Patent Translation

April 21, 2022 |

Patent TranslationFor patent translation, your Language Service Provider should provide full and accurate translations at a competitive price and be able to:

  • Translate filings to virtually any language
  • Reduce litigation risks with subject specialists experienced in patent work
  • Thoroughly review patent literature filed on a global basis

Patent translators can spend hours looking for the right translation of an obscure or illegible character, word, or technical term. Because many foreign patents include English summaries and nearly identical patents can sometime be located in English, the correct answer can often be found and verified quickly and accurately on the Internet. The key is knowing where to look. This article will introduce several important resources for translating patents into English.

Every year, thousands of patents are translated from scores of languages into English. In terms of the number of patents, Japanese leads by a wide margin, followed by German and, at a distant third, French.


Whether you translate patents from Japanese, German, French, or another language, arguably the most important resource is the search page of the European Patent Office (EPO). This site contains a wealth of technical terms and life-saving context that can answer most questions. The EPO site is home to a database containing some 30 million patent applications from many countries (including Japan), not only in English but also in Japanese, German, French, and many other languages.

All unexamined Japanese (Kokai) patent applications cataloged on the EPO site include English summaries and thus can be found by running a search in English on the EPO search page. If you translate from languages other than Japanese or German, you can use the EPO website to find translations of certain technical terms provided by other people – often patent agents in their respective countries – in both English and in the languages of a great number of Patent Cooperation Treaty (PCT) member countries. A search for a technical term in English may also display translations of patents containing this term written in languages such as Czech, Polish, or Chinese, provided that the patents filed in those languages include English summaries.

Currently, only foreign patents that have been translated into one of the European national languages and filed in their respective countries can be found in this manner. However, with the accession of more countries to the European Union, this situation is changing rapidly, and English has become a lingua franca for the members of the European Union (25 countries as of late 2006). Thus, it can be expected that more patents originally filed in one of many “languages of limited diffusion” will soon include accurate English summaries.

As American, German, and Japanese companies aggressively enforce their patents right in foreign countries, they are translating their patents into many national languages in order to file them in different countries. Because these patents are available in English, translators of patents in foreign languages can compare terms in a Czech translation, for example, to those in the original English text.

The EPO website does have several disadvantages. First, the search results display only the first 500 patents that contain the search terms, though this is usually more than enough. On the sites of both the EPO and the German Patent Office (GPO), if a search combines two or more terms, patents containing either term will be returned (up to 500), complicating the task. The Japanese gives you a choice to select [and] [or] for various combinations of terms. However, the results can still be unpredictable as is often the case with searches on Internet.

Second, the EPO website often cannot find foreign patents that do not have English summaries, even if you have the correct patent number. A workaround is to search the JPO or GPO site in the language in question. You can also go to directly to the website of the patent office in the country where the patent was issued since most of them offer an interface in English.

The shortcoming of the EPO search function for patent translators is that search can be performed only in English, with some exceptions, such as Recherche avancée (advanced search) which can be searched both in French and in English. The JPO and GPO sites, on the other hand, offer the ability to search in their national languages or in English. On the GPO website, only a limited number of patents originally filed in German include English summaries. The text of the English summaries is usually in HTML format, whereas the text in other languages is displayed in PDF format. Translators can save and print the English summary in Microsoft Word or another word processing program.

Patents originally published in Japanese, German, French, Czech or Chinese may have been previously translated and filed in another language in another country. This can help in defining search terms. For example, you could type in the name of the inventor or patent applicant (usually the name of the company) or context from a similar patent.

You may even discover that the patent in question has already been translated into English. For example, a patent may have been originally filed in Japanese in Japan or in French in Switzerland and then translated and filed in the United States or Europe in English. However, because patents are almost always modified to comply with the filing requirements of different countries, your client may request a full translation in order to ascertain exactly how the patent was changed. For example, a German patent may have been filed originally in German, but also in English as a European patent or PCT patent. The German text may be very similar to the English text, but there will be some differences between the two. For example, some embodiments or claims may be changed, omitted or added. You may be asked to translate only the claims, which are almost always revised, or the entire patent, in spite of the cost. For example, if the case is being litigated, since a minute terminological change or turn of phrase may affect the final result, a new certified translation may be required.

If you do not thoroughly research patents by comparing two versions of the same patent (which are not really the same), you will be at a distinct disadvantage compared to a translator who does. You can display the instructions on the EPO website in English, German, French, and many other European languages through interfaces in various national languages (see Table 1). However, you might also begin by searching the GPO website to find the relevant patent number or the names of inventors in this manner. You could then return to the EPO site armed with the patent number or the inventor’s name, which may have been invisible when the search was conducted in English. You may find an English summary, a similar patent, or a patent filed by the same inventor or the same applicant that includes a comprehensive English summary or is written entirely in English.

One advantage of the EPO website is that it provides the “family” of the patent – that is to say, equivalent (similar) patents that have been filed in other languages. This will allow you to find the English text of a foreign patent if one exists, or the foreign text of a U.S. patent if the same patent application has been filed in another language in other countries.


