. Not tested with stock firmware though.
Ok. I was just wondering. Went to download it and saw the not compatible warning. Running JellyBean build 21 I think. 
I tried it but my home wifi just returns with authproblems thus can't connect. Google Nexus 5
It killed my WiFi on my gs4. I had to reflash my ROM to get WiFi working again. 
+Chainfire, 20140131. Like I said I'll switch superuser apps later today, just in case that's it.
You are ruining the user experience. You'll understand some day. Knowing what you like or where you shop isn't a bad thing. It personalizes your experience.
Jojsp G
+Chainfire version de kernel
3.4.0-2019540, banda base DMJ7. Root and JB4.3.
I Flash it with ODIN
Working great on my Nexus 5
Jojsp G
+Chainfire careful not pry-wi is not a game you can damage the system. I have a note 3 in March pry-wi installed but did not work the wifi did not connect any network or localized, then I uninstall pry-wi and note 3 not connected the wifi kept on or off or was dead. turn off the phone and restarted and nothing worked, i had to take note of my wife tree prywi download to backup and spend my bluetooth-wi pry my damaged note reinstall or select the network and revived again forget. I like the idea of pry-wi but even in my note 3 does not work when I test it in full functionality and buy.
+Chainfire Enabled visible SSID, now working on both N7 and N4 (installed 1.02). On N4, I needed to re-add the network manually.
Great idea! But it don't work for me on my n4. Can't connect to any wifi when i turn it on:-( 
+Chainfire Is this or something similar planned to be integrated into omni?
Since you are a contributer and having this natively would be better that an app, isn't it? :D
on my Galaxy S3 i9300, your application stays at the detecting root vendor notice. Does not go beyond that. Even restarted the phone. Put off Wifi too. Any takes. 
Awesome Idea Chain! Nice. 
+Chainfire - CM privacy guard seems to be the problem. I turned it off and now everything works. I think.
Va no
So badically with this app you have no wifi whatsoever? My wifi toggle on N3 is greyed out after activating this app
Not compatible with HTC one x running android revolution hd 
Lance D
On my Note 3 stock 4.3 it just disables wifi. No hard crash thank goodness. Firmware N900TUVUBMI7 T-Mobile version.
Seem to work fine on Note3 with rooted stock kitkat. As usual I bought the pro version to show my appreciation. 
Awesome! If I use "go to war" at 15min intervals, will it waste battery? 
depends of frequency of your 15 mins I suppose
Chainfire...your the man.... Always love your works...I always install your app as long as supported my device.....and sometimes I really don't know what's the used...hehehe...but I'm confident using your apps because its you...your the man!
+Chad Riley yes doing this will increase power consumption of your device - by how much I cannot say without extensively testing it 
If one is using or protected by Tor and other deep stuff. Shouldn't that also protect your Mac address IMEI/ESN. If not, using pry- fi could fill that gap. So if your using Tor network does one still need pry fi or is it not needed or overkill?
+Cleveland Stamps tor does not conceal mac addresses it conceals your physical location from webservers - there is many reasons to do this the most obvious is to view something that is "not available in your region" - tors purpose is different to this and are used for different things - mac address flipping is useful to prevent the WiFi network admin profiling you - eg you connect do some browsing then flip macs and do more browsing - according to the network admin the sessions didn't originate from the same device - aka they are different people - the way its described WiFi can be used by retail outlets to data mine how you shop in their store - flipping mac addresses or appearing to be multiple people at the same time screws up their data profiling/mining - tor cannot possibly do this its for web anonymity jumping macs is giving you some (not complete) network anonymity 
Kev K
Think I'll give it a try. Awesome work by an awesome dev. Thanks chainfire!
Good looking ChainFire! Nothing but Respect for all of your countless hours you put in for our great community!
Thank you. 
Lance D
Just grabbed the update and disabled mac randomization. Still not working for me. 😟
"not compatible with your device" in play. Rooted Note 2, Verizon 
Would be great if it can do this with Bluetooth tracking as well. 
+Chainfire I think I will get the same answer you gave to +Mounib Al Rifai, but I prefer to be sure: since I'm playing Ingress, I'd like to know if I will have any issue with the game using your app... Thanks in advance for your help and great work!!!
Thanks man, already donated!
Well interesting Concept but I would insert a warning for all those non technical educated persons out there who just blindly try it. Changing the MAC Address every X Time randomly can have also a heavy impact on your infastructure and can cause you some big trouble with the company Network administrator team if you working in a major company. Especially BYOD enviroments are rely on a MAC static MAC Address.

