Chrome Extension That Finds Typos on Any Page
Highlight typos and grammar issues on any webpage with AI-powered detection.
Build a Chrome extension called "Typo Finder" that highlights typos and grammar issues on any webpage. The extension should: (1) provide a "Scan this page" button in the popup, (2) when clicked, extract all visible text from the current page, (3) send the text to OpenAI GPT-4 with a prompt asking it to identify spelling errors, grammar issues, and typos, returning a structured JSON list with the error text, the surrounding context, and the suggested correction, (4) inject a content script that highlights each error on the page (red underline) and shows the suggestion in a tooltip on hover, (5) provide a "next/previous error" navigation in the popup so the user can jump through errors. Permissions: storage, activeTab. Host permissions: <all_urls>, https://api.openai.com/*. Manifest V3.
What this extension does
Scans any webpage for typos and grammar issues using AI. Highlights problems on the page with red underlines and shows suggestions on hover. Useful for proofreading published content or fact-checking.
How it works
A content script extracts visible text from the page. The service worker sends the text to GPT-4 with a structured prompt asking for typo/grammar issues in JSON format. The content script then injects highlight elements at the matching positions in the DOM.
Permissions used: storage, activeTab
Host permissions: <all_urls>, https://api.openai.com/*
Who builds this
For writers proofreading their own published posts, editors reviewing content, content marketers checking landing pages, and anyone who wants to spot errors on any page they're reading.
How to build it in 3 minutes
- Sign in to PlugThis and open the chat input.
- Copy the prompt above and paste it into the chat.
- PlugThis generates the full Manifest V3 extension in 60-90 seconds.
- Download the zip, extract it, and load it via
chrome://extensionsdeveloper mode.
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Paste the prompt above into PlugThis and ship your extension in 3 minutes.