CAT Tool
Computer-Assisted Translation software that helps human translators work faster by providing translation memory suggestions, glossary lookup, and a side-by-side segment editing interface.
Definition
A CAT tool (Computer-Assisted Translation tool) is a desktop or web application that streamlines the work of a human translator. It does not translate automatically — the human does the translating. Instead, the software provides a structured workspace: the source document is split into segments (sentences or paragraphs), displayed one at a time alongside the target language editing field.
As the translator works, the CAT tool checks the active segment against the translation memory (TM) and surfaces any matching or similar previously translated segments. It also queries the project glossary for approved term translations, shows terminology inline, and may offer machine translation as a draft that the human then edits.
The most widely used CAT tools are SDL Trados Studio, memoQ, and Phrase (formerly Memsource). All three use XLIFF and TMX as interoperability formats so TMs and translation packages can be shared between them. Freelance translators and large language service providers (LSPs) rely on these tools as the core of their daily workflow.
Key Concepts
- Segment-based editing: Documents are split into sentence-level segments. The translator confirms each segment independently, enabling progress tracking, QA checks per segment, and partial-document delivery.
- TM leverage: When many segments match previous translations, the translator has high leverage — less original work required. CAT tools calculate the leverage percentage upfront so projects can be costed accurately.
- MT integration: Most modern CAT tools can call a machine translation engine (Google, DeepL, or a custom model) to prefill target segments. The human then post-edits rather than translating from scratch, significantly increasing throughput.
CAT Tools vs Vernacia
Vernacia is not a CAT tool — it automates the full translation pass rather than assisting a human translator. For teams that need document translation quickly without a dedicated linguist, Vernacia handles upload, AI translation, and formatted output delivery end-to-end. For workflows that do require human review, Vernacia can act as the MT engine feeding into a CAT tool: export the translated XLIFF from Vernacia, import into SDL Trados or memoQ for human post-editing, then reassemble the final file.
Related Terms
Skip the CAT tool for routine business documents — let Vernacia handle it end-to-end.
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