Mozilla telemetry in firefox installer – archived source

Each Firefox download has a unique identifier


Internet users who download the Firefox web browser from the official Mozilla website get a unique identifier attached to the installer that is submitted to Mozilla on install and first run.

The identifier, called dltoken by Mozilla internally, is used to link downloads to installations and first runs of the Firefox browser. The identifier is unique to each Firefox installer, which means that it is submitted to Mozilla whenever it is used.

While it is possible to download new installers each time a new Firefox version is released, it is also possible to use the downloaded installer again for that purpose.

A bug report on Mozilla’s official bug tracking website confirms the use of the download token. The linked document is not public, but the listing itself confirms the use and provides an explanation on why it has been implemented:

This data will allow us to correlate telemetry IDs with download tokens and Google Analytics IDs. This will allow us to track which installs result from which downloads to determine the answers to questions like, “Why do we see so many installs per day, but not that many downloads per day?”

According to Mozilla’s description, the identifier is used to analyze downloading and installation trends among other things.

The feature is powered by Telemetry in Firefox and it applies to all Firefox channels.

Interested users may verify the findings. One of the easier ways is to check the hashes of two or more Firefox installer downloads (the same version, language and architecture). Each hash is different. A search for dltoken using any hex editor reveals the string in the Firefox installer.

Firefox users who prefer to download the browser without the unique identifier may do so in the following two ways:

  1. Download the Firefox installer from Mozilla’s HTTPS repository (formerly the FTP repository).
  2. Download Firefox from third-party download sites that host the installer, e.g., from Softonic.

The downloaded installers do not have the unique identifier, as they are identical whenever they are downloaded.

Mozilla notes that the opt-out mechanism is the standard Telemetry opt-out. How users may opt-out before the installation of Firefox is unclear. A quick check of Chrome installers returned identical hashes each time.


Join the conversation

comment 169 comments
  • IvyPaido

    generic ivermectin

  • Richardpew

    propecia buy online canada

  • SuePaido

    vermox tablet

  • AshPaido

    fluoxetine 60 mg price

  • SamuelseaPs

    zestril tab 10mg

  • DarrylAbiva

    where can you get doxycycline

  • Michaeltef

    cost of retin a cream

  • ElwoodSem

    citalopram cost canada

  • IvyPaido

    how do i get propecia

  • ElwoodSem

    colchicine 500 mg tabs

  • Davistak

    phenergan 10mg uk

  • CurtisSmold

    zoloft 200 mg

  • IvyPaido

    neurontin 2018

  • SamuelseaPs

    international online pharmacy

  • ElwoodSem

    gabapentin 100mg cost

  • ozempic injections

    generic wegovy cost

  • wegovy tablets 7 mg

    wegovy semaglutide tablets 7.5 mcg

  • semaglutide cost

    ozempic tablets

  • wegovy weight loss

    rybelsus order

  • ozempic cost

    buy wegovy

  • semaglutide rybelsus

    buy ozempic for weight loss

  • semaglutide mexico

    semaglutide online order

  • semaglutide for weight loss

    ozempic coupon

  • rybelsus medication

    semaglutide from canada

  • rybelsus tablets buy

    semaglutide pill

  • wegovy 14mg tablets

    semaglutide buy uk

  • wegovy tablets cost

    buy semaglutide online canada

  • buy semaglutide canada

    semaglutide prescription

  • semaglutide tablet

    order ozempic online

  • semaglutide price

    order wegovy online

  • buy semaglutide

    wegovy prescription

  • buy semaglutide uk

    ozempic semaglutide tablets 3mg

  • buy semaglutide canada

    semaglutide prescription

  • semaglutide order

    rybelsus injection

  • semaglutide order

    buy semaglutide from canada online

  • wegovy sale

    buy rybelsus online from india

  • rybelsus tablets 7 mg

    buy rybelsus online no script

  • ozempic tablets buy

    buy semaglutide online no script

  • ozempic coupon


  • rybelsus online prescription

    semaglutide online cheap

  • wegovy weight loss

    semaglutide drug

  • order wegovy

    wegovy 14mg

  • rybelsus diabetes

    wegovy lose weight

  • semaglutide without prescription

    purchase semaglutide

  • rybelsus lose weight

    semaglutide diabetes medication

  • wegovy australia

    semaglutide 7 mg tablet

  • semaglutide generic cost

    wegovy prescription

  • rybelsus without prescription

    where to buy ozempic

  • order ozempic

    order rybelsus

  • order rybelsus

    wegovy online cheap

  • ozempic tab 7mg

    wegovy for sale

  • wegovy for sale

    semaglutide order

  • semaglutide sale

    wegovy 14mg

  • ozempic injections

    purchase semaglutide

  • wegovy over the counter

    wegovy price

  • semaglutide australia

    semaglutide injections

  • rybelsus online order

    rybelsus 14mg

  • wegovy 3mg

    wegovy tablets cost

  • buy ozempic uk

    semaglutide buy from canada

  • generic wegovy

    rybelsus canada

  • where can i buy semaglutide

    semaglutide canada pharmacy

  • semaglutide price

    semaglutide ozempic

  • semaglutide tablet

    wegovy online uk

  • wegovy tablets for weight loss

    buy semaglutide canada

  • rybelsus buy online

    rybelsus 7mg

  • wegovy 3 mg tablet

    wegovy online order

  • semaglutide online cheap

    [url=]wegovy semaglutide [/url]

