"I'm working on a Firefox extension that analyzes web page structure - somewhat similar in functionality to what SEO tools like RankingsFactor or SEO Minion do. However, I'm facing a permission issue when trying to access page content using the tabs and activeTab permissions. The same code works fine in Chrome but fails in Firefox with a "Permission denied" error when reading DOM elements."
"Here's a simplified version of my code: browser.tabs.executeScript({ code: 'document.body.innerText' }).then(result => { console.log(result); }).catch(err => console.error(err)); I've already added the following to my manifest.json: "permissions": ["tabs", "activeTab", "scripting"], "host_permissions": ["<all_urls>"] Is there any Firefox-specific restriction I should be aware of when accessing content scripts? Do I need an additional permission or event listener for this to work on all domains?"
Firefox requires explicit host access for content scripts and can deny DOM access when the extension lacks permissions or is running on a protected internal page. The activeTab permission grants temporary access only after a user gesture and may not apply universally across all domains. The tabs.executeScript call can fail in Firefox if the extension is not granted host permissions or if the page is in reader view, about:, view-source, or other privileged contexts. Manifest edits require reloading or reinstalling the extension to take effect. Using scripting.executeScript with proper host_permissions and checking for protected pages resolves most Permission denied errors.
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