Experienced Japanese patent translators will be familiar with the Japanese search pages of the JPO website. However, even some US patent lawyers are unaware of the English search pages available on the same site which offers an interface in English. The Japanese portal offers a more comprehensive collection of Japanese patents than the EPO site, including examined (Kokoku) Japanese patents, as well as examined and unexamined Japanese utility models and granted patents.

You must specify PDF format in order to return a legible copy of the Japanese text (the default resolution loads faster, but at 90 dpi, it is very hard to read). The Japanese part of the site can be searched for terms in Japanese but not in English. Likewise, the English part of the site can be searched only for terms in English. However, Japanese text can be displayed in HTML or PDF format and then copied for use in search of patents on the Japanese part of the site. Or you could type terms in Japanese, display Japanese patents containing these terms, and then locate English summaries of these patents.

Often, it is helpful to use the title of the patent and the terms provided in the English summary in the translation because clients will also be using them. However, the English summaries are typically written by native Japanese speakers, so a compromise or a fresh title may be needed. Often, one can understand the English text of these summaries only after comparing them to the Japanese original. This is attributable to the fact that most of these summaries are written not be professional translators, but rather by Japanese subject-matter experts.

Despite these drawbacks, the Japanese make a strenuous effort and spend a great deal of money to provide access to technical information to specialists who do not speak their beautiful but complex language. The GPO website (DepatisNet), by comparison, provides an English interface for navigation but relatively few English summaries of German patents. The JPO site contains English summaries for all unexamined patent application, and machine translations of all unexamined patent applications filed after 1994 which can be easily accessed by clicking on the button DETAIL on the JPO site after the application, which is especially helpful for those who do not read Japanese. Although English summaries are not available on the JPO site for examined applications and granted patents, you can identify the unexamined version in order to find an English summary, or download a full machine translation of an examined version in a couple of minutes.

The machine translation feature of the JPO site is a reflection of Japan’s interest in overcoming the “Japanese language problem”. Relatively few foreigners can read and write Japanese, and relatively few Japanese are really fluent in English or other languages. Therefore, the machine translation function in Japanese search engines is probably used more frequently in Japan than in any other country. Although the machine translations do not provide a “real” translation, they will give the reader the gist of the original text. The availability of the Google interface in many languages, including Japanese, is also very helpful. For example, one can often fined a combination of obscure Japanese, German, or Czech medical terms by entering the terms in one of these languages and including an  English or Latin word using Google’s language tools function.


The German Patent Office (GPO) website, DepatisNet, has a more complete coverage of patents and utility models in German than the EPO website. Both German and English interfaces are supported, and both can be searched using English or German terms. A major advantage of the GPO search page is that a search for terms can be run in both English and German, whereas the EPO site offers only English searching. Like the EPO website, you can specify whether to search for an item within the title of a patent, within the full text, or both. Up to five items can be specified, including the number of the patent publication, the name of the inventor, and the name of the patent applicant. You can search for patent titles and words in the full text of patents. You can also transcribe umlauts using two vowels, a sharp S using “ss” and so on, which is a handy feature for those who do not type in German every day. For example, you could type “Extrusionbeschichten von Polymerfolien” to search for patents containing the terms and context needed in German, which will often be displayed alongside PCT patents in English or French. Or you could type “extrusion coating of polymer films” to find a patent in German, as on the EPO website. You can sometimes find a translation of the same patent from German into English or vice versa by searching for the name of the inventor or of the patent applicant and then researching the technical terms and relevant context that are returned.

If you translate from French, you can also double-check the correct terms in French, as Canadian patents are typically listed for the same subject. All Canadian patents include a French summary, and Canada produces quite a number of patents in many technical fields. In fact, according to a Washington Post article on July 23, 2010, Canada is now the global leader in high education among young adults, with 55.8 percent of that population holding an associate’s degree or better as of 2007, the year of the latest international ranking. In the United States, 40.4 percent of young adults hold postsecondary credentials. Not so long ago, US was at number 1 in the world in the share of adults with college degrees, now we are at number 12 and it is an open question whether we will be able to get our mojo back in America.

The French Patent Office used to require paid registration for access. However, patents in French can be also researched using the Recherche avancée function on the EPO website or the World Intellectual Property. The World Intellectual Property Organization’s website can also be used to confirm English translations of French terms.

You can use the GPO website to look for patents in languages other than German, including Japanese patents, which are displayed in PDF format. Like the EPO site, the GPO site displays patents in Japanese and in French, as well as a limited number of patents in other languages if English summaries are available or if they are linked to the database. Thus, the GPO site allows you to specify many countries of origin, as well as the type of application (unexamined patent applications and utility models, which are used in some European countries and in Japan).

