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Mozilla Trademark Policy

Version 1.0.1


This document outlines the policy of the Mozilla Foundation ("Mozilla," for short) regarding the use of its trademarks. Any use of any Mozilla trademark must be in accordance with this policy. As used in this memo, "trademarks" means not just Mozilla's logos, but also the names of its various products, as well as the names Mozilla and

The Mozilla trademarks include, among others, the names Mozilla®,®, Firefox®, Thunderbird™, Bugzilla™, Camino®, Sunbird®, Seamonkey®, Foxkeh™ and XUL™, as well as the Firefox logo, Thunderbird logo, SeaMonkey logo, Camino logo, Foxkeh logo and the Mozilla red lizard logo. As Mozilla registers others, it will update this policy.

Mozilla's trademark policy attempts to balance two competing interests: Mozilla's need to ensure that its trademarks remain reliable indicators of quality and security; and Mozilla's desire to permit community members, software distributors and others that Mozilla works with to discuss Mozilla's products and to accurately describe their affiliation with Mozilla. Striking a proper balance is a tricky situation that many organizations -- in particular those whose products are distributed electronically -- wrestle with every day.

Underlying Mozilla's trademark policy is the general law of trademarks. Trademarks exist to help consumers identify, and organizations publicize, the source of products. Some organizations make better products than others; over time, consumers begin to associate those organizations (and their trademarks) with quality. When such organizations permit others to place their trademarks on goods of lesser quality, they find that consumer trust evaporates quickly. That's the precise situation that Mozilla seeks to avoid -- especially since, when it comes to intangible products like software, trust is all consumers have to decide on.

Although Mozilla's trademark policy is composed of a number of specific rules, some contained in companion documents, most reflect the overarching requirement that your use of Mozilla's trademarks be non-confusing and non-disparaging. By non-confusing, Mozilla means that people should always know who they are dealing with, and where the software they are downloading came from. Websites and software that are not produced by the Mozilla Foundation shouldn't imply, either directly or by omission, that they are. By non-disparaging, we mean that, outside the bounds of fair use, you can't use our trademarks as vehicles for defaming us or sullying our reputation. These basic requirements can serve as a guide as you work your way through the policy.

Mozilla's trademark policy begins by outlining some overall guidelines for the use of Mozilla's trademarks -- including the names Mozilla,, Firefox, Thunderbird, Mozilla Suite and XUL, and the red lizard, Firefox, Thunderbird, Mozilla Suite logos -- in printed materials. It then addresses a series of more specific topics, including the use of Mozilla's trademarks on distributions of Mozilla's binaries, linking to Mozilla's website and the use of Mozilla trademarks in domain names. At various points, the policy links to other documents containing additional details about Mozilla's policies.

Mozilla also has a trademark policy FAQ as a companion document to this policy, posted at

Overall Guidelines for Printed Materials and Web Sites

Mozilla encourages the use of its trademarks in marketing, fundraising and other publicity-related materials. That includes advertising stating that a person or organization is shipping or selling Mozilla products. Of course, any use of a Mozilla trademark is subject to the overarching requirement that its use be non-confusing. Thus, you can't say you're raising money for Mozilla when you're actually raising it for a Localization Project, say that you're selling or reviewing the Mozilla Firefox Internet browser when you're actually reviewing a Community Edition of the Firefox browser, or use the Mozilla logos on the cover of your book or on your product packaging.

Although many uses of Mozilla's trademarks are governed by more specific rules, which appear below, the following basic guidelines apply to almost any use of Mozilla's trademarks in printed materials, including marketing, fundraising and other publicity-related materials, and websites:

  • Proper Form - Mozilla's trademarks should be used in their exact form -- neither abbreviated nor combined with any other word or words (e.g., "Thunderbird" rather than "T-Bird" or "Thunderbinary");
  • Accompanying Symbol - The first or most prominent mention of a Mozilla trademark should be accompanied by a symbol indicating whether the mark is a registered trademark ("®") or an unregistered trademark ("™");
  • Notice - The following notice should appear somewhere nearby (at least on the same page) the first use of a Mozilla trademark: "[TRADEMARK] is a ["registered", if applicable] trademark of the Mozilla Foundation";
  • Distinguishable - In at least the first reference, the Trademark should be set apart from surrounding text, either by capitalizing it or by italicizing, bolding or underlining it.

Software Distributions

Unaltered Binaries

You may distribute unchanged official binaries downloaded from to anyone in any way subject to governing law, without receiving any further permission from Mozilla. However, you must not remove or change any part of the official binary, including Mozilla trademarks. On your website or in other materials, you may truthfully state that the software you are providing is an unmodified version of a Mozilla application, keeping in mind the overall guidelines for the use of Mozilla trademarks in printed materials, detailed above. We suggest that, if you choose to provide visitors to your website the opportunity to download Mozilla binaries, you do so by means of a link to our site, to help ensure faster, more reliable downloads. (See the section on Linking, below.)

If you choose to distribute Mozilla binaries yourself, we request that you make available the latest stable version (of course, you probably want to do so as well). The notification requirements of the MPL have been met for our binaries, so although it's a good idea to do so, you are not required to ship the source code along with the binaries.

Official Localized Releases

Localization Teams that have been recognized by Mozilla may identify and distribute Official Localized Releases of the Firefox Internet browser and Thunderbird e-mail client using Mozilla's trademarks. Because Localization Teams and Official Localized Releases represent the Mozilla project, they are expected to abide by strict guidelines. For more information, please see Mozilla's Trademark Policy for Localization Projects.

