Translate Web Pages (TWP): a Firefox extension that translates the page you are already on

What TWP replaces in the browsing flow

The usual way to read a foreign-language page is to copy the URL into a translation service and read the result in a second tab. That breaks the page you were on: its session, its scroll position and any logged-in state stay behind in the original tab. TWP takes the opposite route. The README describes the behaviour plainly: "Your current page is translated without having to open new tabs." The extension reads the text of the page you are already viewing, sends it for translation, and writes the translated text back into the same document.

The audience follows from that. It is for people who land on pages in a language they do not read often enough to learn it, and who want to keep the page itself intact. The README also covers the permission question directly: the extension needs access to all sites because "to translate any website it is necessary to access and modify the text of the web pages." That is not a design flourish, it is the cost of doing translation in place. If you are not comfortable granting a translation extension read and write access to every page you open, this model is not for you, regardless of engine choice.

How the translation engine is selected and where the text goes

TWP is a client of external translation services rather than a translator itself. The README's FAQ answers "How are the pages translated?" with: "The pages are translated using the Google or Yandex translation engine (you choose)." The project description adds Bing to that list. Engine selection is exposed in the UI: the README says "To change the translation engine just touch the Google Translate icon." So the engine is a per-user setting surfaced through the Google Translate icon, not a build-time choice.

The consequence is a hard privacy boundary. The README's privacy answer states that the extension does not collect information, then adds the qualifier that matters: "However, to translate, the contents of the web pages will be sent to Google or Yandex servers." In other words, the extension keeps no data, but the page text leaves your machine. For a public news article that is unremarkable. For an internal dashboard, a webmail session or a page behind a corporate login, it means the content of that page is handed to a third party. TWP does not offer an offline or self-hosted translation path, so there is no configuration that avoids this.

The repository is a WebExtension written in JavaScript, with a gulp build and a webpack step for the polyfill. The package.json declares core-js as the only runtime dependency and pins the browserslist to "firefox 63" and "chrome 70", which tells you the code is compiled down for older engines rather than relying on current browser APIs. The licence is MPL-2.0, a file-level copyleft: modifications to files already under the licence must stay under it, and the licence does not extend to unrelated files you add. That matters if you intend to fork and redistribute, and it is worth reading the LICENSE file rather than taking this summary as legal advice.

Installing TWP on Firefox and translating a first page

The README gives one install path for desktop Firefox: download from Mozilla Addons. There is no npm install and no self-hosted server. Open the addons.mozilla.org listing and add the extension to Firefox, then confirm the TWP icon appears in the toolbar.

Firefox for Android takes a different route, and the README is specific about the steps. First install Firefox v120 or newer. Then open the extension manager, scroll down and click Find more add-ons, search for TWP on the add-ons website, and install the TWP - Translate For Mobile extension. Note the name: on Android the listing is not the same one as desktop, and the README states the v120+ requirement explicitly.

Once installed, the first real use is a single click. Load a page in a language you do not read, then click the TWP toolbar icon to translate the current tab in place. The README describes two further controls: you can change the translation language, and you can select automatic translation so pages are translated without a click. The engine is switched from the Google Translate icon in the interface.

For anyone building from source rather than installing a release, the README points to build-instructions.md and package.json defines the entry points. The build runs through gulp:

npm run build

There is also a signing variant, `npm run build:sign`, and a sourcemap variant, `npm run build:local-sourcemaps`. The polyfill is built separately with `npm run polyfill`, which runs webpack over polyfill.js and writes to src/lib. The README does not document a rollback procedure for a release, and the repository's dist/chromium directory holds the README's registry cleanup files.

Pages TWP cannot touch, and the Chrome problem

Two limitations are stated outright in the README, and both are the kind that surprise people after install rather than before.

The first is site coverage. "Some pages like support.mozilla.org and addons.mozilla.org will not be translated. For security reasons, the browser blocks extensions from accessing these sites." This is browser policy, not a TWP bug, and it generalises: any origin the browser shields from extension content scripts stays untranslated. If your workflow depends on translating a vendor's own support or add-on pages, TWP will silently do nothing there.

