Privacy of AI chat extensions: what to check before you install

An extension that runs on chatgpt.com or claude.ai can technically read everything you see on the page: questions, answers, uploaded files. For a chat organizer that's unavoidable — to file chats into folders and search their text, it has to read them. The real question is what it does with what it reads.

Why this isn't paranoia

In December 2025, researchers at Koi Security found that several extensions in the Chrome Web Store and Edge Add-ons, with more than 8 million users combined, were collecting conversations with AI assistants and sending them to the developer's servers (The Register). They included a VPN and an ad blocker — extensions with no business looking at your chats at all. Collection covered ChatGPT, Claude, Gemini, DeepSeek, Perplexity and others, was on by default, and couldn't be turned off. According to the researchers, one of them even carried a "Featured" badge in the Chrome Web Store.

The takeaway is simple: a store badge, a high rating and millions of installs don't guarantee privacy. You have to check.

Checklist: 10 minutes before you install

1. Which sites it asks for

Open the store listing and find the permissions. A good sign: access only to the sites it needs — chatgpt.com, claude.ai and so on. A warning sign: "Read and change all your data on all websites". A chat organizer has no need for your email or your bank.

2. Where chat texts are stored

Look in the description or privacy policy for a direct answer to "are my chat texts stored on your server?" The options:

• "Only in your browser" — the best case. Check the fine print for exceptions.
• "End-to-end encrypted sync" — fine, if the key is derived from your passphrase on the device and the server only sees ciphertext.
• "We store data to provide sync" with no mention of encryption — the developer can read it.
• No answer — that's an answer too.

3. Which features send text out

Even a local-first extension may have features that need a server: AI summaries, translation, "smart" sorting. That's fine if:

• the feature only runs on your explicit action;
• before first use you see exactly what goes where;
• the developer says so plainly instead of hiding it behind "your data never leaves your browser".

4. What the store's privacy section says

Every Chrome Web Store listing has a section on the data an extension collects. In Firefox, since November 2025, new extensions must declare in their manifest whether they collect data, and the browser shows this at install time next to the permissions (Mozilla blog). Compare it with the description: a mismatch is a red flag.

5. Check the network yourself

It's easier than it sounds:

1. Open ChatGPT or Claude, press F12, and go to the Network tab.
2. Filter by Fetch/XHR.
3. Open a couple of chats and scroll.
4. Look at the domains. Requests to chatgpt.com or claude.ai are the site itself. Anything else deserves a look.

An extension's background requests don't show up in the page's tab. To see them, open chrome://extensions, turn on Developer mode, and click the service worker link for the extension: a separate DevTools window opens with its own Network tab.

Fine:       chatgpt.com/backend-api/…        ← the site's own request
Fine:       api.<developer>/license-…        ← key check, no chat text
Question:   collect.<something>.com/events   ← what exactly is being sent?

6. Who the developer is

Is there a website, a legal entity, a contact address, a dated privacy policy? An anonymous extension with access to all sites is a bad combination.

7. Updates and ownership changes

Extensions get sold. A new owner can ship an update that starts collecting data. If an update asks for new permissions (Chrome disables the extension and asks you to approve), don't click "Enable" without reading.

Quick reference

How Chatsavo handles it

This isn't a sales pitch; it's just easier to show the same checklist against an extension we know from the inside.

• Sites: only chatgpt.com, chat.openai.com and claude.ai. New AI sites will be added to the permissions one by one as support ships.
• Chat texts are stored only in your browser, in the extension's database. They go to a server only when you click "AI summary" yourself (a Pro feature coming in the next updates). Before the first use, you'll see a separate consent dialog.
• What our server sees: your key, a random device ID, the browser and the extension version, plus a hash of the device ID and subnet at trial start. Chat texts — never; chat titles and page URLs don't go either.
• Reading chats: a small script copies only the chat-list and chat-content responses the page already loaded on its own. It changes nothing and doesn't touch cookies or auth tokens. We make no requests of our own to AI sites.
• Firefox: the manifest declares no data collection (data_collection_permissions: none).
• Your data is yours: Settings → Your data lets you download everything as JSON or delete everything at any time. Your chats on the AI sites aren't affected.

Sync between devices will come later, end-to-end encrypted: the server gets only ciphertext.

Details are in the help center under Privacy. If you'd like to verify all of this against the checklist above, install Chatsavo and open DevTools — that's the idea.