Which web translation extension should you choose?

First, decide which kind of "web translation" you need

Before choosing a web translation tool, identify which problem you need to solve: Translating a passage once in a while (just paste it into an online translator), Understanding a whole page quickly (the browser's built-in translation is enough), Close reading against the original (which needs a bilingual extension). This article is about the last case: translations inserted below the original, so the page reads like a bilingual book. Immersive Translate and its web version do the same thing.

What the two extensions are

Immersive Translate: one of the pioneers of this category, covering web pages, PDFs, e-books, video subtitles and more across platforms and formats, with a wide choice of engines and AI models, free basics and a subscription for advanced features.

TopCopilot AI Translation Assistant: the browser translation extension from TopCopilot, built around "full-page bilingual reading with four switchable engines" — Bing, Google, built-in browser AI (free) and LLM models (credits) — plus selected-text translation, a word dictionary and English grammar analysis, sharing one account and credits with the TopCopilot web app and the Word / Excel / WPS add-ins.

Comparison across five dimensions

Who should choose Immersive Translate

• You need to translate PDFs, papers, e-books, video subtitles and other content beyond web pages;
• You work across several devices and browsers and are willing to pay for advanced AI engines;
• You rely on its mature custom-styling and keyboard-shortcut ecosystem.

Who should choose TopCopilot AI Translation Assistant

• You mainly read English pages in Chrome / Edge and want free Bing / Google / built-in browser AI engines;
• When reading foreign-language articles, papers and technical documents you want word dictionary cards and English grammar analysis to support close reading;
• You already use the TopCopilot Word / Excel / WPS add-ins or the web app —same account and credits so documents and web pages share one system;
• You want "main content only, skipping navigation and ads" so the page stays clean after translation.

Summary

Both are bilingual web translation extensions that put translations below the original; the real difference is the ecosystem. Immersive Translate wins on platforms, formats and engine count; TopCopilot wins on its free engine mix, close-reading tools and one account for Office documents. If your work is "read English pages in the browser + translate documents in Office", the latter connects both sides with one account; if you often read foreign content on a phone or e-reader, the former fits better. You can also install both and switch per page.