Privacy Notice for the Public Network

Updated 27 May 2021

About Stack Overflow

The Stack Overflow Network (also referred to herein as “Stack Overflow” or “Network”) is a set of related Internet sites and other applications for questions and answers, owned and operated by Stack Exchange, Inc. (“Stack Overflow”, “we” or “us”), a Delaware corporation.

Stack Overflow welcomes you to the Network, the largest community of developers in the world, and invites you to participate in the community by sharing knowledge with your peers and colleagues.

This Privacy Notice is applicable to you when you participate in our Community by interacting with us through Stack Overflow’s Public Question and Answer Network (“Public Network”).

Here you will find details about the personal information we collect about you when you use the Public Network, how and why we collect it, how we use it, and how we keep it secure. This Privacy Notice also tells you about your rights, how you can exercise those rights, and how the law protects you.

Stack Exchange Inc. is the controller responsible for your personal data.

If you have any questions about this Privacy Notice or the way we use your personal data please contact us at

About the Public Network (Question and Answer Content)

The Public Network allows individual users to engage in a community to share their knowledge and expertise, and to acquire knowledge and expertise. It is community-moderated, and the content in the Public Network is public and therefore visible for anyone to see and is subject to our Public Network Terms of Use.

When you use the Public Network, we will collect the information set out below:

The data we collect about you

We collect the information that is necessary to conduct our business, to provide the services you have requested and to keep you informed. We may also use the information you provide to communicate with you about our products and services. We may share your information with third parties in order to provide you with such services or where we are required to by law or have another legal basis to do so.

We may collect, use, store and transfer different kinds of personal data about you which we have grouped together as follows:

  • Identity Data: including username or similar identifier.
  • Contact Data: including delivery address, email address, and telephone numbers.
  • Technical Data: including internet protocol (IP) address, your login data, traffic data, browser type and version, time zone setting and location, browser plug-in types and versions, operating system and platform and other communication data which gives us information about how you accessed our website.
  • Profile Data: including your username and password, your interests, preferences, feedback and survey responses.
  • Usage Data: including information about how you use our website, products and services.
  • Marketing and Communications Data: including your preferences in receiving marketing from us and your communication preferences.

You may choose to provide certain "special category" data about you (such as data about your race or ethnicity, religious or philosophical beliefs, sex life, sexual orientation, political opinions) in connection with your use of our Public Network. If you do, we will hold and process this data in accordance with our privacy policy.

More details about how we use this data is provided below:

We collect information such as your username, password, email address, IP address (collected at each site visit).

This information is also used to identify individual users to the Public Network and to award activities and attribute them to you. Your username and additional content you provide including your profile picture, question and answer content, and your reputation are visible publicly.

When you register for a Stack Overflow account, we collect your name and email address, your username and any additional information you provide. We will generate a unique identification number that we will use to recognise you when you are signed in.     

Moderators, who have elevated access privileges, may access non-public user profile data as well as content in posts and other public data. For more information about moderators and their role in the Stack Exchange Network, please visit: /help/site-moderators.

Other account information and usage information including your IP address and browser data may be used for diagnosis, security and Product and Service optimization.

You should not include any financial information or other information that you do not wish to make public when using our Public Network which is a public website. We do not collect such information. It is your responsibility to keep such information safe and secure.

Can I revoke permissions once I have put information on the Public Network?

Please be aware that when using the Public Question and Answer Network, you cannot revoke permission for Stack Overflow to publish and to allow others to have derivative rights to such public content once it is made public.

The content you contribute on the public network is public, in perpetuity, and Stack Overflow loses direct control over such content when it is published on the open internet. This also means that if you post personal information about yourself, you do so at your own risk, including the risk of abandoning any privacy rights you had in such information. However, we can work with users to remove any personal data that has been posted in error or which a user wishes to remove.

Additionally, from time to time, Stack Overflow makes such public content available via compilation via the Creative Commons Data Dump and by providing public content to the Stack Overflow Network. You should be aware that such content, once public, cannot often be removed from public view even if it is removed from the Stack Overflow network and our servers.

How is your personal data collected?

Generally, we collect personal information related to you when you interact with us on our Public Network.

We collect data in the following ways:

  • Direct interactions: you may give us personal information by filling in forms or by corresponding with us by mail, phone, email, in person at events, as part of our contractual arrangement with you, or by inputting that data into one of our customer facing platforms. This includes personal data you provide when you order or express an interest in our products or services; subscribe to our services or publications; request marketing to be sent to you; enter a competition, promotion or survey; or give us some feedback.
  • Personal data we generate about you e.g. through automated technologies or interactions: when you register for a Stack Overflow account, we will assign you a unique identification number that we use to recognise you when you are signed in to our platform.  We may automatically collect technical data about your equipment, browsing actions and patterns when you interact with our website.  We collect this personal data by using cookies, server logs and other similar technologies. We may also receive technical data about you if you visit other websites employing our cookies.
  • Telephone or product demonstration conversations which may be recorded by us to help us improve our training and quality
  • Third parties or publicly available sources: we may receive personal data about you from various third parties and public sources including: social media platforms, our own corporate prospect/customer databases or online research referrals.

