DataFox is a bandwidth usage monitor for BSNL’s DataOne and MTNL’s TriBand broadband services. DataFox is a cross platform extension written for Firefox and Google Chrome; if you use Internet Explorer or any other browser, DataFox will not work for you. Tough shit. Version 1.9.5 is compatible with Firefox versions 1.5 – 15 and supports BSNL sites (including and and both MTNL Bombay/Delhi sites (including

DataFox in action on the Firefox status bar…

menu tooltip
DataFox context menu DataFox tooltip

DataFox in Google Chrome

Download, Installation & Updates

If you’re using Firefox, click here to install the extension directly. Alternatively, right click, choose Save Link As… and save the XPI file locally. Open this file in Firefox (File > Open File…) to complete the installation. DataFox has been tested with Firefox versions 1.5 to 8. To activate this extension, you need to restart Firefox. Firefox might show you a message at the top of this window, saying it prevented from asking you to install an extension. Click the Options button in the message and then click Allow in the dialog that shows up. Click the link again to install.

To update, go to Tools > Add-ons and select DataFox in the list. Right click to bring up the context menu. Select Find Update. Firefox will connect to my update site and inform you if an update is available. If one is, click Install Updates and you’re done.

If you are using Google Chrome, click the Install button on this page.


DataFox is really easy to use. Once installed, you should see this icon () in your status bar. Click it to bring up the login dialog. Select your ISP, then enter your name and password and click the Login button; that’s it. Click the icon again to refresh the usage data. Since version 1.4, if you keep CTRL pressed when you click this icon, DataFox will display details from the most recent successful update. This can come in handy if the usage server is down and you’d like the previous details restored.

DataFox works by obtaining usage information directly from the BSNL / MTNL usage site, it does not monitor your network in any way, so usage details probably won’t change until you logout of DataOne / TriBand and log back in again. BSNL users may want to use the Override default domain option in the login dialog in case the BSNL server you are being directed to is not responding (see below for explanation). Users who normally use to check their usage must check this option and select the corresponding domain from the domain list. MTNL users, if the usage server is down, DataFox will not be able to fetch any usage records.

You can right click the status bar icon to bring up the following options:

Update Forces the usage data to update, has the same effect as clicking the icon.
Logout Allows you to re-enter your account details the next time you update.
Show Records Display your usage records in the browser, you may choose to see records of either the active month, or the selector for all months.
Month (BSNL Only) Choose the month for which usage data is fetched. DataFox will allow you to choose one of six months as this is the extent of the records available online. In case data for a month does not exists (say, if you have only been using DataOne for three months) then DataFox will display an error message when trying to fetch the usage info.
Preferences Brings up the DataFox preference dialog (see below). Can also be invoked from the Tools menu.
Login Dialog options:Override default domain (BSNL Only) By default, DataFox first queries for the appropriate address at which your usage can be checked. I assume it sends you to a server in your region for the quickest response. In case you wish to specify your own address or in case the redirect is not working for some reason, check the box and choose an address from the list or enter your own. users (those with IP addresses in the range 117.*.*.*) must check this option and select from the domain list, DataFox will not work for you otherwise. In the username field and password fields, you must enter your 14 digit portal Id and corresponding password; these are different from the username and password you use in your dialer / modem / router.


Login on startup:

If this is checked and you have a password saved, DataFox will attempt to log in to your ISP’s site and show you the most recent usage details. If unchecked, DataFox will display cached details on startup.

Bandwidth limit:

If you’re using DataFox, you’re most likely on a bandwidth limited plan. Entering your limit here will enable DataFox to display a progress bar indicating the percentage of bandwidth (for the current month) consumed. DataFox will also be able to tell you if you are danger of reaching your limit before the month ends and how much “surplus” bandwidth you have for the current day. If you do not enter your limit, none of these statistics will be available.

