Add to Chrome — free

Ask about one line, without losing your place.

Highlight text on any page and open a focused AI side-chat right where you're reading. Use your Claude login—or connect OpenAI, Anthropic, or Gemini—then add files, search the web, and choose the model for each question.

Add to Chrome — free See Pro pricing

No account. No servers. No tracking.

Highlight → Ask → a streamed answer. On Claude, GitHub, docs — anywhere.

The side-chatAsk about anything, right where you read it

Highlight → Ask on Claude, Gemini, and any page on the web. Answers stream in place; your main thread never forks.

See how it works ↓

Web MindAn encrypted memory that makes every answer yours

Your role, your projects, your documents — remembered on this device, briefed into every new chat, and always yours to review or delete.

Watch it learn ↓
See it in 90 seconds

Watch SubChat in action.

0
API keys
Runs on the claude.ai session you're already signed into.
0
servers
No SubChat backend exists. Your text can't visit it.
0
accounts
Install, highlight, ask. Pro is a license key, not an identity.
$0
extra AI spend
Your Claude plan does the talking. We never meter it.
How it works

Three seconds from doubt to answer.

Highlight

Select any text on any page — an Ask chip appears right next to it.

Ask

Type your side-question. It's seeded with your selection — and as much context as you choose.

Answer

The reply streams in place. Your main chat never scrolls, never forks.

Web Mind

It answers anywhere. And it knows you.

Encrypted here, never uploaded. Free keeps 10 memories and your documents; Pro adds ambient learning and the form Lens.

Features

Built for the way you actually read AI answers.

Long replies breed side-questions. Give each one a focused thread with the exact context, model, files, and live web access it needs—while your main conversation stays clean. Everything streams in place, with markdown, code copy, shortcuts, and both themes.

All seven are Pro · Free covers the core loop, 10 subchats a day.

Context modes

Pick how much of the main conversation rides along with your question. SubChat builds the seed for you — the answer knows what you know.

Many subchats at once

A thread per doubt. Drag, resize, minimize — each is its own conversation, and none of them touch your main chat.

History that stays local

Searchable, exportable as Markdown, never uploaded anywhere. Reopen any subchat where you left it.

Keep & Continue in Claude

Pin a subchat and it lives on in your own claude.ai history — renamed so you can find it — or promote it to a full conversation.

Every page on the web

GitHub, docs, papers, mail — highlight anything, anywhere, and ask your Claude about it. The page rides along as context.

Web search, files & models

Turn on live web search, attach text, code, PDF or DOCX, and pick the model per subchat — without leaving the floating workflow.

Never stuck on one engine

If Claude can't answer where you are, the request falls through your own order — Gemini, then your API key. The subchat just answers.

The architecture is the privacy policy

Your chats never meet our servers. We don't have any.

Every AI sidebar you've tried proxies your text through their backend to meter credits. SubChat can't read your conversations — nothing leaves your browser except the request to the AI you're already using.

  • Your own session, never a middlemanRequests ride the logged-in session you already have — like the site's own frontend.
  • No analytics, no trackingNot even anonymous pings. Nothing to opt out of, because nothing is collected.
  • Context lives on your machineSaved chats and optional Web Mind records stay local; Mind records are encrypted and deletable anytime.
Your browser
highlight + question
same-origin
Claude · Gemini
your own session
SubChat servers
do not exist
— there's no middleman to trust.
Compare

Everyone else resells tokens. You already have Claude.

AI sidebars charge monthly because they pay for every reply you generate. SubChat doesn't — your Claude plan does the talking.

SubChat Sider · Monica · Merlinthe subscription sidebars
Works with ClaudeChatGPTGemini Their backend, their credits
Monthly price Free · Pro $3.99/mo $8–25+/mo
Uses your Claude subscription Yes, your own session No
Replies metered by Only your plan's limits Daily credit packs
Account required None Sign-up
Your text routed through Nobody — your browser Their servers
Where the chat opens Right at your selection A sidebar panel

Competitor figures are paid monthly plans from public pricing pages (July 2026); annual billing is cheaper. Plans change often — check current rates. Names belong to their owners.

Launch week

People got it immediately.

Unedited, from the LinkedIn launch post.

"This is actually super cool and helpful — I often find myself having to open other chats so I don't drift off from my main topic. Great job 👏"

HM
Hashan M.Enterprise Architect Intern · Shake Shack

"Such a simple idea but I genuinely lose my train of thought every time I have to scroll back up mid-conversation. Installed it already."