How we use your personal data

Purposes for collecting and using personal information

We use the above categories of personal information for the following purposes:

  • To verify your identity and enable you to access your or your organization’s products and services when you contact us or access our services.
  • To protect you from fraud and for fraud prevention and detection.
  • To provide commercial quotes to you, e.g., when you enquire about a product or service.
  • For statistical analysis (e.g. on the use of our websites).
  • To operate and improve our websites and services.
  • To notify you of any changes to our websites or our services and products which may affect you.
  • To provide you with technical and customer support.
  • To ask your opinion or feedback on our services or surveys.
  • To communicate with you about other Stack Overflow products or services, events, offers, promotions and other information or news that we think may be of interest to you. Whenever we communicate with you in this way, we will give you an opportunity to opt out of receiving future messages. 
  • To enforce our legal rights or comply with legal requirements.
  • To provide improved website and product experience and communications informed by your product subscriptions and/or data collected.

We will only use your personal data when the law allows us to. We will use your personal data in the following circumstances:

  • Where we need to perform the contract we are about to enter into or have entered into with you.
  • Where we have your consent. You can withdraw your consent at any time.
  • Where we need to comply with a legal or regulatory obligation.
  • Where it is in our legitimate interests, including our commercial interests in operating the Network and Stack Overflow Platforms.

Whenever we rely on legitimate interests for processing, we ensure that we consider and balance our interests against the individual’s interests before processing. We do not use your personal data on the basis of legitimate interest for activities where individuals’ interests override our interests


Stack Overflow emails use Javascript for email tracking of opens, clicks, and unsubscribes or may contain a small, invisible, one pixel image which can be used to let us know when the email is opened or forwarded. If the email recipient has images enabled on their device, when the email is opened, a message (an automatic request) is sent to Stack Overflow’s server requesting the image. That request is logged by Stack Overflow and tells us that the email has been opened. A similar process may be used in relation to links or attachments in the email, with a request being sent to Stack Overflow for the content that is accessible via the links or attachments, thus telling Stack Overflow that the link or attachment has been accessed.

Who do we share your personal data with?

We may share your personal data with companies within the Stack Overflow and other parties detailed below. We may also transfer your personal data outside of the European Economic Area (EEA), but only when specific safeguards have been put in place in order to protect your personal data.

We may share your personal data with one or all of the following:

  • Stack companies incorporated in Germany and the UK ; and
  • External Third Parties as follows:
    • Suppliers who we engage to provide services on our behalf, for example cloud services providers and marketing services companies. These companies are based in the EU and North America.
    • Professional advisors including lawyers, accountants and insurers where necessary to enable them to provide their services to us.
    • Authorities who require reporting of processing activities in certain circumstances.

We may also share your personal data with third parties to whom we may choose to sell, transfer, or merge parts of our business or our assets. Alternatively, we may seek to acquire other businesses or merge with them. If a change happens to our business, then the new owners may use your personal data in the same way as set out in this privacy notice.

We require all third parties to respect the security of your personal data and to treat it in accordance with the law. We do not allow our third-party service providers to use your personal data for their own purposes and only permit them to process your personal data for specified purposes and in accordance with contractual obligations which ensure adequate protection for your personal data.

International transfers

We may share your personal data with entities within the Stack Overflow and into marketing systems used by the Stack Overflow. Given that we are an international organization with our headquarters in the U.S., this may involve transferring your personal data outside of the European Economic Area (EEA). Some of the third parties to whom we transfer your personal data are also based outside of the EEA, so their processing of your personal data will likewise involve a transfer outside the EEA. Where your personal data is transferred outside of the EEA we will use specific contracts approved by the European Commission giving your personal data the same protection as it has in the EU.

How do we protect your personal data?

We are committed to protecting your personal data. We put in place safeguards including appropriate technologies, policies, and contractual arrangements, so that the data we have about you is protected from unauthorized access and improper use, and we will not keep your personal data for longer than necessary.

How long will we use your personal data?

We will keep your personal data only for as long as is necessary for the purposes set out in this privacy notice and to fulfill our legal obligations. We will not keep more data than we need. While you remain a user of the Public Network, we will retain your data in order to keep providing services to you.

We are required to keep some basic information about our customers for a longer period in accordance with applicable tax laws. In some circumstances you can ask us to delete your data.

Your rights

Under certain circumstances, you have rights under data protection laws in relation to your personal data, including the right of access, the right to rectification, the right to erasure, the right to restrict processing, the right to data portability, and the right to object.

Under EU data protection laws you have a number of rights in relation to your personal data. These rights are not absolute – in some cases they will not apply to you, or to the particular use that we are making of your data. There are exceptions, for example if we have to process the data to comply with our own legal obligations; if that is the case we will let you know.

Your rights include:

  • Access to your personal information (by what is commonly known as a "data subject access request").
  • Require us to correct any mistakes in your information which we hold.
  • Require the deletion of personal information concerning you in certain situations.
  • Receive the personal information concerning you which you have provided to us, in a structured, commonly used and machine-readable format, and have the right to transmit that data to a third party in certain situations.
  • Object at any time to processing of personal information concerning you for direct marketing.
  • Object to Stack Overflow’s decisions being taken by automated means (including profiling) which produce legal effects concerning you.
  • Object in certain other situations to our continued processing of your personal information.
  • Otherwise restrict our processing of your personal information in certain circumstances.

For further information on each of these rights, including the circumstances in which they apply, See the guidance from the UK Information Commissioner’s Office (ICO) on individual rights under the General Data Protection Regulation.

You also have the right to take your concerns at any time to the Data Commissioner's Office (ICO, the UK supervisory authority for data protection issues (


The Stack Overflow Enterprise platform is not intended for children. We do not knowingly offer this service to anyone under the age of 16.


General Contact Information

Privacy Officer

  • Privacy Officer, 110 William Street, Floor 28, New York, NY 10038,, phone: 212-232-8280

EU Representative

  • Privacy Officer, Bentima House, 168-172 Old Street, London EC1V 9BP,, phone: +44 (0) 20 3349 1000