Statusbar / Tooltip string:

DataFox parses the data returned from your ISP, makes some calculations and places the results in several variables…

[BSNL]{tS}-Total Upload
[Both]{tR}-Total Download
[BSNL]{tX}-Total Transfer
[Both]{cX}-Chargeable Transfer
[Both]{sX}-Surplus Transfer (for today)
[Both]{rX}-Remaining Transfer (for the month)
[Both]{uP}-Used Percent
[Both]{aP}-Allowed Percent
[BSNL]{tH}-Total Hours
[Both]{tT}-Last Updated

You can place any text in the Statusbar string or the Tooltip string, and DataFox will replace any variables in the text with their actual values.

An example: I’ve transferred 2 GB in all but only 1.5 GB if the night transfer is excluded. So the string “{tX}GB / {cX}GB” will produce “2.0GB / 1.5GB”.

Progress page:

This page controls the colors used by DataFox under different usage conditions. If you do not specify your Bandwidth limit preference page, only the Usage OK colors will be used. On the other hand, if you do specify the limit but still do not want the progress bar to appear, you can simple uncheck the enable box.

How DataFox tracks your bandwidth use

Note: The following only applies if you have specified your bandwidth limit.

Let us assume you have 6000MiB of transfer for the month, and you’re in the month of June (which has 30 days).

DataFox will calculate that you have 6000/30 = 200MiB of transfer available per day (let’s call this TPD); assuming that you’re using your bandwidth at a regular rate. This means, on the 1st of the month, you’re allowed 1*TPD = 200MiB and on the 5th of the month, your usage could go upto 5*TPD = 1000MiB and you’d still be within limits.

Allowed Transfer = date * TPD
Surplus Transfer = Allowed Transfer – Chargeable Transfer (Chargeable Transfer is the actual bandwidth that is recorded by your ISP and deducted from your bandwidth cap – this is the figure you usually keep track of).

Now, if your Surplus Transfer is negative, DataFox puts your usage in the Overlimit category and the Overlimit colors will be used for the text and the progress bar. If your Surplus Transfer is positive, your usage is OK and a different set of colors is used. It is important to note that the Surplus transfer is not the difference between your monthly limit and the amount used till date. It is the difference between the allowed usage on that date as calculated by DataFox and your actual usage.

IllustrationBandwidth limit: 6000MiB, Nr. of Days in month: 30, therefore TPD = 200MiB.
On the 5th:
Chargeable Transfer as recorded by your ISP 850MiB
Allowed Transfer as calculated by DataFox 5 * TPD = 1000MiB
Surplus Transfer = Allowed – Chargeable 1000 – 850 = 150MiB(OK)
On the 15th:
Chargeable Transfer as recorded by your ISP 3300MiB
Allowed Transfer as calculated by DataFox 15 * TPD = 3000MiB
Surplus Transfer = Allowed – Chargeable 3000 – 3300 = -300MiB(Overlimit)
On the 29th:
Chargeable Transfer as recorded by your ISP 6500MiB
Allowed Transfer as calculated by DataFox 29 * TPD = 5800MiB
Surplus Transfer = Allowed – Chargeable 5800 – 6500 = -700MiB(Overlimit)

DataFox is also capable of calculating the allowed usage on an hourly basis instead of on a daily basis (see the Daily / Hourly radio buttons on Progress preference page).

Here DataFox calculates a TPH figure as 6000 MiB / (30 * 24) hours = 8.3MiB per hour. At 2pm on the 5th of the month, 4 * 24 + 14 = 110 hours have passed. Your allowed usage at this time is: 110 * 8.33 = 916.3MiB.

The remaining calculations are the same. I programmed this in before the daily mode and then I realized this was probably too accurate to be useful, so I made the daily mode the default.