DS
Dishant S.Developer

"This feels more contextual… it makes me wonder why Claude doesn't handle this natively. The onus shouldn't be on users to hack around long chats."

TC
Tanya C.Software Engineer · prev @ Meta

"I was wondering if there was any tool like this — losing track of the main thing in the chat is a huge problem for me. It should really be a feature Anthropic adds."

HP
Hunar P.Physics & AI Researcher · UIUC

"Asking too many follow-up questions makes the chat messier and increases the likelihood of context drift — this is a great tool to solve that. 👍"

MW
Maozhe W.MS in AI · SMU Cox

"Super helpful for when Claude brings up something I'm curious about but I don't want to sidetrack the main objective."

MC
Michael C.SWE Intern · Rajant Health
Pricing

One coffee a month. Not one more AI subscription.

SubChat has no token bill to pass on to you — so it doesn't. Pro is priced like the utility it is.

Free

For trying it — and staying, honestly
$0forever
  • Highlight → Ask on Claude and Gemini
  • 10 subchats a day, one at a time
  • Selection context
  • Streams, markdown, code copy, themes
  • Context Vault — add your own documents, 10 saved memories
Add to Chrome
Most popular

Pro

For people who think in side-questions
$3.99/month
Recurring — cancel anytime, no lock-in.
  • Everything in Free, unlimited
  • Context modes — nearby turns & whole chat
  • Unlimited simultaneous subchats
  • Searchable local history + Markdown export
  • Keep & Continue in Claude
  • Web mode — ChatGPT and any other website
  • Web search, file attachments & per-chat models
  • Web Mind — ambient learning, unlimited memory, Context Lens
  • Engine fallback order — never stuck when one provider is down
Limited time

Lifetime

Pay once. Never see a renewal again.
$149$69once
Less than 18 months of Pro — then it never costs anything again.
Launch price ends at 1,000 licenses
  • Everything in Pro, permanently
  • Every future Pro feature, free — Web Mind included
  • Locked at today's price, even when it goes up
  • One payment, no card on file, nothing to cancel

Every plan is a license key — no account, ever.

FAQ

The questions everyone asks.

Something else on your mind? Everything runs in your own browser on your own session — there's no server, and nothing to sign up for.

Do I need an API key?
No. SubChat runs on the AI session you're already signed into — on claude.ai and gemini.google.com its requests are the same calls the site's own frontend makes, carrying your existing cookies. On any other website it routes through your logged-in Claude tab. Nothing to paste, no per-token charges, no cost beyond the plan you already have. A free account works too.
Can you read my conversations?
We couldn't if we wanted to — there is no SubChat server. Your text goes from your browser straight to the AI you're using (Claude, Gemini, or your own API key), full stop. No analytics, no tracking, no accounts, nothing in the middle.
Where do my subchats go when I close them?
By default they're tidied away — each subchat is a real (hidden) conversation on your Claude account, deleted when you close the widget. On Pro, transcripts are also saved locally in your browser, and the pin button keeps the conversation alive in your own claude.ai history, renamed so you can find it.
How do I pay, and how do I cancel?
Pick a plan at checkout — your license key is emailed instantly, and you paste it into the SubChat dashboard to unlock everything. Monthly and yearly are recurring; you can cancel anytime from the customer portal (a link is in your confirmation email and in the dashboard), and you keep access until the period you paid for ends. Lifetime is a one-time payment. Payments are handled by our merchant of record, so we never see your card.
Does it work with ChatGPT or Gemini?
Both. On gemini.google.com SubChat uses your Gemini session; on claude.ai it uses Claude. Everywhere else it routes through your Claude tab, and if that's unavailable it can fall back to Gemini or your own API key — so you're never stuck. ChatGPT is supported best-effort (OpenAI actively blocks automation), with the same Claude/Gemini fallbacks behind it.
Is SubChat affiliated with Anthropic?
No. SubChat is an independent project and isn't affiliated with, endorsed by, or sponsored by Anthropic. "Claude" is a trademark of Anthropic, used here only to describe compatibility.

Your next side-question
deserves its own thread.

Free to start, nothing to sign up for, and everything it learns stays in this browser.

Add to Chrome — free See Pro pricing
No account · No servers · No tracking