Hetzner

Key takeaways

Hetzner belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Hetzner to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Hetzner from memory before moving on to harder problems.

Reference excerpt

Hetzner Online GmbH is a company and data center operator based in Gunzenhausen, Bavaria, in Germany.

History Hetzner Online GmbH began operations in Germany in 1997 under the name Hetzner Online Services. Between 2000 and 2015, Hetzner Online in Germany operated under the legal status AG ("Aktiengesellschaft"). In 2015, it changed its legal status to GmbH. In addition, Hetzner Online expanded its chief executive team with Stephan Konvicka and Günther Müller at the beginning of 2019. The company is named after its founder Martin Hetzner. Hetzner Online owns and operates three data center parks in Nuremberg and Falkenstein (Germany), and Tuusula (Finland). It also rents colocation space in Ashburn, Virginia (United States), and Hillsboro, Oregon (United States). In 2024, Hetzner expanded its global footprint with a new data center in Singapore (Singapore). In addition, Hetzner Online is a co-investor in the Cinia C-Lion1 project, which connected Helsinki and Rostock, Germany together with a 1,100 km long submarine fiberglass cable. The cable provides a high-speed connection between Hetzner's German and Finnish data centers.

Services Hetzner Online provides dedicated hosting, shared web hosting, virtual private servers, managed servers, domain names, SSL certificates, storage boxes, and cloud. At the data center parks located in Nuremberg, Falkenstein and Tuusula/Finland, customers can also connect their hardware to Hetzner Online's infrastructure and network with the company's colocation services. The company operates a server auction site online where the chance to rent older dedicated servers (not purchase or colocate) are auctioned off in the form of a Dutch auction. According to W3Techs, Hetzner is used by 2.7% of all websites. Hetzner Online has a domain name registrar arrangement with ICANN (for registering domains under .com, .net and .org and others), DENIC (for .de), and nic.at (for .at).

Infrastructure Hetzner Online's datacenter projects are coordinated and implemented in-house with as little outsourcing as possible. Data center units served by multiple redundant uplinks, including 1300 Gbit/s to DE-CIX and fiber optic links to Nuremberg and Frankfurt. Colocation facilities are sited at all data center parks in Nuremberg, Falkenstein (Vogtland) in Germany, and Helsinki in Finland. In 2021, a datacenter in Ashburn, Virginia, was opened, marking Hetzner's first American server. By 2024, the company took a significant step by opening a datacenter in Singapore, marking Hetzner's first Singaporean server. In March 2025, Hetzner and MHB Montage launched HT Clean Energy, a solar initiative for data centers, marking a significant move toward reducing the carbon footprint of the company's data center operations.

Network

The backbone is set up in the form of a ring network between the datacenter locations Nuremberg and Falkenstein, as well as the most important Internet location, Frankfurt. All locations are connected to central exchange nodes such as DE-CIX, AMS-IX, DATA-IX, and V-IX via the company's own fiber optic network. All Hetzner's dedicated servers had a minimum 20 TB monthly cap for full speed on their servers with the option for an extra fee for full speed past that point. However, they have lifted the bandwidth cap on 1 Gbit/s connection speeds as of October 1, 2018. In 2025, Hetzner began upgrading its core network infrastructure using Nokia routing technology. The upgrade includes the deployment of 7750 SR-1x routers, which support 100G connections and are compatible with higher-capacity interconnects such as 400G and 800G.

Incidents

Hacking In June 2013, Hetzner Online suffered from a security breach where customer information was exposed to attackers who had compromised Hetzner Online's monitoring systems.

Russian complaints about Glavcom.ua In early August 2014, the Russian Federal Service for Supervision of Communications, Information Technology and Mass Media (Roskomnadzor) sent a demand to many news agencies prohibiting any mention of the demonstration that was being arranged in the Siberian city of Novosibirsk in support of the federalization of Siberia. A number of such messages were sent to Ukraine, which was in the midst of undeclared war with Russian paramilitaries in the Donetsk region. Since the Ukrainian online newspapers did not remove the article, Roskomnadzor sent letters to their internet providers demanding removal of the news item. Hetzner Online complied with the demands and sent a notice to glavcom.ua, saying "Please solve the problem and reply within the next 24 hours to avoid suspension. This is the final deadline." This story was widely reprinted in news sources. The Ukrainian Ministry of Foreign Affairs issued a statement expressing solidarity with glavcom.ua owners and journalists. Vassily Zvarych, vice-head of the Communications Department of the Foreign Ministry, gave a press conference saying that he was surprised by Hetzner Online's compliance with the Russian complaint. The German chapter of Reporters Without Borders also issued a statement condemning Roskomnadzor. The notices to suspend Glavcom.ua were issued by Hetzner Online August 6, 2014; on August 10 Hetzner Online issued apologies, denying that any censorship was planned and that their technical support made a mistake, which they regretted. However, by that time the story was widely published in German mass-media, and Glavcom.ua already migrated from Hetzner Online to another hosting provider.

no.spam.ee lawsuit In 2013, an Estonian anti-spam activist Tõnu Samuel posted a blog entry about an alleged spammer Silver Teede on his website no.spam.ee. In retaliation, Teede wrote a complaint to the blog's service provider, Hetzner Online, who decided to terminate services for the blog. In an ensuing court case, Estonian courts found the complaints to be baseless and awarded Samuel damages from Silver Teede for the loss of Samuel's servers.

Duplicate Ed25519 SSH keys From April 2015 to December 2015, many of the OS images used by Hetzner's installation program installimage had used duplicate Ed25519 SSH keys. This could potentially mean that an attacker could use a man-in-the-middle attack to compromise an SSH connection that was using Ed25519 keys. Hetzner sent an email to all affected customers with any potentially affected servers on information about the issue, and how to fix it.

… excerpt ends here. Continue reading the full article.

Worked examples

Example 1 — a first encounter with Hetzner

Start with the simplest possible case. Write down what Hetzner claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Hetzner before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Hetzner ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Hetzner

In research: Hetzner appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Hetzner in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Hetzner is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1997 establishments in Germany, Companies based in Bavaria, Data centers, so understanding it makes those chapters shorter.
In everyday life: Look for Hetzner outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

How to study Hetzner in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Hetzner means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Hetzner out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Hetzner in simple terms?

Hetzner Online GmbH is a company and data center operator based in Gunzenhausen, Bavaria, in Germany. History Hetzner Online GmbH began operations in Germany in 1997 under the name Hetzner Online Services.

Why does Hetzner matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Hetzner?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Hetzner.