Version 0.8 
  • Initial verision suppports BSNL DataOne only.
  • Basic tooltip and statusbar preferences.
Version 0.85b 
  • Support for MTNL TriBand.
  • Multi-window awareness.
  • Ability to execute Javascript in tooltip and status bar strings.
  • Login on startup optional.
Version 1.0 
  • Progress bar.
  • Bandwidth limit awareness, tracking and reporting.
  • Preference changes take effect immediately.
  • New preference for data unit and decimal point accuracy.
Version 1.0.1
  • Bugfix: BSNL bandwidth limit awareness.
  • Bugfix: MTNL Bombay Session Records.
Version 1.2
  • Bugfix: Rounding error could cause progress meter to display wrong color.
  • Firefox 3 beta 4 support added, many FF3 related fixes.
Version 1.4
  • Support added for new BSNL portal (
  • DataFox will now cache results automatically.
Version 1.5
  • Works with update (~ July 2008), consumes much less bandwidth.
  • Code cleanup: Global variables significantly reduced, better Firefox citizen.
Version 1.7
  • Works with
  • Works with MTNL Bombay site for ‘@’ users (
  • New variable {rX} added for remaining transfer.
Version 1.7.5
  • Works with update (~ May 2009).
  • Miscellaneous minor fixes.
  • Bumped max Firefox version to 3.5.*.
Version 1.9
  • Works with update (~ November 2009).
  • Works with MTNL Bombay update for ‘@’ users (~ July 2009).
  • Bumped max Firefox version to 3.6.*.
Version 1.9.2
  • Works with update (~ June 2010).
  • Compatible with Firefox 4
Version 1.9.3
  • Compatible with Firefox 6
Version 1.9.5 (Current)
  • Support for
  • Compatible with Firefox current Firefox versions.

Coming up

  • Daily progress mode.
  • [Insert your favourite feature here – send me feature requests].


The Source:

There are many people concerned about the safety of their logincredentials. This is a fair concern, so let me try to allay your fears. The XPI file you downloaded is just a zip file. Decompress it to find a JAR file (which is also just a zip file) in which you will find all the source behind DataFox. It’s just basic JavaScript and XML, and it won’t take a rocket scientist to figure out your account details are going only to the BSNL / MTNL servers. It would be impossible to hide any password stealing code in what is essentially open source project – the code is available under GPLv2 (there is no separate download, just follow the steps above to get to the source). Besides this, DataFox has been in use for two years by tens of thousands of users, if there was something fishy going on, it would never get this popular and everyone and their grandmothers would know about it.

Saved Passwords:

If you save your passwords, DataFox uses Firefox’s password store to store them. Go to Tools > Options > Security and click Show Passwords…. Look for all entries where the site is “chrome://datafox/” – you can delete or view those passwords as you please.

Contact & Support

I’m Brian Fernandes, see the About page for contact details; comments and feature requests welcome. Join other DataFox users in the DataFox thread at the India Broadband Forum. More info may be found at the DataFox wiki page.

Special thanks to Apoorv, Arnav, Gavnit, mrbgupta, Netfreak, Rohit, Seshu, Sunish and Vrushank who have sent me their passwords, without which DataFox would only work for BSNL’s old portal. Essbebe has helped collate information on the new portal, making my job much easier. Sushubh for running the India Broadband Forum which is the place to discuss DataFox related issues.

  1. #1 by anbarasan on September 6, 2009 - 9:27 AM

    It is an very good usage addon.Thank you

  2. #2 by jj on September 12, 2009 - 9:01 PM

    one of the best and useful plugin for bsnl broadband users.thank u so much.keep up the good work

  3. #3 by Rishi on September 13, 2009 - 4:06 AM

    hello….i am not able to LOGIN in this addon….plzz help me out..i have got bsnl m living in rajkot..gujarat….i had tried before but it dint worked…wt could be the reason..i hav cheked everythin bt no result…so plzz helo me out cuz i am in very muc need of this addon….thank you

  4. #4 by t.p.anandhan on September 15, 2009 - 8:19 AM

    It is an very good usage addon.Thank you

  5. #5 by Ashank on September 16, 2009 - 4:55 AM

    Hi guys, pls tell if something same is avaliable for google chrome too

    • #6 by Brian on October 5, 2009 - 5:05 PM

      Ashank, no plans for a Chrome version; nothing like DataFox is available for Chrome right now either, sorry!

  6. #7 by sandeep on September 28, 2009 - 12:43 PM

    waiting for update ….does not work on firefox 3.5.3
    cant do without it……..

    • #8 by Brian on October 5, 2009 - 4:59 PM

      Sandeep, DataFox works just fine with FF 3.5.3 and should work with all versions FF 3.5. I will be updating it to add support for 3.6 as well.