  • rybelsus pill

    ozempic tab 14mg

  • wegovy uk

    rybelsus 14mg

  • rybelsus 14mg

    where can i buy ozempic

  • rybelsus 3 mg tablet

    semaglutide canada

  • wegovy

    buy semaglutide

  • semaglutide order

    semaglutide diabetes

  • rybelsus mexico

    semaglutide from canada

  • wegovy tablets 7 mg

    rybelsus semaglutide tablets 3mg

  • rybelsus buy australia

    generic wegovy

  • semaglutide prescription

    wegovy tablets for weight loss

  • rybelsus australia online

    purchase ozempic

  • rybelsus online uk

    buy rybelsus

  • buy semaglutide canada

    semaglutide for sale

  • ozempic injections

    semaglutide over the counter

  • order rybelsus

    wegovy online cheap

  • wegovy weight loss

    semaglutide order

  • wegovy buy from canada

    buy ozempic canada

  • where to buy semaglutide

    rybelsus 7 mg tablet

  • wegovy 7 mg

    wegovy over the counter

  • wegovy 7 mg tablet

    buy semaglutide online no script

  • rybelsus 14

    ozempic tablets

  • brand ozempic

    wegovy price

  • semaglutide diabetes medication

    rybelsus 14mg tablets

  • generic semaglutide cost

    semaglutide canada

  • wegovy where to buy

    semaglutide 7 mg tablet

  • rybelsus over the counter

    wegovy buy australia

  • metformin er 1000 mg

    metformin prescription cost in us

  • safe canadian pharmacy

    canadian pharmacy meds

  • synthroid 12.5 mg

    synthroid 0.025

  • how much is azithromycin 250 mg

    azithromycin brand name in india

  • price of lisinopril

    lisinopril online canada

  • cheap generic tadalafil 5mg

    best price generic cialis 20 mg

  • lisinopril average cost

    lisinopril 12.5

  • lisinopril pills

    zestoretic 20 12.5 mg

  • order semaglutide

    metformin singapore

  • buy synthroid 175 mcg

    synthroid 0.125 mg

  • purchase semaglutide

    top online pharmacy india

  • buy tadalafil india


  • semaglutide 7 mg tablet

    brand cialis online pharmacy

  • purchase wegovy

    can you buy synthroid over the counter

  • buying valtrex online

    buy valtrex online usa

  • ozempic tab 7mg

    best online pharmacy india

  • zestril 40 mg tablet

    zestril 10 mg tablet

  • how much is valtrex in canada

    cheap valtrex canada

  • synthroid 37.5 mg

    generic synthroid medication

  • semaglutide 21 mg

    medication lisinopril 20 mg

  • rybelsus 3 mg

    metformin purchase uk

  • online pharmacy 365 pills

    cheapest pharmacy canada

  • price of tadalafil

    tadalafil brand name in india

  • azithromycin online pharmacy canada

    azithromycin pills buy

  • lisinopril 40 mg price

    buy lisinopril 5 mg

  • ozempic

    lisinopril 20mg tablets

  • buy semaglutide cheap

    legitimate online pharmacy

  • tadalafil 20mg uk

    buy tadalafil 60mg

  • prednisolone prednisone

    prednisone over the counter australia

  • synthroid 0.05

    synthroid 0.0125 online

  • metformin 1500 mg

    metformin where to buy in uk

  • buy valtrex usa

    valtrex no perscrition

  • valtrex generic otc

    valtrex generic online

  • wegovy without prescription

    zestril 5 mg tablets

  • tadalafil india price

    buy tadalafil europe

  • canadian pharmacy sildenafil

    cheapest pharmacy for prescription drugs

  • synthroid brand name price

    synthroid 75

  • prinivil price

    lisinopril 12.5 mg

  • wegovy medication

    glucophage compare

  • zithromax 200mg

    azithromycin pills for sale

  • cost of 5 mg tadalafil pills

    tadalafil generic price in india

  • lisinopril pill 5 mg

    lisinopril 40 mg tablets

  • rybelsus mexico

    synthroid 0.0125 25mcg

  • semaglutide diabetes medication

    how can i get cheap cialis

  • semaglutide 14mg tablets

    world pharmacy india

  • lisinopril 5 mg uk price

    buy lisinopril without prescription

  • azithromycin mexico pharmacy

    azithromycin 500 mg pills

  • synthroid 0.175

    synthroid 0.125

  • rybelsus tablets buy

    canadian pharmacy generic viagra

  • semaglutide pills

    canada online pharmacy no prescription

  • wegovy online uk

    can you order lisinopril online

  • wegovy without prescription

    metformin how to buy

  • semaglutide pill form

    metformin 1000 mg canada

  • where can i purchase lisinopril

    where can i buy zestril

  • synthroid 225 mcg

    cost of synthroid medication in canada

  • generic tadalafil 20 mg price

    tadalafil online prescription

  • synthroid 05 mg

    cost of synthroid 175 mcg

  • legal online pharmacies in the us

    which online pharmacy is reliable

  • northern pharmacy

    rate canadian pharmacies

  • zestril 5 mg prices

    lisinopril 10 mg online

  • legitimate canadian mail order pharmacy

    internet pharmacy mexico

  • glucophage generic south africa

    metformin 500 price india

  • zestril 5mg

    lisinopril 20 mg pill

  • synthroid purchase online

    synthroid 1.37

  • tadalafil 40 mg daily

    tadalafil soft tabs

  • synthroid 0.112 mg

    buy synthroid online usa

  • online pharmacy price checker

    trustworthy canadian pharmacy

  • online

    advair diskus 500 50 mcg

  • price

    generic combivent prices

  • online

    amoxil antibiotic

  • tablets

    buy accutane europe

  • medication

    modafinil india online

  • online

    azithromycin 200mg price

  • pharmacy

    tretinoin 0.5 cream coupon

  • tablet

    augmentin 1000 mg

  • tablet

    vermox tablets uk

Comments are closed.