The second is browser support. The README is unambiguous: for Chrome, Edge and Brave, "The extension will be officially released for these browsers in the future." There is no published date. Worse, the README warns that if you previously installed the extension in those browsers through a registry modification, you should undo those changes, and it links two .reg files for that purpose, twp-registry-uninstall-self.reg and twp-registry-uninstall-all. That history is worth knowing before you follow an old tutorial: side-loading TWP into Chromium browsers via the registry is a path the project is now telling people to back out of. The recent release tags do include Chrome MV3 builds, so work on Chromium is happening, but the README does not promise a store listing.

There is also a privacy limitation that the README states rather than solves. The extension itself collects nothing, but the page text is sent to Google or Yandex. Anyone handling material that must not leave the network should treat TWP as the wrong tool, not a tool to configure carefully.

TWP against browser-native translation

The obvious alternative is the translation feature built into the browser, and the difference is architectural rather than cosmetic. Browser-native translation is tied to the vendor's own engine and its own rollout schedule, and it is not something you choose per page from a list of providers. TWP is a client that lets you pick between Google, Bing and Yandex and switch provider from the toolbar icon, which is useful when one engine handles a particular language pair better than another, or when one is unreachable from your network.

The second difference is the same one that makes TWP attractive in the first place: in-place translation of the current tab, with the option to auto-translate, rather than a separate translated view. If your browser's built-in translation already covers your languages and you do not care which engine is used, TWP adds a permission and an external data flow for a capability you already have. If you do care about engine choice, or you are on Firefox where the built-in feature may not cover your languages, TWP is the more configurable option.

A third, less obvious alternative is doing nothing in the browser and translating the document elsewhere. That is the right answer for PDFs, which the README does not mention at all: TWP is described as operating on web pages. If your task is translating a downloaded document, this extension is not the tool.

Maintenance cost and what the licence means for forks

The repository is not archived, and the last push was on 2026-10-29. Release tags in the 10.2.x line appear in August 2026, including v10.2.5.0 tagged as a Chrome MV3 build. For a user, that means the project is still receiving commits and packaged releases; it does not mean any particular bug you hit will be fixed on a schedule, because the README lists no support commitment.

Upgrade cost is low on the user side. Firefox extensions update from the addons listing, and the README gives no manual upgrade steps. On Android, the README's instruction to install TWP - Translate For Mobile implies a separate listing to keep current. The one upgrade hazard the README does document is the reverse: if you are on Chrome, Edge or Brave via a registry modification, the project asks you to undo it, and the two .reg files in dist/chromium exist for that. That is a cleanup task, not an upgrade.

For anyone forking, the build chain is the cost centre. The package.json pulls in gulp 5, gulp-babel, gulp-zip, webpack 5 and webpack-cli 7, plus crx3 for Chromium packaging and node-file-dialog, with core-js as the only runtime dependency. The browserslist targets firefox 63 and chrome 70, so the source is transpiled for engines far older than current releases, which is a deliberate compatibility trade rather than a modern-baseline build. The MPL-2.0 licence applies at file level: files already covered stay covered when you modify and redistribute them. The PRIVACY file and the linked Mozilla privacy policy are the places to read for data handling; the README's own statement is that no information is collected while page contents go to Google or Yandex.

Editorial conclusion

Adopt TWP if you browse on Firefox desktop or Firefox for Android and want in-place translation with a choice of engine, accepting that page text is sent to Google, Bing or Yandex. Do not adopt it if you need Chrome, Edge or Brave today: the README says the extension will be officially released for those browsers in the future, and if you installed it there through a registry modification it tells you to undo those changes. Before installing, verify the current release on the Mozilla Addons listing, and on Android check that Firefox is v120 or newer, since the README states that requirement for the TWP - Translate For Mobile add-on.

Frequently asked questions

Official sources

1. FilipePS/Traduzir-paginas-web on GitHub
2. License: MPL-2.0
3. Project website
4. README
5. Releases