      Are you using (if you are a 117.* series user)? is no longer operational, you need to switch to if you were using

      Also check if you can login to the site and check your usage. If you can, but DataFox can’t, please let me know.

  7. #9 by sumit asok on September 30, 2009 - 4:13 PM

    Hi, i am getting error ” DataFox: usage data N/A” – i am under plan 2.5gb Download/Upload limit…please help me…i did change the default IP address to ( which is how for me. )
    Nice work & useful too…

    • #10 by Brian on October 5, 2009 - 5:06 PM

      Please see my about page for my contact details and email me – are you able to check your usage if you go to the site directly?

  8. #11 by mriitunjay on October 3, 2009 - 11:01 AM

    Was working till august end, has suddenly stopped working, and Idea what could be the problem. It is not accepting the current login id and password.

    • #12 by Brian on October 5, 2009 - 5:02 PM

      Try to use those same credentials on the usage website, directly in a browser. Can you login? Is it showing you the details of the months you want?

      Please note that is no longer operational, you need to use now and can select that in the Login dialog under “Domain override”.

  9. #13 by mrbgupta on October 6, 2009 - 1:28 AM

    Hello Brian, how are you?Hope everything is running well.

    Facing a small problem, when I right click and select show records>active month nothings happens.To be particular, a new tab opens but the portal page with me logged in automatically no more opens, only a blank page.

    You have named few people thanking them,lol mistyped my name as ‘mbgupta’ instead of ‘mrbgupta’.
    Anyway don’t search me @IBF because I have left it long ago due to personal reason.This was my first visit to your site.Keep it up buddy!

  10. #14 by aju on October 19, 2009 - 4:38 PM

    Datafox is currently not working for the users of Mtnl Triband mumbai who have thier login userid as
    I think it is becoz they have updated the login website for
    “Telephoneno@a” users.
    Is it??
    Pls provide an update for datafox resolving this problem

    Datafox works great. Keep up the good work……

  11. #15 by Venkatesh on October 29, 2009 - 6:38 AM

    At the outset this is a much needed software. Thanks! I recently reformatted my hard drive after backing up datafox with mozbackup. But on restoring all addons, I found that Datafox icon is not displayed in the status bar although it is enabled in the addons list. Simple thing would be to reinstall it of course but was wondering what the reason for this behaviour.

  12. #16 by sharma on November 11, 2009 - 4:52 AM

    i have just installed datafox but it isn’t logging me in my bsnl account.
    plz help me in choosing domain, i have tried all but no one worked
    i am doubtful about username if it should be portal id or bsnl service username.
    usually i check usage on but the same is not working on datafox
    plz help….

    • #17 by Brian on November 12, 2009 - 2:17 PM

      Sharma, you should use the credentials you use on Use the 14 digit portal Id for the user name and set the domain to

  13. #18 by Avinash on November 14, 2009 - 1:06 AM

    Hai There……

    This is Avinash….
    I’m Using Datafox to check my Usage….
    Now I need to know,do this Plugin carry any of my personal data like saved passwords,visited site list…etc….

    Atlast can u give me ur source code for educational purpose…..
    Currently I’m doing my Btech and very much Intrested in the source code……..
    Please do reply for this comment as soon as possible

  14. #19 by Arun kumar on November 18, 2009 - 8:40 PM

    Hello Brian,

    thanks for providing such a wonderful piece of S/w. i have been using your Datafox since a month with no problems. but since past few days the datafox is unable to show usage records. when i checked domain it is showing “portal 6.1” message i,e it doesn’t show the usage records. it gives info about how to manage a website on bsnl domain.

    any idea about this problem.


  15. #20 by AKSzy on December 2, 2009 - 4:06 PM

    Hi Brian,

    I’ve hav been using datafox for long time..but nw when i installed firefox 3.6, am not able to add datafox to it.:(..
    Please make it compatible with firefox 3.6 sooooooon…..

  16. #21 by Musa Gulab on December 15, 2009 - 11:13 AM

    Great addon. Please update for FF 3.6

  17. #22 by Ayyamperumal on December 20, 2009 - 11:10 PM

    Wonderful add on for data one users. Thanks.