The GPO website is linked to databases containing patents in Japanese and other languages, making it especially helpful. For example, when new texts are being loaded onto the JPO site, access may not available for an extended period of time (often over the weekend when patent lawyers like to keep us poor patent translators cooped up in our home offices). The websites of different patent offices often use different conventions for identifying patents, which presumably will continue to change – for example, the number of digits that must be typed into the search field may require “leading zeroes”, or you may need a dash after the first two digits for older patents on the JPO website, none of which may be reflected in the format of patent number that you were just e-mailed from a law firm. If you cannot display the patent that you are looking for on the JPO website, you may have a better luck with the EPO or GPO site.


The Intellectual Property Digital Library (PatentScope) provides free access to the data collection hosted by the World Intellectual Property Organization (WIPO) in Geneva. The PCT Electronic Gazette contains data relating to PCT international patent applications filed after January 1997. The text of these patent applications can be also downloaded from the EPO or GPO website in English, French, German, or Japanese as PCT applications may be published in any of these languages. However, the chief advantage of the WIPO site is that you can search not only in English, but also in German, French, Spanish and now also in Japanese. You can type terms in Japanese, German or French to display English, French or Japanese summaries of patent applications containing these terms or the text of the PCT application in the original language. The newly revised site also offers instantaneous automatic machine translations (through Google translate) of summaries to English, French, German, Japanese, Chinese, Korean, Portuguese, Russian, and Arabic. You can also search using keywords in all the 9 languages mentioned above to display an English summary which should contain a translation of this word into English. However, the word will sometime not be listed, presumably when it is contained only in the text of the description or of the claims.

This site provides the fastest way to display a summary in German, French, or Japanese next to an English summary because all PCT patents come with English summaries. One disadvantage is that unlike on the Japanese Patent Office website, the small Japanese font on the WIPO site is a little hard to read. If you display the HTML version, the desired term should be highlighted in Japanese, German, French or English, depending on the language of the application. If you are reasonably certain that a term can be found in a PCT patent, this site is preferable to the GPO site because it is much faster to navigate and to switch between German and English (or at least it used to be). Even if you do not input the correct special character, you will still get results sometime, though it is unclear why this is so. However, to search quickly and accurately, a term with an umlaut, a sharp S, or French accents can be copied from another patent and pasted into this database for easier searching.

If the original language is not based on the Latin alphabet (e.g. Japanese), the application will display only as a PDF file. This makes searching complicated but not impossible if you have the full version of Adobe Acrobat. This website covers only PCT patents issued since 1997, so its database is smaller than that of the EPO website. However, if the technology is fairly recent, the chances are good that the relevant term and a number of English translations will be found. The WIPO website thus can be used as a sort of a French-to English and English-to-French (or German-to-English or English-to-French) dictionary. This site is a very useful database of terms for translators of German and French patents into English.


The patent offices of most countries can be easily found on the Web by running a search in Google. Some offices may require registration or payment before they will allow you to search.

The URLs of patent offices often change when owners add new functionality. For example, both the JPO and the French Patent Office have changed their URLs in the last few years.

Whatever one may think of the Microsoft Windows operating system, it is now easy to use English, Japanese, German, and Czech, for example, on the same computer running a Unicode-based version of Windows, from Windows XP to Windows 7. This means that the same computer can run Internet searches quickly on many different websites, as well as on the Google interfaces that are available in different languages.

The national offices of countries that cooperate with the EPO provide interfaces in many languages, allowing easy access to the EPO server and the databases of those offices. The EPO database can sometime (depending on the language) also be used to find the correct translation of technical terms in a number of languages.

Table 1 lists the countries that cooperate with the EPO and the languages supported by their sites. The URLs will take you to the EPO search page with interfaces in the respective languages, and you can click your way to the main page of national patent offices from this search page as well. For example, you can run a search in Czech after clicking a few links. You can then display a patent filed by a major US, German, or French company in a Czech translation in the Czech Republic in order to compare Czech translations of technical terms to English technical terms.

Going through the interface in a national language sometime allows you to search for terms in languages other than English or German. For example, you could type a French technical term in the Czech interface of the EOP website in order to display French patents from the French Patent Office. This may also work for interfaces in other languages. One can hope that at some point in the future, the European Union will make it possible for translators to quickly access the text of patent in languages other than English through the website of each country.

Table 1 – Countries Cooperating with the European Patent Office 

CountryURLLanguage Support
Belgiumhttp://be.espacenet.comFrench, Dutch
Czech Republic
Liechtensteinhttp://li.espacenet.comFrench, German, Italian
Switzerlandhttp://ch.espacenet.comFrench, German, Italian
United Kingdomhttp://gb.espacenet.comEnglish

Patent translators who are aware of important Internet resources can also locate patents for clients who may not know how to find the text of foreign patents online. For example, We sometimes get calls from chemists, librarians, paralegals, inventors, and translator agency coordinators who may have only the patent number or an English summary of a Japanese or German patent and do not know how to obtain a copy of the foreign-language text. Once we have the correct number or other information describing the patent in question, we can quickly download the patent from the JPO, EPO, GPO or WIPO website, create a PDF file and send it to the new prospective client with a cost and turnaround time estimate. Thanks to the Internet, relatively inexpensive high-speed connections and wireless networks, multilingual patent translators can even provide a limited patent search service in a foreign language.

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