Translating EPUBs while preserving the display format unchanged can be achieved by locating the position of all the text and then translating and filling in the corresponding positions.

PDF.js is a JavaScript library used for rendering and interacting with PDF documents on a web page. Although primarily used for displaying PDF documents in a browser, PDF.js also provides APIs and functionalities for extracting text information from PDFs.

Looking for the best way to translate Word documents without breaking formatting? We reviewed the top 5 DOCX translation tools for 2026, from free quick-look options to professional workflows.