Create subthreads on any AI conversation

Select any text in ChatGPT, Claude, or Gemini to start a focused side conversation—without cluttering your main chat.

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chatgpt.com
Tell me some fun facts about Central Park in New York City
It's a major bird migration stop

Over 280 bird species have been recorded there because the park acts as a green oasis in the middle of dense urban Manhattan.

There's a reservoir bigger than Monaco's parkland

The Jacqueline Kennedy Onassis Reservoir alone covers about 106 acres.
Thread
Over 280 bird species have been recorded there because the park
What are some of the most popular bird species?
Some of the most commonly seen birds in Central Park include:

American Robin – often seen hopping on lawns looking for worms.

Northern Cardinal – Bright red males, easiest to spot in The Ramble.

Blue Jay – Loud and bold…
3 Platforms
ChatGPT, Claude, Gemini
100% Free
No premium tiers
Zero Config
No API keys needed
Privacy First
No data leaves your browser
Features

Everything you need to think deeper

SideNote adds a layer of threaded exploration to the AI tools you already use.

Persistent Highlights

Anchored text stays highlighted across reloads

Your thread anchors are saved and re-applied when you return to a conversation. Highlighted passages show exactly where each subthread originated.

Tell me about the history of the Colosseum
The Colosseum could hold up to 80,000 spectators and was used for gladiatorial contests and public spectacles for nearly 400 years. It was built using an estimated 100,000 cubic meters of travertine stone held together with iron clamps rather than mortar.
How did they build it so fast?
Construction took about 8 years (72–80 AD). Emperor Vespasian funded it using spoils from the Siege of Jerusalem. Tens of thousands of Jewish slaves did the labor.
Threaded Conversations

Branch off any AI response into a focused subthread

When an AI response sparks a follow-up question about a specific detail, create a subthread instead of derailing your main conversation. Each thread is anchored to the exact text you selected.

What makes the Great Barrier Reef so unique?
The Great Barrier Reef is the world's largest coral reef system, stretching over 2,300 km. It contains over 1,500 species of fish and 400 types of coral, making it one of the most biodiverse ecosystems on Earth.
Thread
over 1,500 species of fish
What are some of the most notable fish species?
Some iconic species include clownfish, parrotfish, and reef sharks…
Ghost Mode

Your main chat stays perfectly clean

Subthread messages use your chat session but dont dont end up cluttering your chat. Your main conversation reads as if the side exploration never happened.

What is the difference between supervised and unsupervised learning?
Supervised learning uses labeled data to train models, while unsupervised learning finds patterns in unlabeled data…
Great, can you give me a practical example of each?
A common example of supervised learning is email spam detection, while unsupervised learning is used for customer segmentation…
Zero Configuration

No API key required. Uses the host AI directly.

SideNote sends your subthread questions through the AI platform you're already using. No separate accounts, no API keys, no extra costs. Install and go.

No API keys to configure
No account creation required
No data sent to external servers
Works with your existing AI subscription
How It Works

Three steps to deeper understanding

No setup, no API keys, no accounts. Just install and start threading.

Select any text

Highlight a passage in any AI response that you want to explore further.

Click “Thread”

A floating button appears above your selection. Click it to open a subthread panel.

Explore deeper

Ask follow-up questions in a focused side conversation. Your main chat stays clean.

Platforms

Works where you already chat

SideNote integrates directly into the AI platforms you use every day. Same workflow everywhere.

ChatGPT Claude Gemini

Frequently Asked Questions

What is SideNote?
SideNote is a free Chrome extension that adds threaded subconversations to ChatGPT, Claude, and Gemini. Select any text in an AI response to branch into a focused side conversation without cluttering your main chat.
Does SideNote require an API key?
No. SideNote works directly with your existing ChatGPT, Claude, or Gemini session. It sends subthread messages through the host AI platform, so there is no API key to configure and no separate account to create.
Which AI platforms does SideNote support?
SideNote works with ChatGPT (chatgpt.com and chat.openai.com), Claude (claude.ai), and Google Gemini (gemini.google.com). The same workflow works across all three platforms.
Is SideNote free?
Yes, SideNote is completely free with no premium tiers, no usage limits, and no hidden costs. It will always be free to use.
What is Ghost Mode?
Ghost Mode automatically hides subthread messages from your main chat view. Your main conversation reads as if the side exploration never happened, keeping it clean and easy to follow while your deep-dive is preserved in the thread panel.
How is SideNote different from other ChatGPT extensions?
Unlike sidebar chat extensions, prompt managers, or AI writing tools, SideNote introduces threaded subconversations directly anchored to specific text in AI responses. You can branch off any part of an answer to explore a detail deeper, then return to a clean main chat. This threading approach is unique among ChatGPT Chrome extensions.
Does SideNote collect my data?
No. SideNote stores thread data locally in your browser using Chrome's built-in storage API. No data is sent to external servers, no analytics are collected, and no account is needed.
Which browsers does SideNote work on?
SideNote is available on the Chrome Web Store and works on Google Chrome, Microsoft Edge, Brave, and Opera—any Chromium-based browser that supports Chrome extensions.

Ready to go deeper?

Stop cluttering your AI conversations with tangential questions. Create focused subthreads and explore ideas without losing context.

Add to Chrome
No data leaves your browser. No API keys. No accounts.