Firefox Nightly lets you access Microsoft Copilot from the sidebar
Copilot supports generating text, code, and images, as well as analyzing uploads like documents or pictures.
Mozilla is quietly testing a new feature in Firefox Nightly that integrates Microsoft Copilot directly into the browser’s sidebar, joining existing options like ChatGPT, Anthropic Claude, Google Gemini, and Le Chat Mistral.
The discovery, made by Windows Report’s Venkat, shows that Mozilla has been preparing this move for nearly a year, marking a significant step in its approach to AI tools inside Firefox.
When enabled, Copilot appears in the sidebar with a brief overview of its capabilities. Users can access it without an account, though functionality is limited.
Free use comes with daily limits, no personalization, no chat sync, shorter responses, and restricted access to advanced features.
Premium subscribers, however, gain extended options, including richer interactions and longer responses. Copilot supports generating text, code, and images, as well as analyzing uploads like documents or pictures. Voice interaction is also supported.
The feature offers three response modes: Quick Response, which replies within a few seconds for casual chats, Think Deeper, which takes more time to process complex prompts, and Smart, powered by GPT-5, which dynamically adjusts between quick or deep reasoning.
In addition, Copilot integrates with page actions in Firefox. Right-clicking on text, a web page, or even a browser tab brings up summarization options, while its dedicated sidebar shortcut makes it easy to launch a conversation or generate content.
Importantly, Mozilla has made it possible to fully disable Copilot and other AI features. The AI integrations don’t run in the background and act more as shortcuts to external AI services.
Users who prefer a clean browsing experience can remove Copilot from the sidebar or right-click menu, or turn off all AI tools entirely through Firefox’s advanced about:config preferences.
Options such as browser.ml.enable, browser.ml.chat.enabled, and related settings can be set to false, effectively removing AI integrations.
For those who want to test Copilot, the feature is currently limited to Firefox Nightly, which can be downloaded directly from Mozilla’s development builds. While some users may welcome the convenience of AI tools built into the browser, others remain skeptical, preferring alternatives like Vivaldi, which recently confirmed it will not integrate AI features at all.
