AI extension for Firefox

People search for "Claude in Firefox" because most AI browser tools launch in Chrome first. In Copilotly you pick the model from a list, so Firefox gets Claude, GPT, Gemini, DeepSeek, Grok and Mistral in the same sidebar. Which models are available each day depends on your plan.

Firefox also has its own built-in AI features, which change between releases. Copilotly is a separate add-on with its own account and models.

• Chat with the current page, a YouTube video, or a PDF, Word, Excel or CSV file. Chat with PDF.
• Select text on any site to rewrite it, compare the changes and undo. Rewrite anywhere.
• Translate a whole page and read it bilingually. Page translation.
• Search the web with cited sources, or run deep research. Web search.

This is where Firefox differs. Per MDN's browser compatibility data, Firefox supports the SpeechRecognition API from version 160. On older Firefox versions the browser does not provide speech recognition, so dictation in Copilotly may not be available there. Typing, rewriting, translation and the rest do not depend on it.

If dictation does not start, update Firefox first. More on dictation.

Free covers fast models plus daily limits on premium messages, searches, images and translations. Pro is $6.99/week, $19.99/month or $149.99/year, with a 7-day free trial for first-time subscribers. See free and pricing.

1. Pin the add-on. Use the Extensions button in the toolbar, then the gear next to Copilotly to pin it.
2. Check private browsing. Firefox add-ons do not run in private windows unless you allow it per add-on. Do that only if you want Copilotly there.
3. Try rewrite on a real draft. Select a paragraph in any text field, choose a tone and length, and look at the word-level diff before replacing.
4. Translate a page. Right-click, "Translate this page", and read bilingually.

Two settings change how well answers fit you. Custom instructions and memory let you tell the assistant who you are and how you like answers, so you stop repeating yourself (see memory and personalization). My Voice learns your writing style, so rewrites sound like you rather than like a generic assistant.

Firefox users often care about privacy. Copilotly offers incognito chats, and you can use your own API key, in which case requests on that key are not metered by us. Read the privacy policy before sending sensitive content to any AI model.

Open about:addons and confirm Copilotly is enabled. Firefox blocks add-ons on some internal and Mozilla-owned pages, so test on a normal site. If the sidebar does not respond to Alt+C, another add-on or a system shortcut may use it; Firefox lets you review add-on shortcuts under the gear menu in about:addons. Reload the tab after installing.

For dictation specifically, check your Firefox version (Help, About Firefox) and the microphone permission for the site. Everything else, including rewrite and page translation, works independently of speech recognition.

Same features, different store

Chat, rewrite on selection, page translation, file chat and web search work the same way. You install and update through Firefox Add-ons rather than the Chrome Web Store.

The one place Firefox differs

Speech recognition. Chrome-based browsers have had it for years; Firefox support in MDN's data starts at version 160, so dictation depends on your Firefox version. See dictation.

What about Firefox on Android?

We have not verified the extension there. The Android and iOS apps give you the chat features on a phone.

Where do the free limits apply?

Limits are per account, not per browser: the same daily allowances across the extension, web app and mobile. The free plan page lists them and pricing shows Pro.

Copilotly runs as a desktop extension in Chrome, Edge, Firefox, Brave and Opera. Arc and Vivaldi also install the Chrome Web Store build. Safari is the exception: no Safari build is published, so the Safari page covers what to use instead.

How was the dictation column checked?

Dictation uses the browser's built-in speech recognition, so it follows the browser, not Copilotly. We took the support data from MDN's SpeechRecognition page. MDN also notes that in browsers such as Chrome the audio goes to a web service for recognition, so it will not work offline. Brave is marked "not verified" because we have not tested it. Rewrite, translation and chat do not depend on speech recognition.

What about phones and tablets?

Desktop extensions do not run in mobile browsers in general. On a phone, use the iOS or Android app, which works on the free plan. Everything is listed on the download page.

Limits belong to your account, so they are the same in the extension, the web app and the mobile apps. Free covers fast models within a token allowance, plus these daily allowances:

What does Pro cost?

Pro is $6.99/week, $19.99/month or $149.99/year, with a 7-day free trial for first-time subscribers. Compare plans on the pricing page.

Do my own API keys count against these limits?

No. Requests on your own key are never metered by Copilotly; see bring your own key.

The same account works everywhere, but the surfaces are not identical.

Rows marked No for the web app and mobile reflect that those features act on the browser page you are viewing. If you rely on them, the extension in Chrome, Edge or Firefox is what you need. For the rest, see all features.

Which shortcuts and menus matter?

• Alt+C opens the sidebar widget.
• Select text to show the rewrite toolbar; Cmd/Ctrl+K opens its command menu.
• Right-click selected text for the context menu, or right-click a page and choose Translate this page.
• Undo and versions restore earlier wording after a rewrite.

How do I turn it off or remove it?

Open about:addons, find Copilotly and use its menu to disable or remove it. Disabling keeps your settings in place if you change your mind.

Where does my text go?

Content you ask about, including selected text, is sent to the AI model you choose, so avoid using it on anything you would not paste into an online service. Incognito chats are available in the product.

Ask the same prompt twice

Run a question in one model, switch the picker and run it again. A GPT answer and a Claude answer often differ in wording and sometimes in substance, so a second opinion is cheaper than finding the mistake later. Neither is right every time.

Match the model to the job

Use a fast model for quick lookups and small edits, and a premium model when a question needs careful reasoning. Free accounts get 10 premium-model messages a day, so spend them on the questions that matter. Our professional-work comparison is a good starting point.

Check what matters

For anything you will send, publish or act on, read the result and verify the facts and numbers against the original source. Turn on web search when you need cited sources, then open the citations.

Be specific about tone and length

The rewrite toolbar has tone and length pickers. "Friendlier, shorter" is a clearer instruction than a bare rewrite, and you can run it again with a different setting. See rewrite anywhere.

Read the word-level diff

The comparison shows exactly what changed against your original. Approve the parts you like, use undo for the rest, and check that names, dates and numbers are untouched.

Teach it your style

My Voice learns your writing style, and custom instructions and memory tell the assistant who you are and how you like answers. Both are covered in memory and personalization. For a one-off reword with no setup, the free paraphrasing tool works without an account.

Ask specific questions

"What does the author claim, and where is the evidence?" works better than "summarize". Ask for quotes or section names so you can check them against the page.

Work in steps on long pages

Ask for an outline first, then dig into one section. For documents, upload the PDF, Word, Excel or CSV file instead and use chat with PDF. On video pages, ask for a summary and follow up on the part you care about; see YouTube summaries.

Know what leaves the page

Only ask about pages you are comfortable sending to an AI model. Pages behind a login, such as banking or health portals, are better left alone.

Check your organisation's rules first

Many employers restrict browser extensions or AI tools. Ask your IT or security team before installing it on a work profile. This is general guidance, not legal or compliance advice.

Keep sensitive content out

Selected text and pages you ask about go to the model you choose. Do not use it on confidential client data, credentials or personal records unless your policy allows it. Incognito chats and your own API key give you more control, but they do not change what is sent for a request.

Personal profile, personal use

A separate browser profile for personal use keeps work and personal accounts apart. See pricing for plan details.