I tried it yesterday and actually it's not working well currently. (Find5) It displays a MAC Change in the app but tracing the Wifi packages my device is still sending his original arp headers. Even in War mode a arp log just showed 1 change in 5 minutes. But as you said, just a proof of concept.
+Marco Götze Oppo's not working well has already been documented in the XDA thread (just as Sony's). I doesn't seem like that will change with app updates. It's unfortunate that there isn't really a way to detect this from the device itself though.
When you connect to some public Wi-Fi it will get your location from your phone's GPS before connecting 
I guess this is only for android
I have EchoeRom V14.1 and Pry-Fi 1.2 installed but Wifi connection can not established.
Thank you for your awesome work +Chainfire. Great idea & great app.. 
Nice, +Chainfire!  But why not randomized the MAC even for networks you do connect to?  For example, recently it has been revealed that airports track WiFi connections and sell it to governments.  So why not allow users to have randomized MAC addresses on WiFi connections as well, except for a "white list" (such as home networks that may have permissions based on MAC addresses).
Hieu Le
Nice app thank you 
I've got an error whereas Wifi Setting being disable and greyed-out. Pressing menu still can brought up Advance setting in Wifi but On/Off function totally greyed-out. The status stays disable for minutes until I disable Pry-Fi and reboot the phone. Wifi Setting function came back immediately. Running Stock Rooted Nexus4 with minimal mods - if not at all. Any recommend?
Actually, following +Chainfire directives, it's works. Again, N4/StockKitKat/Rooted/LTE Hibrid/Dalvik runtime
Quote "Turn Wi-Fi off, go into Pry-Fi -> Manage Networks, mark your network to "use original MAC", disable Pry-Fi, enable Pry-Fi, enable Wi-Fi, wait a minute, see if it works now."
I have attached v1.21-beta-test to the first post of the XDA thread that may also work for 4.0 and 4.1 Android firmwares. Let me know.
Still a little bug although it doesn't effect functional. 
A. Installed and activate service while Wifi is ON (Pry-Fi has been ON on pre-updated.) Installing and activating the app while Wi-Fi is ON has been causing Wifi Setting disable on previous version (mentioned on previous post). I wanna tried again with 1.21b hence installing the app while Wifi is ON.
Bug: Turn-On and Off Wifi will witnessed a double toggling by Android, both when turning On and Off. The toggle button on Top-right will double-toggling
Hi +Chainfire when i try to download it, play store says the app doesnt compatible with your device. My android is 4.1.2 on a motorola d3 
Hello +Chainfire , really nice idea! But I don't want to give proprietary software root privileges on my device. Ever thought of releasing this as free software? I know that you had a lot of work with this app and you have to pay your bills, too. How about crowd founding? That way ROMs could merge it and much more people could benefit!
+Guy Incocnito It's your own choice to give an app root access or not. If you don't want to do that, it wont work. I fail to see how any of that is my problem.
No work at my device acer iconia A 501 tablet
+Chainfire for some reason when Pry-Fi is enabled it won't allow me to connect to Wi-Fi. When I disable it I connect right away. Any suggestions? 
Works great with htc One and 4.4.2 and on my nexus 7 Lte too. Thanks 
+Chainfire I would love if you made a widget for this with a quick toggle to turn on and off... A pain and simple one :) great app and awesome work! 
+Chainfire I wish you were the  Google Android Team leader and Product manager :)
Hi Chain!
I can't download Pry-Fi in my Galaxy Note 2 with 4.2.1, rooted.

