To translate selected text in a local HTML file with a Chrome extension, first open the extension's details page and enable Allow access to file URLs. Then reload the file:// page and select the natural-language text you need. This keeps the local HTML document open in place instead of copying each paragraph into another translation site.
Why local HTML needs a separate Chrome permission
Chrome treats file:// pages differently from ordinary https:// websites. Chrome's extension documentation states that when an extension needs to run on file URLs, the user must grant that access from the extension's details page.
This is a user-controlled permission. Installing an extension does not mean it can automatically browse arbitrary folders on your computer.
Enable file URL access step by step
- Open Chrome.
- Open Extensions → Manage Extensions, or right-click the extension icon and choose Manage Extension.
- Open the extension's details page.
- Enable Allow access to file URLs.
- Return to the local HTML tab.
- Reload the page so the extension can initialize under the new permission.
If nothing changes after enabling the setting, reloading the local page is an important step. Tabs that were already open before installation or a permission change may not have the content script active yet.
Open the HTML file itself, not the whole folder
A local HTML workflow typically looks like:
file:///C:/project/docs/index.html
file:///Users/name/project/report.htmlThe extension works with the accessible page content Chrome exposes on the HTML file you opened. Do not interpret file URL access as a claim that the extension scans directories or searches unrelated local documents.
Translate only the part that blocks your reading
Local HTML is often mixed content: generated documentation, code examples, interface labels, product names, paths, and ordinary prose. Translating the entire document may change more than you need.
Start with one sentence or phrase. Keep code, commands, URLs, file paths, and identifiers out of the selection unless they are actually part of the natural-language sentence you are trying to understand.
Use more context when a single word is ambiguous
One word can carry different meanings depending on the sentence. If an isolated-word translation feels wrong, select a short phrase around it or set the source language manually. The goal is not to force a dictionary-style answer from a word that has several possible meanings.
Where LingPeek fits a local HTML reading workflow
LingPeek supports user-authorized local HTML pages. After file URL access is enabled, selecting eligible foreign-language text can reveal the Translate Lens directly at the reading position. LingPeek uses Chrome's built-in translation capability rather than sending selected text to a RANURANU translation backend.
You can add LingPeek from the Chrome Web Store. The LingPeek guide includes the local HTML setup and source/target language controls.
Chrome may need to prepare a language resource
Chrome's Translator API is available from Chrome 138. Chrome manages the translation capability and may need to prepare or download the required language resource for a language pair. If translation does not appear immediately the first time you use a language, keep the page open, allow Chrome to finish preparing the resource, and retry.
Know the limits of a local HTML translation workflow
LingPeek v0.4.0 is focused on selected DOM text. It is not a PDF translator, OCR tool, image translator, subtitle translator, or full-page translation system. Canvas-rendered text, inaccessible frames, custom document editors, and other surfaces that do not expose normal selectable DOM text may not behave like an ordinary HTML paragraph.
Be careful with sensitive local documents
Even when a workflow is local-first, use the same caution you would apply to any browser extension that has access to page content. Avoid exposing passwords, authentication tokens, customer secrets, medical records, financial records, or other confidential material unless you have verified that the tool and the environment are appropriate for that data.
LingPeek's product-specific privacy policy explains what the current extension temporarily processes and what preferences it stores locally.
Local HTML translation checklist
- HTML file explicitly opened in Chrome?
- Allow access to file URLs enabled for the extension?
- Page reloaded after the permission change?
- Selection contains natural-language text rather than only code or a path?
- Source and target languages correct?
- Longer phrase selected if one word is ambiguous?
- Chrome given time to prepare the language resource if needed?
- Sensitive local content handled according to your own privacy requirements?
Reading a local HTML page and only a few phrases need translation?
LingPeek is built for selection translation at the reading position, including local HTML pages you explicitly authorize in Chrome.