Community Editions

Localization Teams and others that feel overly constrained by the guidelines regulating Official Localized Releases sometimes produce Community Editions of Mozilla products. Community Editions also are regulated by guidelines, though they are not as strict as those governing Official Localized Releases. Given that Community Editions are not as strictly regulated as Official Localized Editions, they cannot be distributed under the Mozilla name or trademarked Mozilla logos, and must be identified as Community Editions. For more information, please see Mozilla's Trademark Policy for Community Editions.

Serious Modifications

Those taking full advantage of the open-source nature of Mozilla's products and making significant functional changes may not redistribute the fruits of their labor under any Mozilla trademark. For example, it would be inappropriate for them to say "based on Mozilla Firefox". Instead, in the interest of complete accuracy, they should describe their executables as "based on Mozilla technology", or "incorporating Mozilla source code." They should also change the name of the executable so as to reduce the chance that a user of the modified software will be misled into believing it to be a native Mozilla product.

Extensions, Themes and Plugins

At the same time as it seeks community involvement in the development of its products, Mozilla wants to protect the reputation of its products as high-quality and lightweight, with simple, usable interfaces. If you want to ship extensions, themes or plugins installed by default or as part of the same installation process as the Mozilla products (as opposed to, say, linked as XPIs from the default start page), and you plan on distributing them under any Mozilla trademarks, you must therefore first seek approval from Mozilla. What Mozilla finds acceptable will depend on the effect of the extensions, themes and plugins on the Mozilla product. To give examples, changing the theme of one product to another, equally high-quality and aesthetically pleasing theme would probably be approved. A combination of ten different extensions with three toolbars and seven context menu items probably wouldn't be.

Related Software

Mozilla products are designed to be extended, and Mozilla recognizes that community members writing extensions need some way to identify the Mozilla product to which their extensions pertain. Mozilla's main concern about extensions is that consumers not be confused as to whether they are official (meaning approved by Mozilla) or not. To address that concern, Mozilla requests that extension names not include, in whole or in part, the words "Mozilla", "Firefox", or "Thunderbird" in a way that suggests a connection between Mozilla and the extension (e.g. "Frobnicator for Firefox," would be acceptable, but "Firefox Frobnicator" would not).


So long as you don't do anything that might confuse visitors to your website, or that might violate the Overall Guidelines for Printed Materials, above, Mozilla invites you to link to Mozilla's website, including for the purpose of allowing your visitors to download the Mozilla Firefox Internet browser and Thunderbird e-mail client. Mozilla even provides the banners and buttons to facilitate the download of Mozilla software:

The only exception to this policy is for site icons (favicons). If you plan to use a Mozilla trademark as a site icon, you need to request permission. Also, please remember that Mozilla disapproves of and does not provide "Best Viewed With" buttons, when used in connection with the Firefox Internet browser; Mozilla believe the web is best viewed with any standards-compliant browser.

Domain Names

If you want to include all or part of a Mozilla trademark in a domain name, you have to receive written permission from Mozilla. People naturally associate domain names with organizations whose names sound similar. Almost any use of a Mozilla trademark in a domain name is likely to confuse consumers, thus running afoul of the overarching requirement that any use of a Mozilla trademark be non-confusing. If you would like to build a Mozilla, Firefox Internet browser or Thunderbird e-mail client promotional site for your region, we encourage you to join an existing official localization project.

To receive written permission, please download and follow the directions as outlined in the Domain Name License.

Services Related to Mozilla Software

If you offer services related to Mozilla software, you may use Mozilla's trademarks in describing and advertising your services, so long as you don't violate these overall guidelines for the use of Mozilla's trademarks or do anything that might mislead customers into thinking that Mozilla has any direct relationship with your organization. For example, it's OK if your website says, "Internet browser customization services for Firefox available here." It's not OK, though if it says, "Firefox Internet browser customization services sold here," or "custom Firefox Internet browsers available here," since the first suggests that Mozilla is related to your business, and the second is confusing as to who -- you or Mozilla -- performed the customization. When in doubt, err on the side of providing more, rather than less, explanation and information.

Logos and Merchandise

When it comes to Mozilla's trademarked logos ("logos," for short), there are some cool things you can do and some cool things you can't do - at least not without asking Mozilla.

You may make t-shirts, desktop wallpaper, or baseball caps with Mozilla logos on them, though only for yourself and your friends (meaning people from whom you don't receive anything of value in return). You can't put the Mozilla logo on anything that you produce commercially -- at least not without receiving Mozilla's permission. Of course, Mozilla owns and operates the Mozilla Store, which sells a wide range of CDs, Guidebooks, T-shirts, and products with Mozilla software and logos. That's how we make some of the money that keeps us around.

There are two additional broad categories of things you can't do with Mozilla's logos. The first is to produce modified versions of them. A modified logo also would raise the possibility of consumer confusion, thus violating Mozilla's trademarks rights, too (remember the overarching requirement that any use of a Mozilla trademark be non-confusing?). The second concerns high-resolution copies of Mozilla logos, which you cannot have or use. If you've a very good reason to seek an exception to the rule against having and using high-resolution copies of Mozilla logos please contact the Mozilla Corporation for Firefox and Thunderbird, or the Mozilla Foundation for other logos.


Mozilla has tried to make its trademark policy as comprehensive as possible. If you're considering a use of a Mozilla trademark that's not covered by the policy, and you're unsure whether that use would run afoul of Mozilla's guidelines, feel free to contact us and ask. Please keep in mind that Mozilla receives lots and lots of similar questions, so please review all available documentation, including the Frequently Asked Questions (FAQ) before contacting us.