A sidebar extension puts an AI assistant in a panel beside whatever page you are reading, so you can ask about it without switching tabs. DeepSeek sidebar extensions do this for DeepSeek’s models, in both Chrome and Edge.
This guide covers what they do, what to check before installing one, and the privacy question that matters most with this particular provider.
Checked August 2026. Extensions in this category change hands and change behaviour frequently — the guidance below is deliberately about how to evaluate one rather than which to install.
What DeepSeek is
DeepSeek is an AI company whose models became widely known for delivering strong results at a much lower cost than the established alternatives. Several of its models are open-weight, meaning they can be downloaded and run on your own hardware — which is unusual and genuinely significant.
The distinction that matters for a browser extension: using the DeepSeek API or website sends your text to DeepSeek’s servers. Running an open-weight model locally does not. Almost every browser extension does the former.
The privacy question
DeepSeek is a Chinese company, and its consumer service stores user data on servers in China. That is stated in its own privacy policy, and it is a material difference from US-based providers, not a rumour. Several governments and organisations have restricted the app on official devices for this reason.
For asking about a news article, that may not matter to you. For anything work-related, confidential, or personally sensitive, it should factor into the decision — and on a work device, check your organisation’s policy before installing anything that routes page content to it.
The same caution applies in the other direction: a browser extension that reads your pages sends that content somewhere regardless of provider. The question is always where, and whether you are comfortable with it.
Before installing any sidebar extension
These extensions need permission to read and change the content of every page you visit — that is how they see the page you are asking about. It is the same level of access as a password manager.
- Check the publisher. Is there an identifiable company or person, with a website and a privacy policy naming an entity? DeepSeek’s own name appearing in the extension title does not mean DeepSeek published it. Most are third-party.
- Read recent reviews. Sort by newest and read the one-star ones. Popular extensions get sold, and new owners can push updates silently to everyone who already has it installed.
- Look at what it asks for. An extension that also wants access to your browsing history, downloads or clipboard is asking for more than a sidebar needs.
- Set site access to “On click”. After installing, go to
chrome://extensions(oredge://extensions) → Details → Site access. If the extension works this way, it then does nothing on pages where you have not invoked it. This is the single most effective control available.
See how to choose an AI browser extension safely for the wider version of this.
Alternatives that need no permissions
Worth considering before granting page access to anything:
- Use the website in a pinned tab. Paste in what you want help with. No extension, no permissions.
- Install it as a web app. In Chrome: three-dot menu → Cast, save and share → Install page as app. It gets its own window and taskbar entry.
- Run a model locally. Tools such as Ollama or LM Studio run open-weight models on your own machine. Nothing leaves the computer. It needs a reasonable amount of RAM and, ideally, a GPU — but for anyone whose objection is data leaving their machine, this is the answer that actually addresses it.
What sidebars are good and bad at
Good: summarising a long page before you commit to reading it; explaining an unfamiliar concept in context; drafting a reply without leaving the page; explaining an error message.
Bad: anything factual you will rely on without checking — a summary inherits every error in the source and adds its own; and anything confidential, since the page content is transmitted.
If the sidebar stops working
- Update the extension:
chrome://extensions→ turn on Developer mode → Update. - Check the provider’s status. A sidebar that returns errors is usually reporting a server-side problem — see what AI service errors actually mean.
- Test in a private window with other extensions off, to rule out a conflict. Note that extensions are disabled in incognito by default — see enabling extensions in incognito.
- Reinstall it if signing in fails repeatedly.
Frequently asked questions
Is DeepSeek free to use?
Its consumer service has a free tier, and its API is priced well below most competitors. Extensions may add their own subscription on top, or ask for your own API key — check which before installing.
Is it safe to use?
The model works. The question is where your data goes: DeepSeek’s consumer service stores data on servers in China. Judge that against what you intend to paste, and check your employer’s policy on a work device.
Can I run DeepSeek without sending data anywhere?
Yes, if you run an open-weight model locally with a tool such as Ollama or LM Studio. That is the only configuration where nothing leaves your machine.
Does the extension read every page I visit?
If site access is set to “all sites”, it can. Set it to “on click” so it only acts when you ask.
Does it work in Edge as well as Chrome?
Chrome extensions install in Edge, and the settings are in the same place at edge://extensions. The same checks apply.
How does it compare with ChatGPT or Copilot?
For everyday questions the difference is smaller than the marketing suggests. The meaningful differences are cost, and where your data is processed — see what ChatGPT is and Copilot on Windows.