Isn't it compatible?
4.1.2 LG L9 II not compactible?
It doesn't seem to like pre-existing saved networks. I tried the method that +Chainfire mentioned earlier to correctly enable the app, however i couldn't connect to my saved wifi networks. I had to forget the networks from pryfi as well as the stock wifi and then re-enable the software in the correct order and then connect anew. S3/D2att w cm10.2 & 10.2.1.
lu zong
Once again, another great job you did here! Thanks alot and I hope you keep up the work.
zig mas
Note 10.1 N8000 not compatible
will there be an update for manually add the Mac Adress ?
There will be a complete overhaul very soon, in fact.
+Chainfire - mentioned this in the the XDA post but you could give the option to use only 'real' MAC addresses rather than random ones by lifting the patterns used from the macchanger source here:

The obvious benefit of doing this is that it makes it impossible for companies to filter their monitoring for invalid data which doesn't correspond to a real manufacturer. The address patterns can be found in:


Thanks again for working on this app :)
Hi Chainfire, don,t want to push, but any idea when the new version will come ?
greets, kriszty
It's #1 on my priority list right now, but I've overstrained myself, wrists and arms hurting, so no coding for me right now.
no problem, take it easy
greets and love from holland
Good soft but i can't download it :(, why don't upload to dropbox 
I found the app very useful, however I found a bug: I set up my network as WPA2 PSK and the app keeps forgetting the password, so every time I return home I need to manually write the password again.

Prior to that the network was set as WEP and it worked fine.

Is this a know issue? 
Will this defeat the wifi-pineapple's Karma mode? ie, does this app stop your phone from sending out SSID Probe requests?
I think this app is great! I should have expected something awesome like this from the creator of SuperSU.

Anyway, I just wanted to mention to everyone some suggestions (although this tip may already be in this very long thread).... if you run Pry-Fi and then find you cannot connect to your home wireless network, or any other Wi-Fi network that you previously joined, , follow the steps below:

1. Go into the settings=> Wi-Fi=>forget all previous networks.

2. Next, reboot into recovery.

3. While in recovery mode, do the following: (i) wipe cache; (ii) wipe Dalvik cache, and; (iii) fix permissions (located under the Advanced menu in TWRP).

4. Reboot your phone...It will take a few minutes, saying it is "updating" or "optimizing". Then go to Wi-Fi, and select the desired AP, and enter the authentication key.

Following the above steps should stop any connection problems you might have had, and also, you should you have any problems with your phone "forgetting" saved wpa keys either. 
Replying back to jacoy kiter your the lame 
Love this app and others from CF. But I do have a recurring issue with pry Fi on my g870a. After a few days of use it breaks my phone's WiFi, I am forced to Odin it every time this happens and having to redo everything on my phone is a huge chore, especially having to do it every few days. Is there anyway to keep it from breaking my WiFi? Thanks and keep up the truly amazing work!
I'm betting random reboots as well and my wifi is broken I am on a I9505 and I am running CM12. I need help this is my daily driver and it is nearly unusable because of this app. Please help!!! +Chainfire 
I am currently feeling like a complete idiot for not researching this app before using it and idk what to do.
It isn't the Apps fault. It probably is the phone itself. Just google for: Warranty bit 0x1
and for SIM not detected problem
Other users have this same issue after installing this app and I only got it after installing this app a few days ago.
and PS: Warranty bit 0x1 shows up when the Knox Warranty has been triggered and has nothing to do with this error.
Well, you could try uninstalling the App~
That's the only Thing. Since I have no Root Access on my Honor 6 Plus, I can't tell u that.
I've uninstalled it doesn't look but I don't think it wants to fix it self it's still happening I think the app modifies a config file or something and I might have revert it back manually.
Hello I've installed pry-fi and now my wifi won't turn on as normal. Even after uninstalling pry-fi. What can I do to fix it please? 
When I try to turn on the wifi it lights up dim and then goes back off. Help
Hey guys, if you have a Samsung there is a fix. Backup all your files first. Once you have backed everything up download your firmware for your phone from Put your phone in download mode and then flash the firmware using odin.
my pry-fi app has not been working for two weeks now whats going on
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