  18. #23 by balaji on December 29, 2009 - 12:13 AM

    datafox got updated and it has started working again

  19. #24 by smc on December 30, 2009 - 12:53 AM

    great , now working with updated bsnl site.

    i have a feature request-
    can variable/string for last stop time [last record time] can be added, as bsnl does not get updated regularly, sometimes even for many days. last update time show time of my update not the last record time.

    • #25 by Brian on December 30, 2009 - 11:52 AM

      Good idea, but requires a significant amount of additional work – will definitely keep it in mind for the next version.

  20. #26 by Himannshu on December 30, 2009 - 8:12 PM

    Seasons greetings. I like the way u take up challenges. God bless you.

  21. #27 by karthik on December 31, 2009 - 1:01 PM

    Great work buddy!!..Nice addon.Really helped me,or for that matter for all BSNL users.

  22. #28 by ramanuj on January 2, 2010 - 12:51 AM

    Thaks brian 4 the updated datafox
    For almost a month ,i lost a lot of my usage 4 checking them

  23. #29 by Commando07 on January 3, 2010 - 3:39 PM

    Thnx a lot for the update 😀

  24. #30 by Mister on January 8, 2010 - 2:50 PM

    Brian, plz inform the users on IBF and datafox page of that you’ve updated the plugin. I don’t think they know.

    Thank you and Good wishes

  25. #31 by Vinay on January 17, 2010 - 9:36 AM

    Thanks dude.. great work…

  26. #32 by Ajith C on January 18, 2010 - 10:55 AM

    thanks for the good addon

    1.7.5 is the version available at

    BSNL site got some updates recently, since then 1.7.3 stoped working.

    Curent 1.9 works with bsnl sites. Will you update it at firefox adons site.

    • #33 by Brian on January 20, 2010 - 12:55 PM

      Version 1.9 has been submitted to AMO, but currently there is some back & forth going on in the approval process. I have not had the time to look into this, but will do so shortly. Thanks for the reminder!

  27. #34 by Vikram on January 22, 2010 - 7:34 AM

    Thank you very much. This program is a true lifesaver. Now if I could only learn to limit myself, even after this my monthly bills would really go down.

  28. #35 by dipen on January 22, 2010 - 7:22 PM

    Thanx a lot. good one.

  29. #36 by Vigneshwaran on January 26, 2010 - 6:49 PM

    Hey brian, you have to develop a chrome extension soon.. A lot of bsnl broadband users switched to chrome as Adblock and Flashblock is available for chrome since today. So it would be gr8 if u create a chrome extension. Please create one.

  30. #37 by Pinak ahuja on February 3, 2010 - 11:56 AM

    Dear Brian,
    excellent addon i must say.
    the new beta version of chrome supports extensions hope you could design this addon for it please.

  31. #38 by Kiran on February 5, 2010 - 2:36 PM

    Dear Brian,
    Thank You very much for such a lovely addon. Probably the most useful addon!
    It would be gr8 if this addon was available for other browsers too!

  32. #39 by shyam on February 10, 2010 - 6:15 AM


    I tried to use Datafox . It works fine on vista , but didnt work with my firefox on windows 7. Not sure if OS has any effect on the add on , but there is no difference between the firefox browsers and it works with VIsta only…

    PS: 0 .88 GB over this month.. 20 days with .12 GB left.. this software add on might just save my ass ..thanks boss

  33. #40 by Robin Parriath on March 2, 2010 - 11:24 AM

    Hi Brian,

    Thanks a lot for a wonderful add-on. It is a real time saver.

    There seem to be some complaints by people about BSNL data usage not showing. It really isn’t a problem with the add-on. It is in-fact, the problem with the data on the BSNL site not being updated real-time.

    Keep up the good work!

  34. #41 by Satish on April 23, 2010 - 6:27 PM

    Will it work on Linux Debian based operating systems??

  35. #43 by K Vinod Kumar on May 4, 2010 - 7:37 PM

    Thanks a lot Brian. It is really a killer app.

    Keep going.

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