What is a CAT tool?

The “CAT” in CAT tool stands for “Computer Aided Translation” or “Computer Assisted Translation” but, as you might already know, it doesn’t mean that a computer is actually completing the translation for you. CAT tools are different than “machine translation”  – they assist a human translator in doing their work more quickly and in managing their translation projects. CAT tools typically contain a translation memory, which stores previous source and target translations for easy reference while working. Term bases are also an integral part of translation tools, giving translators the ability to develop their own bilingual glossaries in their subject areas.

CAT tools can include a wide range of different features. Some can work with different types of documents, such as Powerpoint presentations, without needing to convert the text to a different file format. Some provide access to online terminology databases or help the translator to better manage translation memories. Some are software-based and some operate entirely in the cloud.

There is an incredible variety of CAT tools available on the market. As a translator, you could go crazy trying to find the perfect CAT tool, but really there is no single perfect CAT tool. Your choice will depend on a number of factors. What CAT tools do the agencies you work with want you to use? What is your budget? How technically minded are you? Which features will you really use?

We’ve created a comprehensive list of the many CAT tools available on the market right now, including a run-down of their features. If you’re thinking to yourself “How will I ever find my perfect CAT tool,”  just read on:

The big players

These are a few of the most popular and well-known CAT tools. Many agencies will expect you to have a working knowledge of and/or license for at least one of these:

SDL Trados Studio

Trados might be the biggest of all the big players in the CAT tool market. It is a complete translation software solution for translating, managing terminology, editing, and running LQA. Various versions are available for freelance translators with yearly or perpetual licenses.


memoQ is another major CAT tool, although not as well-known as Trados. It offers many or most of the same features, and has some useful extras such as the translation preview pane that allows you to see the segment you are translating in-context. memoQ can accept Trados and other packages, meaning that translators can usually work together with agencies who use other translation software. memoQ has a free version that is suitable for personal use or small projects, and the pro version is available with a perpetual license.

Wordfast (Classic & Pro)

Wordfast Classic is a macro that runs within Microsoft Word, temporarily turning any document into a bilingual document. Wordfast can work with any format that Microsoft Word can handle, including plain text files, Word documents (DOC/DOCX), PowerPoint (PPT/PPTX), Microsoft Excel(XLS/XLSX), Rich Text Format (RTF), tagged RTF and HTML.

Wordfast Pro is a more complete solution that includes terminology management and translation memory management. It also includes more project management features and supports additional file formats such as  Java, InDesign (INX/IDML), InCopy (INC), FrameMaker (MIF), Quark (TAG), Xliff (XLF/XLIFF), SDL Trados (SDLXLIFF/TTX) and editable PDF.

Both versions of Wordfast are available with a perpetual license, and even offer a discount to users in developing economies.

Déjà Vu

Déjà Vu is another popular CAT tool that offers a full host of terminology management and translation memory features. It prides itself on an especially customizable and user-friendly interface and can handle a wide variety of file formats, including Trados and memoQ. It is available with a perpetual license.


Across is another fully-featured CAT tool that ticks all the boxes. It offers a complete translation environment including translation memory, terminology management, quality assurance and project management. The basic edition is available only for online use at no cost, while the premium version can be used stand-alone and charges a monthly fee. Across also features an online job portal called crossMarket.

Free CAT tools

CafeTran Espresso

CafeTran Espresso is a unique translation tool that can be used on Windows, Mac, or Linux. It handles most major file formats and is compatible with other major translation programs. It is available for free until translation memories or glossaries reach a maximum size.


OmegaT might be the most popular free CAT tool out there. It is an open-source program that offers a full range of features and runs on Windows, Mac and Linux. It is also compatible with Trados files.


Similis is a less-known CAT tool that provides users with a translation memory and supports HTML,XML, PDF,MS Word, OpenOffice, and Trados files.

Wordfast Anywhere

Wordfast Anywhere is another fully-featured, yet free, CAT tool. It must be used online, but allows users to create private TMs, TBs, etc. It also offers connection to public translation databases.


MateCat is a free online CAT tool that offers users a variety of features. It is particularly focused on giving users access to machine translation databases to improve their working speed. It also serves as an outsourcing platform for LSPs.


SmartCAT is a CAT tool that also provides a platform for translators and clients to find each other. It even provides ratings systems and handles the payments. It charges a commission on top of the rates set by the freelancers.


Virtaal is a simple, free translation tool tool written in the Python programming language. It is developed and maintained by Translate.org.za. It includes translation management tools and access to machine translation.


Pootle is  a free translation management tool and interface. Unlike most CAT tools, it is specifically designed for translating apps rather than documents.


Lokalize is a CAT tool focused on productivity and quality assurance. It is designed especially for software translation but also integrates external conversion tools for document translation.


GlobalSight is an open-source translation management system that automates, streamlines, and manages the localization process. It can be used by project managers, translators, and editors.


gtranslator is a specialized translation tool for translating software that uses the gettext system. It is is programmed for use on the GNOME desktop environment.


Other paid CAT tools

XTM Cloud

XTM Cloud can process most common file formats by converting them to XML before adding them to the translation memory, then reformatting the file once the translation is complete. XTM is available as two different licensing models - a traditional software licence called XTM Suite or as a SaaS solution via an online subscription called XTM Cloud.


Phrase helps businesses scale their localization processes through smart automation on a single platform so that translators can create high-quality translations, developers eliminate manual tasks, and project managers cut localization costs.

Star Transit

Transit is unique in that it retains the source document's overall structure even in the translation memory. This means there are no segments stored out of context. Any You can display and check the original context of a reference segment at any time. In doing so, you ensure an easy-to-understand translation that is suitable for its purpose. This also avoids a collection of context-free text segments. It is available as a monthly or yearly subscription.


Poedit is a translation tool designed specifically for translating and localizing interfaces. It extracts strings from the source code and provides a variety of translation and quality-control tools. It can even be fully integrated to work on Wordpress. It is available for perpetual license.


MetaTexis is another translation tool available for free or in various paid versions with different features. It prides itself on it’s comparatively low price point, even for the most advanced version.


Pairaphrase is a web-based translation system that combines machine and human translation. It features a unique voice-over translation capability. A free version with very limited features is available. Various paid subscriptions are available for a monthly fee.


We use only translators carefully selected to match the subject matter and content of your project. Our translations meet and exceed international quality standards. Upon request, we will provide you with a statement which certifies the accuracy of our translations.